Summer Homework BookletBiology Core Science Higher Revision

This booklet is to help you prepare for your real and mock exams over the next year. Please tick in the table below when you have completed each section. The key words are there to help you, but you might like to make some revision resources for any you’re struggling with. Make sure you’re using your revision guide, BBC Bitesize (http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel/), etc. to help you.

You will be tested on the knowledge tests in September. It’s important that these facts are easy to recall so you should aim for a score of 90%+. Make sure you’ve attempted the tests a few times and recorded your results below. We’re not expecting 100% straight away; we just want to see progress!

Topic Tracking Sheet

20 Questio

ns

Summary

SheetsKey

Words1. Classification2. Genetics3. Homeostasis - Nervous

System4. Homeostasis - Hormones5. Drugs and Disease6. Interdependence

Knowledge Tests

Date Score Percentage

Learning objectives Reflection point 1

Reflection point 2

Reflection point 3

1.1 Describe how biologists classify living organisms according to how closely they are related to one another including:

a Species b Genus c Family d Order e Class f Phylum g The Five Kingdoms

1.2 Describe the main characteristics of the five kingdoms including

a Animalia b Plantae c Fungi d Protoctista e Prokaryotae

1.3 Explain why scientists do not classify viruses in any of the five kingdoms and regard them as non-living.

1.3 Describe that all vertebrates have a spinal cord and therefore are chordates.

1.4 Describe the main characteristics of the phylum chordata as animals with a supporting rod running the length of the body, an example of this being the backbone in vertebrates.

1.5 Explain how scientists place vertebrates into groups based on

a oxygen absorption methods – lungs, gills and skin

b reproduction – internal or external fertilisation, oviparous or viviparous

c thermoregulation – homeotherms and poikilotherms

d body covering – fur / hair, feathers, dry scales, moist skin, and wet scales.

1.6 Outline the problems with classifying vertebrates to a specific group based on their characteristics and why many vertebrates are difficult to classify.

1.7 Discuss why the definition of a species as organisms that produce fertile offspring may have limitations:

a some organisms do not always reproduce sexually (bacteria do not interbreed they simply divide) and

b sometimes different species do interbreed to produce hybrids and some are fertile (eg mallard ducks)

Core Biology Topic 1: Classification, variation and

inheritance

H 1.8 Explain why binomial classification is needed to identify and study species.

1.9 Explain how accurate classification may be complicated by:

a variation within a species H b hybridisation in ducks H c ring species

Learning objectives Reflection point 1

Reflection point 2

Reflection point 3

1.19 Explain the role of the scientific community in validating new evidence, including the use of:

a scientific journals

b the peer review process

c scientific conferences

H 1.8 Explain why binomial classification is needed to identify, study and conserve species, and can be used to target conservation efforts

1.10 Construct and use keys to show how species can be identified

1.13 Describe variation as continuous or discontinuous

1.14 Investigate the variations within a species to illustrate continuous variation and discontinuous variation

1.11 Explain how organisms are adapted to their environment and how some organisms have characteristics that enable them to survive in extreme environments, including deep-sea hydrothermal vents and polar regions

1.15 Interpret variation graphs using normal distribution curves

1.16 Describe the causes of variation, including:

a genetic variation – different characteristics as a result of mutation or reproduction

b environmental variation – different characteristics caused by an organism’s environment (acquired characteristics)

1.12 Demonstrate an understanding of Darwin’s theory of evolution by natural selection including

a variation b over-production c struggle for existence

d survival e advantageous characteristics inherited

f gradual change

H 1.17 Explain how speciation occurs as a result of geographical isolation

1.18 Explain how evidence from DNA research and the emergence of resistant organisms support Darwin’s theory.

1.20 Describe the structure of the nucleus of the cell as containing chromosomes, on which genes are located.

1.21 Explain that genes exist in alternative forms called alleles which give rise to differences in inherited characteristics.

1.22 Recall and use the meaning of the terms: dominant, recessive, homozygous, heterozygous, phenotype and genotype

Learning objectives Reflection point 1

Reflection point 2

Reflection point 3

1.23 Analyse and interpret patterns of monohybrid inheritance using a genetic diagram and Punnett squares

Examples: Using / drawing punnet squares and pedigree analysis diagrams.

1.24 Calculate and analyse outcomes from monohybrid crosses.

(using probabilities, ratios and percentages)

1.25 Describe the symptoms of the genetic disorders and explain why these symptoms occur:

a sickle cell disease

b cystic fibrosis

H 1.26 Evaluate the outcomes of pedigree analysis when screening for genetic disorders and explain why pedigree analysis might be necessary for an individual:

a sickle cell disease

b cystic fibrosis

Areas I need to work on – reflection point 1:

Areas I need to clarify – reflection point 2:

Learning objectives Reflection point 1

Reflection point 2

Reflection point 3

2.1 Define homeostasis as the maintenance of a stable internal environment2.2 Describe the homeostatic mechanisms of:

a thermoregulation and the effect of temperature on enzymes

b osmoregulation

c blood glucose regulation

2.3 Explain how the skin helps thermoregulation take place, including:

a the role of the dermis – sweat glands, blood vessels, nerve endings, hair, erector muscles and sebaceous glands

b the roles of the hypothalamus – regulating body temperature

H 2.4 Explain how thermoregulation takes place, with reference to:

a vasoconstriction and

b vasodilation

c negative feedback

2.20 Explain the structure and function of dendrons and axons in the nervous system

2.21 Describe how stimulation of receptors in the sense organs sends electrical impulses along neurones

2.22 Investigate human responses to external stimuli

2.10 Explain how a coordinated response to a stimulus is achieved, including the roles of the synapse and neurotransmitters

2.23 Describe the structure and function of sensory, relay and motor neurones and synapses including:

a the role of the myelin sheath

b the roles of neurotransmitters

c the reflex arc

2.5 Recall that hormones are produced in endocrine glands and are

Core Biology Topic 2: Responses to a changing

environment

transported by the blood to their target organs

2.6 Explain how blood glucose levels are regulated by insulin and excess blood glucose is converted to glycogen in the liver

Learning objectives Reflection point 1

Reflection point 2

Reflection point 3

2.9 Explain how Type 1 diabetes can be controlled, including the roles of diet and injection of insulin usually into the subcutaneous fat

2.10 Explain how, in Type 1 diabetes, the level of physical activity and diet affect the amount of insulin required

2.11 Recall that Type 2 diabetes is caused by a person becoming resistant to insulin

2.12 Explain how Type 2 diabetes can be controlled by diet and physical activity

2.13 Evaluate the correlation (link) between obesity (including calculations of BMI) and Type 2 diabetes

2.16 Investigate tropic responses

2.14 Explain how plant growth substances (hormones) bring about:

a positivism phototropism in shoots (plant growing towards the light).

b positive gravitropism (geotropism) in roots (roots growing downwards into the ground)

2.15 Explain how auxins bring about short curvature (bending in the stem) using cell elongation

2.17 Analyse, interpret and evaluate data from plant hormone experiments, including the action of auxins and gibberellins

H 2.18 Demonstrate an understanding of the uses of plant hormones, including:

a selective weedkillers b rooting powder

c seedless fruit d fruit ripening

Areas I need to work on – reflection point 1:

Areas I need to clarify – reflection point 2:

Core Biology Topic 3: Problems of and solutions to a

changing environmentLearning objectives Reflectio

n point 1Reflection point 2

Reflection point 3

3.1 Define a drug as a substance, such as a narcotic or hallucinogen, that affects the central nervous system causing changes in psychological behaviour and possible addiction

3.2 Describe the general effects of:

a painkillers that block nerve impulses, including morphine

b hallucinogens that distort sense perception (make you see / feel / hear things that are not there), including LSD

c stimulants that increase the speed of reactions and neurotransmission at the synapse, including caffeine

d depressants that slow down the activity of the brain, including alcohol

3.3 Investigate reaction times

3.4 Explain the effects of some chemicals in cigarette smoke, including:

a nicotine as an addictive drug

b tar as a carcinogen

c carbon monoxide reducing the oxygen-carrying ability of the blood

3.5 Evaluate data relating to the correlation (link) between smoking and its negative effects on health (Be able to say what graphs / tables of data are showing). You may need to be able to calculate a percentage or a difference.

3.6 Evaluate evidence of some harmful effects of alcohol abuse:

a in the short term – blurred vision, lowering of inhibitions, slowing reactions of

b in the long term – liver cirrhosis, brain damage

3.7 Explain the ethics of organ transplants, including:

a liver transplants for alcoholics (arguments for and against them being allowed a liver transplant)

b heart transplants for the clinically obese (arguments for and against them being allowed a heart transplant)

c the supply of organs (how many people need them on the waiting lists and how many organs are actually available).

Areas I need to work on – reflection point 1:

Areas I need to clarify – reflection point 2:

Learning objectives Reflection point 1

Reflection point 2

Reflection point 3

3.8 Recall that infectious diseases are caused by pathogens

3.9 Describe how pathogens are spread, including:

a in water, including cholera bacterium

b by food, including Salmonella bacterium

c airborne (eg sneezing), including influenza virus symbols

d by contact, including athlete’s foot fungus e by body fluids, including HIV

f by animal vectors, including: i housefly: dysentery bacterium

ii Anopheles mosquito: malarial protozoan

3.10 Explain how the human body can be effective against attack from pathogens, including:

a physical barriers – skin, cilia, mucus

b chemical defence – hydrochloric acid in the stomach, lyozymes in tears

3.11 Explain that plants produce chemicals that have antibacterial effects in order to defend themselves, some of which are used by humans

3.12 Describe how antiseptics can be used to prevent the spread of infection

3.13 Explain the use of antibiotics to control infection, including:

a antibacterials to treat bacterial infections

b antifungals to treat fungal infections

H 3.14 Evaluate evidence that resistant strains of bacteria, including MRSA, can arise from the misuse of antibiotics

3.15 Investigate the effects of antiseptics or antibiotics on microbial cultures

3.16 Recall that interdependence is the dynamic relationship between all living things (Food chains and webs / how living organisms depend on each other)

3.17 Demonstrate an understanding of how some energy is transferred to less useful forms at each trophic level and this limits the length of a food chain

3.18 Demonstrate an understanding that the shape of a pyramid of biomass is determined by energy transferred at each trophic level

Learning objectives Reflection point 1

Reflection point 2

Reflection point 3

3.19 Explain how the survival of some organisms may depend on the presence of another species:

a parasitism, including:

i fleas ii headlice iii tapeworms iv mistletoe

b mutualism, including:

i oxpeckers that clean other species ii cleaner fish

H iii nitrogen-fixing bacteria in legumes

H iv chemosynthetic bacteria in tube worms in deep-sea vents

3.20 Analyse, interpret and evaluate data (graphs and tables) on global population change

3.21 Explain how the increase in human population contributes to an increase in the production of pollutants, including phosphates, nitrates and sulfur dioxide

3.22 Explain eutrophication and the problems associated with eutrophication in an aquatic environment

3.23 Investigate the effect of pollutants on plant germination and growth

3.24 Demonstrate an understanding of how scientists can use the presence or absence of indicator species to assess the level of pollution:

a polluted water indicator – bloodworm, sludgeworm

b clean water indicator – stonefly, freshwater shrimps

c air quality indicator – lichen species, blackspot fungus on roses

3.25 Demonstrate an understanding of how recycling can reduce the demand for resources and the problem of waste disposal, including paper, plastics and metals

3.26 Demonstrate an understanding of how carbon is recycled

a during photosynthesis plants remove carbon dioxide from the atmosphere

b carbon compounds pass along a food chain

c during respiration organisms release carbon dioxide into the atmosphere

d decomposers release carbon dioxide into the atmosphere

e combustion of fossil fuels releases carbon dioxide into the atmosphere

Learning objectives Reflection point 1

Reflection point 2

Reflection point 3

3.27 Demonstrate an understanding of how nitrogen is recycled a nitrogen gas in the air cannot be used directly by plants and

Areas I need to work on – reflection point 1:

Areas I need to clarify – reflection point 2:

B1 Higher Knowledge Test1. Complete this table naming the 5 kingdoms and give 2 features of each kingdom.

Kingdom 2 features

2. Give two reasons why scientists classify viruses as non-living.3. Define the term ‘species’.4. What are the two limitations to the definition of a species?5. The phylum Chordata all have what feature in common?6. What are the three reasons that make classification difficult?7. What are the three different ways of absorbing oxygen found in vertebrates?8. What do oviparous animals do?9. What do homeotherms do?10. What is a hybrid?11. ‘Differences between individuals’ is better known as…?12. What is the binomial name for human beings?13. Name two vertebrate groups that have lungs?14. What are the two types of variation and give an example of each?15. Draw a normal distribution curve.16. What are the two causes of variation?17. What is a mutation?18. State the 6 stages of natural selection.19. Describe two adaptations of the polar bear.20. What is a gene?21. Define the term allele.22. Using appropriate symbols, write down the genotype of a person who is heterozygous?23. Using appropriate symbols, write down the genotype of a person who is homozygous recessive?24. What does the term phenotype mean?25. Give 2 symptoms of Sickle Cell Anaemia26. Give 2 symptoms of Cystic Fibrosis.27. Define Homeostasis.28. Which part of the brain controls body temperature?29. What method of heat energy transfer does sweating utilise to cool us down?30. Explain why we look red when we are hot?31. What does negative feedback mean?32. What makes up the central nervous system?

33. What are the cells in your eye that detect light?34. What part of the neurone transmits information to different neurons, muscles and glands?35. What is the function of a dendrite?36. Define a synapse and state the generic name for the chemical that crosses it. 37. What is the myelin sheath made of and what is its role?38. What is the name given to the quick response that protects us from harm?39. How are hormones transported around the body?40. What hormone reduces blood sugar levels?41. What is excess glucose stored as?42. Where is excess glucose stored?43. What hormone acts in the opposite way to insulin?44. What causes type 1 diabetes and how could type 1 diabetes be controlled?45. What causes type 2 diabetes give 2 ways type 2 diabetes can be controlled?46. Where is insulin produced?47. What is phototropism?48. If a tropism is positive, what does this mean?49. What is geotropism?50. Name a plant hormone.51. What effect does light have on auxin?52. What is a drug?53. Complete this table to list the 4 main types of drug, how they affect the body and an example of each.

Type of drug Example Effect on body

54. Name the addictive drug in cigarette smoke.55. What does the term ‘carcinogen’ mean?56. Which chemical in cigarette smoke is a carcinogen?57. State 2 short term effects of alcohol use.58. State 2 longer term effects of alcohol use.59. Name three groups of pathogens60. What disease is increasing in hospitals due to antibiotic resistance?61. What does an antiseptic do?62. Give two chemical methods a human uses to avoid infection.63. What do parasites do to their host?64. What is the advantage of the ox pecker bird to the ox?65. Where would you find mistletoe growing?66. What type of relationship is where 2 organisms live together and both benefit?67. What do cleaner fish eat?68. Describe three ways that C02 can get into the environment.69. What group of plants have nitrogen fixing bacteria in their roots?70. What type of bacteria turn nitrogen from the air into nitrates?

B1 Higher Knowledge test Answers

1.

Kingdom 2 featuresAnimalia multicellular, no cell walls, no chlorophyll, feed

heterotrophicallyPlantae multicellular, have cell walls, have chlorophyll, feed

autotrophicallyFungi multicellular, have cell walls, no chlorophyll, feed

saprophyticallyProtoctista unicellular, have a nucleus

Prokaryote unicellular, have no nucleus

2. Cannot reproduce without a host, cannot move, not made of cells, doesn’t have a cell membrane3. A group of similar organisms that can reproduce to give fertile offspring4. Some organisms reproduce asexually. Some hybrids are fertile.5. Backbone/supporting rod6. Variation, ring species, hybridisation7. Gills, lungs, skin8. Lays eggs9. Maintain their body temperature (warm blooded)10. The offspring of two plants or animals of different species or varieties, such as a mule.11. Variation12. Homo sapien13. Mammals, birds14. Continuous e.g. height, weight and discontinuous e.g. eye colour, hair colour, blood group

15.16. Genes and environment17. A change in an organisms DNA18. Variation, Over production, struggle for existence, survival, advantageous characteristic inherited, gradual

change19.20. A section of DNA/a chromosome that codes for a

particular characteristic. 21. A version of a gene22. Any letter Hh23. hh 24. The outward characteristics caused by the genes25. Painful joints, fatigue, shortness of breath, irregular

heart beat, jaundice

Feature Reason

Small ears Reduce heat loss

Thick fur Insulation

Large feet Spread weight, help swimming, stop it sinking in the snow

Rough soles Grip

Thick blubber Insulation

White fur Camouflage

26. Persistent cough, recurrent chest infections, mucus in the lungs, infertility, underweight, does not produce digestive enzymes

27. The maintenance of a stable internal environment28. Hypothalamus29. Evaporation30. Vasodilation allowing more blood to the skins surface to increase heat energy loss31. When a change in one direction is detected a mechanism reverses the change. 32. Brain and Spinal cord33. Light sensitive cells in the retina34. Axon35. Connect neurones36. The junction between two neurones, Neurotransmitter37. Fat, Insulate the axon38. Reflex39. Blood40. Insulin41. Glycogen42. Liver and muscles43. Glucagon44. Lack of insulin, Controlled diet and injecting insulin45. A person being resistant to insulin, Physical activity and diet46. Pancreas 47. A growth response to light48. Towards the stimulus49. A growth response to gravity50. Auxin or gibberellin51. Breaks it down52. A chemical that causes a change53. .

Type of drug Example Effect on bodyPainkiller Morphine Blocks nervous impulsesDepressant Alcohol Slows reactionsStimulant Caffeine Speeds up reactionsHallucinogen LSD Distorts/changes senses and

perceptions

54. Nicotine55. Causes cancer56. Tar57. Blurred vision, lowering of inhibitions, slowing of reactions (Not gets you drunk)58. Liver cirrhosis, brain damage59. Bacteria, virus, fungi, protozoa60. MRSA61. Kills bacteria outside the body62. Lysosyme in tears, stomach acid, mucus63. Feeds off them64. Eats parasitic insects from it65. On another tree66. Mutualism67. Dead skin from other fish68. Respiration, burning fossil fuels, decomposition69. Legumes70. Nitrogen fixing bacteria

1) What is the function of the nucleus in the cell? (1 mark)

2) Name the 5 kingdoms (5 marks)

3) Name the main differences between organisms in the animalia kingdom and plantae kingdom (3 marks)

4) How can you tell the difference between protocista and prokaryotae? (1 mark)

5) What does the word chordate mean? (2 marks)

6) What are the main characteristics of a bird? (What do we look for when we classify it?) (4 marks)

7) What do we mean by an a) homeotherm b) poikilotherm? (2 marks)

8) How do amphibians absorb oxygen? (2 marks)

9) What do we mean by the term species? (2 marks)

10) What do we mean by the term hybrid? (2 marks)

ClassificationName:

Marks: /53

11) What are the three limitations of the definition of a species? (3 marks)

12) Binomial means “2 names”. The binomial name for polar bears is Ursus maritimus. maritimus refers to which level of classification (1 mark)

13) Can you explain why binomial classification is useful when we are trying to identify and study species?

(3 marks)

14) What is a ring species? How do ring species make classification difficult? (3 marks)

15) Name the 2 types of variation and give examples of each (2 + 2 marks)

16) Which type of variation would be displayed on a) a bar chart, b) a normal distribution curve? (2 marks)

17) Name 3 ways in which a polar bear is adapted to survive in its environment (3 marks)

18) Name 3 ways in which the Pompeii worm is adapted to survive in its environment. (3 marks)

19) Name 2 changes in the environment that might lead to speciation. (2 marks)

20) In an exam you might be asked how a particular species has evolved. What are the key pieces of information that you need to include in your answer? (5 marks)

READ THE MARKSCHEME CAREFULLY AS THERE ARE SOME HINTS HERE, YOU NEED TO HAVE THE WORDS IN BOLD FOR THE FULL MARKS, IF YOU HAVEN’T GOT THEM IN YOUR ANSWERS, MAKE SURE YOU LEARN THEM FOR THE EXAM.1. What is the function of the nucleus in the cell? (1 mark) Controls the cell (1), contains the genetic material – DNA for reproduction (1)

2. Name the 5 kingdoms (5 marks) Plantae (1), animalia (1) fungi (1), protoctists (1)prokaryotes (1)

3. Name the main differences between organisms in the animalia kingdom and plantae kingdom (3 marks) Note: As the question asks for differences, you won’t get the mark unless you have made a direct comparison

Plantae are autotrophs, (produce their own food) animalia are heterotrophs (move about, find and hunt own food). (1)

Plantae have a cell walls to support the cell, animalia do not (1) Plantae contain chloroplasts which contain chlorophyll, animalia do not (1)

4. How can you tell the difference between protocista and prokaryotae? (1 mark)

ClassificationName:

Marks: /53

Note: Again , you have been asked for a difference , therefore it needs to be direct comparison Protoctists have a nucleus (e.g. algae), prokaryotes do not contain a nucleus (e.g bacteria)

5. What does the word chordate mean? (2 marks) They have a supporting rod like structure (1) called a backbone or spinal cord (1)

6. What are the main characteristics of a bird? (What do we look for when we classify it?) (4 marks)

Absorption of oxygen – they breathe in through lungs (1) Reproduction method – Oviparous, lay eggs (1) Regulation of body temperature – homeotherms (1) Body covering – Feathers (1)

7. What do we mean by an a) homeotherm b) poikilotherm? (2 marks) Note: If you don’t specify which is which then you won’t get the mark Homeotherms maintain their body temperature by homeostasis, warm blooded) (1) Poikilotherm – Cold blooded, body temperature changes with external temperature (1)

8. How do amphibians absorb oxygen? (2 marks) Through gills when they are young and then skin when they are adults (2)

9. What do we mean by the term species? (2 marks) Organisms can interbreed (1) to produce fertile offspring (1)

10. What do we mean by the term hybrid? (2 marks) When a male from one species breeds with a female from another species (1) to produce a fertile offspring (1)11) What are the three limitations of the definition of a species? (3 marks) Note: Any 3 of the following will get you the mark: Always link back to the main definition of the term species:

Not all species interbreed as the definition suggests, some species like plants reproduce asexually but they still produce clones of themselves that are the same species. (1)

Some hybrids produce fertile offspring but they are not members of the same species (1)

Members of the same species should looks similar but there are many variations within a species e.g. different breeds of dogs but they are still members of the same species (1)

You have ring species, this is a group of related populations that live in neighbouring areas. Populations that live near each other can interbreed to produce fertile offspring, those that live further apart cannot interbreed but are still the same species. (1)

12) Binomial means “2 names”. The binomial name for polar bears is Ursus maritimus. Maritimus refers to which level of classification (1 mark) Maritimus – Species name (1)

13) Can you explain why binomial classification is useful when we are trying to identify and study species (3 marks) Note: Any 3 of the following , however if it is a 4 or 6 mark question then you will need them all.

It avoids confusion when organisms have common names but are different species in different places e.g. the American and English robin (1)

Scientists can easily study and share information on them. (1) It is easier to identify species that are endangered we can therefore conserve

the species. It’s easy to presume that 2 similar looking organisms are the same species when they are different. Only one species might be protected whilst the other becomes extinct. (1)

Can target conservation projects – can protect areas that have the greatest variety of different species (biodiversity) to prevent huge number of species being destroyed. (1)

14) What is a ring species? How do ring species make classification difficult? (3 marks)

According to the definition of the term species, members of the same species should be able to interbreed and produce fertile offspring (1).

A ring species is group of related populations that live in neighbouring areas. Populations that live near each other can interbreed to produce fertile offspring whilst those that live further apart cannot interbreed but are still the same species. (1).

This goes against the definition of the terms species and makes classification difficult (1)

15) Name the 2 types of variation and give examples of each (2 + 2 marks) Note: Always read the question to see if it is asking you about animal, plant or micro-organims

examples, if it doesn’t specify (as in the question above) then any question will get you the mark.Continuous variation (1) e.g. animals vary in height, weight, shoe size, (1) micro-organisms vary in width, (1) plants vary in height (1) Discontinuous (1) – animals vary in; eye colour, blood type, (1) Micro-organisms vary in: antibiotic resistance or not (1) plants: colour of courgette, yellow, dark green, light green.

16) Which type of variation would be displayed on a) a bar chart, b) a normal distribution curve? (2 marks) Bar chart – Discontinuous variation Normal distribution curve –continuous variation

17) Name 3 ways in which a polar bear is adapted to survive in its environment (3 marks) Note: Always link the adaptation to why this allows it to survive no matter which organism they have asked about, they could ask about a penguin.

Big feet helps to spread the weight and reduce pressure on the ice, stops them sinking into the snow or breaking thin ice (1)

Compact round shape which gives a small surface area to volume ratio, this reduces heat loss (1)

Thick layer of blubber for insulation to reduce heat loss, also acts as an energy store when food is scarce (1)

Thick hairy coats to trap a layer of warm air next to the skin to help warm the body.Greasy fur sheds water to prevent cooling by evaporation. (1)

Have white fur to match surroundings for camouflage (1)

18) Name 3 ways in which the Pompeii worm is adapted to survive in its environment. (3 marks)

They have mutualistic relationships with bacteria, bacteria live on the worm and can produce their own food using chemical energy (chemosynthesis), the work uses this food , they are producers (1)

The bacteria are adapted to cope with high pressure and temperature (1) Pompeii worms don’t have eyes (1)

19) Name 2 changes in the environment that might lead to speciation. (2 marks)

Geographic isolation , populations are separated by physical barriers e.g. floods (1) or earthquakes (1)

20) In an exam you might be asked how a particular species has evolved. What are the key pieces of

information that you need to include in your answer? (5 marks) Note: In an exam you will often have to apply it to an example of the development of a particular species in a particular environment.

There is always variation in a species (1) Name the species in the example Most species give birth to more young than can survive to adult hood (1) Individuals compete to survive in their environment (1) What are they

competing for in the example that they have given you. Those that have characteristics that are better adapted to compete have a

better chance of survival (survival of the fittest). (1) Which feature in the example would help the animal survive?

Genes with this characteristic will be passed on when the species reproduces. (1) Remember, species need to reproduce if they are going to pass the genes on to the next generation, if you don’t reproduce then you won’t pass on the characteristics and the species won’t evolve over time.

The individuals that are less adapted are less likely to survive and more likely to die and won’t be able to pass on their genes to the next generation. (1)

Over time there will be more individuals with beneficial characteristics compared to those that haven’t, the species will evolve to have beneficial characteristics. (1)

1) Where would you find the DNA in a cell? (1 mark)

2) Where would you find a gene (1 mark) 3) How many chromosomes are there in the nucleus in an animal cell? (1 mark)

4) How many pairs of chromosomes are there in the nucleus of an animal cell? (1 mark) 5) What is the definition of the term allele? Give an example. (2marks)

6) What do we mean by a dominant trait and a recessive trait? (2 marks)

7) Alleles are represented with letters. How do we represent the dominant allele and the recessive allele? (2 marks)

8) What do we mean by the terms homozygous and heterozygous? (2 marks)

9) What do we mean by the term genotype and phenotype? Give examples (2+2 marks)

10) Describe the following genotypes – e.g. HH = homozygous dominant (3 marks) a) Bb – b) BB - c) bb –

Genes

11) What must the genotype be if the recessive trait is going to show through? Explain your answer (2 marks)

12) Carry out a pedigree analysis for a cross between the following genotypes Bb and bb (2 marks)

13) B codes for brown eyes and b codes for blue eyes. What is the probability that the offspring of the cross above will have blue eyes? Represent as a ratio and a percentage and a chance out of 4 (2 marks)

14) If D codes for dark moths and d codes for white moths. What is the probability of white moths being produced if you had a heterozygous female with a homozygous recessive female? (4 marks)

15a) What is sickle cell disease? (1 mark) b) What is cystic fibrosis? (1 mark)

16a) Name 2 symptoms of sickle cell disease and explain what causes these. (4 marks)

b) Name 2 symptoms of cystic fibrosis and explain what has causes these. (4 marks)

17) Why is it that someone with sickle cell disease is protected against malaria? (1)

18) If two carriers of sickle cell disease had children, what would be the likelihood of them producing a Normal child (non sufferer), a carrier or an affected child? (4 marks)

19) Why do people use a pedigree analysis? (1 marks)

The pedigree anlaysis above shows the inheritance of cystic fibrosis.

20a) Look at the pedigree above. What is the genotype of Brian? How do you know? (2 marks)

b) What are the chances of Sam being a carrier of cystic fibrosis? (4 marks)

1) Where would you find the DNA in a cell? (1 mark)

In the nucleus

2) Where would you find a gene (1 mark) On the chromosome in the nucleus3) How many chromosomes are there in the nucleus in an animal cell? (1 mark) 46 pairs4) How many pairs of chromosomes are there in the nucleus of an animal cell? (1 mark) 23 pairs5) What is the definition of the term allele? Give an example. (2marks)

Different versions/form of the same gene (1), E.g. Allele for the brown eye characteristic or blue eye characteristic (1)

6) What do we mean by a dominant trait and a recessive trait? (2 marks)

Note: Everyone will have 2 alleles for every characteristic in the body, one from mum and one from dad. There is a random cehance of the trait that your parents will pass on, they won’t always pass the dominant allele to you but if they pass you a dominant trait then that will show inside you.

Dominant – the trait/characteristic that will show through (1) Recessive – the weaker trait that will not show through if it is passed onto you

alongside a dominant trait. (1)

7) Alleles are represented with letters. How do we represent the dominant allele and the recessive allele? (2 marks)

First letter of the dominant characteristic with a capitol letter (1) First letter of the dominant characteristic but this time with a lower case letter

(1)

8) What do we mean by the terms homozygous and heterozygous? (2 marks) Homozygous – 2 alleles that are the same Heterozygous – 2 alleles that are different

9) What do we mean by the term genotype and phenotype? Give examples (2+2 marks)

Genes answers

Genotype – the alleles that have been inherited (1) e.g. Bb or CC or ff (1) Phenotype – the physical characteristic that shows through (1) e.g. Blue eyes,

brown eyes, cystic fibrosis, sickle cell trait, (1)

10) Describe the following genotypes – e.g. HH = homozygous dominant (3 marks) a) Bb – Heterozygous b) BB – homozygous dominant c) bb – homozygous recessive

11) What must the genotype be if the recessive trait is going to show through? Explain your answer (2 marks) Homozygous recessive (1) 2 recessive alleles are needed for the characteristic to come through, if a dominant allele is passed on then it would show through rather than the recessive allele(1)

12) Carry out a pedigree analysis for a cross between the following genotypes Bb and bb (2 marks)1 mark for correct genotypes in the correct box (boxes 1-4 all correct1 mark for correct offspring (boxes 5-8 all correct)

B (1)

b (2)

b (3)

Bb (5)

bb (6)

b (4)

Bb (7)

bb (8)

13) B codes for brown eyes and b codes for blue eyes. What is the probability that the offspring of the cross above will have blue eyes? Represent as a ratio and a percentage and a chance out of 4 (2 marks)Probability: 50% blue eyes or 2/4 chanceRatio: 2: 2 Blue: Brown

14). If D codes for dark moths and d codes for white moths. What is the probability of white moths being produced if you had a heterozygous female with a homozygous recessive female? (4 marks)Note: 1 mark each for correct gametes, boxes 1&2 then 3&4. 1 for correct offspring, 1 for correct probability

D d Probability: 50% or 2/4

(1) (2) d (3)

Dd (5)

dd (6)

d (4)

Dd (7)

dd (8)

15a What is sickle cell disease? (1 mark) When the haemoglobin in the red blood cell becomes sickle shaped (1)

b What is cystic fibrosis? (1 mark) Genetic disorder of the cell membrane, body produces a lot of thick sticky mucus from air passages, gut, ducts and pancreas (1)

16a Name 2 symptoms of sickle cell disease and explain what causes these. (4 marks)Note: Sufferers of sickle cell disease do not have difficulties with breathing, only difficulties with delivering oxygen.

Tiredness (1) – caused by lack of oxygen being delivered to cells (1) (due to the sickle cell red blood cells being stuck in the capiliiaries).

Painful joints and muscles (1) - When sickle cells become stuck in the capillaries (1)

16b. Name 2 symptoms of cystic fibrosis and explain what has causes these. (4 marks) Breathing difficulties (1), caused by production of thick sticky mucus in air

passages (1) Lung infections (1), caused by thick mucus that has trapped bacteria not being

able to move along the air passage and out of the body or into the stomach (1) Malnutrition (2) – enzymes can’t work as sticky mucus blocks the ducts where

organs release enzymes so food isn’t broken down. Fertility problems (1) – thick sticky mucus blocking reproductive ducts 17. Why is it that someone with sickle cell disease is protected against malaria? (1) The malaria parasite cannot live on sickle shaped cells (1)

18. If two carriers of sickle cell disease had children, what would be the likelihood of them producing a Normal child (non sufferer), a carrier or an affected child? (4 marks)Note: 1 mark each for correct gametes, one for correct offspring, 1 mark for correct presentation of probability or ratio’s

S s Probability: Carrier: Sufferer: Normal non affected

2 : 1 : 1

(1) (2) S (3)

SS (5)

Ss (6)

s (4)

Ss (7)

ss (8)

19. Why do people use a pedigree analysis? (1 marks) To work out the probability that they might have a child that would have a particular genetic disorder

The pedigree anlaysis above shows the inheritance of cystic fibrosis.

20a. Look at the pedigree above. What is the genotype of Brian? How do you know? (2 marks) Homozygous recessive cc (1) Brian is affected by cystic fibrosis, this means that he must have Inherited both recessive alleles

20b. What are the chances of Sam being a carrier of cystic fibrosis? (4 marks)

C (1)

c (2)

c (3)

Cc (5)

cc (6)

c (4)

Cc (7)

cc (8)

Probability: Carrier: Sufferer: Normal non affected

2 : 2 : 0

50% chance of being a carrier.

1) What is homeostasis? (1 mark)

2) Which part of the brain controls homeostasis? (1 mark) 3) What do the following terms mean? A – Thermoregulation, B - Osmoregulation (1 mark)

Homeostasis and nerves /53

4) Why is homeostasis a negative feedback system? (2 mark)

5) a. Which biological substances need to work at 37⁰ in the body? (1 mark) b. what happens to these if the body becomes too warm or too cold? (2 marks)

Warm - Cold –

6) Does sweat help to cool the body down or warm the body up? Explain how? (4 marks)

7) How does the hair help to keep the body warm? (3 marks)

8) How does shivering help to warm the body? (2 marks)

9) What do we mean by vasodilatation? How does this help to cool the body? (3 marks)

10) What do we mean by vasoconstriction? How does this help to cool the body? (3 marks)

11) What is the role of the sebaceous gland? (2 marks)

12) Why do we have nerve endings in the skin?

(1mark )

13) What does the central nervous system consist of? (1 mark)

14) Name the 3 different types of nerves and their roles in the body (3 marks)

15) Describe the pathway involved when the nervous system coordinates a response (6 marks)

16) Describe the pathway of an uncoordinated response (reflex arc) (6 marks)

17) What is the role of the myelin sheath on a neurone? (3 marks)

18) A synapse can be found between the relay neurone and sensory and motor nerves. Describe how the impulse travels across a neurone.

(4 marks)

19) Compare the transmission of an impulse (how the impulse is carried) along an axon with transmission across a synapse

(2 marks)

20) Why is it an advantage for the axon to be long? (2 marks)

1) What is homeostasis? (1 mark)

Maintaining a stable internal environment. Or, keeping the internal body environment the same (1)

2) Which part of the brain controls homeostasis? (1 mark) The hypothalamusNote : It contains receptors that can sense the blood temperature

3) What do the following terms mean? A – Thermoregulation, B - Osmoregulation (1 mark) A – Maintaining a constant internal temperature, B – Regulating internal water content

4) Why is homeostasis a negative feedback system? (2 mark)

The body detects a change (1), the body then reacts to have the opposite change (1). Note : If the internal body environment changed too much then it might not be possible to change it back.

5) i. Which biological substances need to work at 37⁰ in the body? Enzymes (1 mark) ii. What happens to these if the body becomes too warm or too cold? (2 marks)

Warm – They denature (break down) and cannot carry out chemical reactions in the body (1)

Cold – They slowdown and therefore cannot carry out the chemical reactions in the body, they need to be warmed up to 37⁰ in order to work (1)

6) Does sweat help to cool the body down or warm the body up? Explain how? (4 marks)Note : If you are asked to explain how the body cools down, always say how energy is transferred out of the body

Homeostasis and nerves answer sheet /53

Sweat glands produce sweat to cool the body down (1) Sweat evaporates (1) Heat transfers from the body to the environment (1) When the liquid turns to a gas (1)

7) How does the hair help to keep the body warm? (3 marks)

Hair erector muscle contracts (1), hair stands on end (1), they trap a layer of air which insulates the body (1).

8) How does shivering help to warm the body? (2 marks) When the body shivers the muscles respire (1), cells release heat when they

respire, the body warms up (1)

9) What do we mean by vasodilatation? How does this help to cool the body? (3 marks) Blood vessels dilate (1), blood travels to the surface of the skin (1), heat radiates

away from the body (1) Note: for higher level, say that the shunt vessel closes to

redirect the blood so that it flows nearer the surface of the skin.

10) What do we mean by vasoconstriction? How does this help to cool the body? (3 marks) Blood vessels constrict (1), less blood travels to the surface of the skin (1), less heat radiates out of the body (1)

Note: for higher level, say that the shunt vessel opens to redirect the blood so that less blood flows to the surface of the skin, blood flows closer to the vital organs

11) What is the role of the sebaceous gland? (2 marks) Produces oil (1), to moisturise the skin (1)

Shunt vessel has closed.

Shunt vessel has opened

12) Why do we have nerve endings in the skin? (1mark )

To sense temperature and pain (1)

13) What does the central nervous system consist of? (1 mark) Brain and spinal cord.

14) Name the 3 different types of nerves and their roles in the body (3 marks) Sensory nerve – sends information from the receptor to the brain (1) Motor nerve - sends information from the brain to the effector (muscles) (1) Relay nerve – connects sensory nerves to motor nerves (1)

15). Describe the pathway involved when the nervous system coordinates a response (6 marks)

• Stimulus – receptor – sensory nerve – brain- motor nerve – effector (muscle) – response

16) Describe the pathway of an uncoordinated response (reflex arc) (6 marks)

• Stimulus – receptor – sensory nerve – RELAY NERVE- motor nerve – effector (muscle) – response

17) What is the role of the myelin sheath on a neurone? (3 marks)

Note: Do not say that it protects the neurone, you will not receive marks for this response. Electrical insulator (1), speeds up the electrical impulse (1), Stops the impulse getting lost.

18) A synapse can be found between the relay neurone and sensory and motor nerves. Describe how the impulse travels across a neurone.

(4 marks) Presynaptic cell releases neurotransmitters (1), neurotransmitters diffuse across the synapse (1), the neurotransmitters bind to receptors on the post synaptic cell (1), an electrical impulse is triggered on the next neurone (1).

19) Compare the transmission of an impulse (how the impulse is carried) along an axon with transmission across a synapse

(2 marks) Axon – electrical impulse (1) Synapse – chemical impulse (1)

20) Why is it an advantage for the axon to be long? (2 marks) Speeds up the impulse Note: When one neurone connects with another impulses are slowed down, one long neurone is much quicker than lot’s of short ones joined together.

1) What is homeostasis? (1 mark)

2) Which method of sending signals around the body is slower? Hormones or nerves? (1 mark)

3) What are hormones? How do they travel through the body? (2 mark)

4) What do we call an organ that produces hormones? (1 mark)

5) What do we call the cells (or the organ) that these hormones will affect? (1 mark)

6) What do these cells have on them that will respond to the hormones? (1 marks

7) Compare the actions of nerves to the actions of hormones (4 marks)

8) Which food group will put glucose into the blood? Give an example (2 marks)

9) Which hormones are involved in glucose regulation? When will each be released (when glucose levels in the blood are high or when glucose levels are low in the blood?) (2 marks)

Homeostasis and hormones /55

10) Which endocrine gland produces these hormones? (1 marks)

11) Which organ or cells have the receptors that will respond to this endocrine gland? (1 mark)

12a) What substance in glucose stored as in the liver? (1 mark) b) What substance is glycogen broken down into? (1 mark)

13) How will the body regulate glucose levels once someone has eaten a meal? (5 marks)

14) How will the body regulate glucose levels once someone has exercised? (5 marks)

15) What causes type 1 and type 2 diabetes? (2 mark )

16) How do you treat or control the 2 types of insulin? (4 mark)

17) What do we mean by a phototropism, gravitropism. (2 marks)

18) How do auxins effect a) the shoot of a plant), b) the root of a plant? (4 +4 marks)

19) What effect does the hormone giberellin have on the plant? (2 marks)

20) Name and explain the 4 ways in which plant hormones are used commercially (8 mark)

1) What is homeostasis? (1 mark)

Maintaining a stable internal environment. Or, keeping the internal body environment the same (1)

2) Which method of sending signals around the body is slower? Hormones or nerves? (1 mark) Hormones

3) What are hormones? How do they travel through the body? (2 mark)

A chemical messenger (1) that travels in the blood (1)

4) What do we call an organ that produces hormones? (1 mark) Endocrine gland.

Homeostasis and hormones /55

5) What do we call the cells (or the organ) that these hormones will affect? (1 mark) Target organs or target cells.

6) What do these cells have on them that will respond to the hormones? (1 marks Receptors that can respond to the hormones

7) Compare the actions of nerves to the actions of hormones (4 marks) Note: need the full comparison needed for each mark

Nerves act fast , hormones act slow (1) Nerves act for a short period of time, hormones act for a long period of time

(1) Nerves act on a precise area, hormones act in a more general way (1) Nerves carry an electrical signal, hormones are a chemical messenger (1)

(Note, do not refer to impulses or signals as a message, even if it says this in your revision guide).

8) Which food group will put glucose into the blood? Give an example (2 marks) Carbohydrates (1). Bread, potatoes, pasta, rice (1)

9) Which hormones are involved in glucose regulation? When will each be released (when glucose levels in the blood are high or when glucose levels are low in the blood?) (2 marks) Insulin, when glucose levels in the blood are high (1) Glucagon, when glucose levels in the blood are low (1) Hint: Glucagon is released when glucose levels in the blood are gone

10) Which endocrine gland produces these hormones? (1 marks) Pancreas Hint: Remember “Pee Pee” – Pancreas produces

11) Which organ or cells have the receptors that will respond to this endocrine gland? (1 mark) Liver organ, liver cells12a) What substance in glucose stored as in the liver? (1 mark) b) What substance is glycogen broken down into? (1 mark) a) Glycogen b) Glucose

13) How will the body regulate glucose levels once someone has eaten a meal? (5 marks)

Note: Any 5 of the following . For a 6 mark extended answer you would need them all. Glucose levels in the blood will rise (1), pancreas releases (1) insulin (1), the liver responds to the insulin (1). Glucose is taken out of the blood (1), and stored in the liver as glycogen (1), glucose levels return back to normal (1) 14) How will the body regulate glucose levels once someone has exercised? (5 marks) Note: Any 5 of the following . For a 6 mark extended answer you would need them all. Glucose levels in the blood will fall (1), pancreas releases (1) glucagon (1), the liver responds to the glucagon (1), glycogen is converted to glucose (1) and absorbed back into the blood (1). Glucose levels return back to normal (1)

15) What causes type 1 and type 2 diabetes? (2 mark ) Type 1 diabetes – pancreas produces no insulin Type 2 diabetes – liver doesn’t respond to the insulin that is produced

16) How do you treat or control the 2 types of insulin? (4 mark) Type 1 – Avoid foods that are rich in carbohydrates (1), eat a healthy diet, inject insulin into fat layer of body cells (1). Type 2- Eat a healthy diet (1), partake in regular exercise (1),

17) What do we mean by a phototropism, gravitropism. (2 marks) Phototropism – the growth of a plant in response to light (1). Shoots are positively phototrophic as they grow towards the light. Gravitropism – The growth of a plant in response to gravity (1), roots are positively gravitrophic, grow towards the ground.

18) How do auxins effect a) the shoot of a plant), b) the root of a plant? (4 +4 marks) a) Shoot – Auxin is produced in the tip (1), auxin diffuses away from the light source (1), this causes the cells behind the tip to elongate (1), the shoot grows towards the light for photosynthesis (1) b) Root – when a root is flat the auxin is distributed along the bottom of the root (1), the auxin inhibits the growth on the lower side of the root (1). The cells on the top start to elongate faster (1), the root grows towards the ground (1)

19) What effect does the hormone giberellin have on the plant? (2 marks) Helps with seed germination, stem growth and flowering (1), helps stems to elongate (1) and helps them to grow tall (1)

20) Name and explain the 4 ways in which plant hormones are use commercially (8 mark) 1) As selective weed killers (1), – Weeds have broad leaves, weed killers effect broad leaved plants (1) 2) Growing plants from cuttings using rooting powder (1), rooting powder contains growth hormones that help roots to grow if a cutting of a plant is dipped into it. 3) Controlling the ripening of fruit (1), either whilst on the plant or during transport. Ripening hormone will ripen on the way to the supermarket if it is sprayed with growth hormone. 4) Producing seedless fruit (1), growth hormone will be added to unpollinated flowers, it will think it has been pollinated and the fruit will grow, without the seeds (seeds only grow when plants have been pollinated).

1) What is a drug (1 mark)

2) Name 2 useful drugs and 2 harmful drugs (2 mark)

3) What do we mean when we say that drugs are addictive? (2 mark)

4) What do we mean by tolerance? (1 mark)

5) Give an example of a depressant and explain what effect it has on the body (2 marks)

6) Give an example of a stimulant and explain what effect it has on the body (2 marks)

Drugs and disease /48

7) Give an example of a painkiller and explain what effect it has on the body (2 marks)

8) Give an example of a hallucinogen and explain what effect it has on the body (2 marks)

9) What is a reaction time? (1)

10) What effect does smoking tobacco have on the body? (3 marks)

11) Name some short term and long term effects of alcohol on the body (2 marks)

12) Some people are less likely to get an organ transplant than others. In what situations would a person be less likely? (4 marks) 13) Some people are less likely to get an organ transplant than others. In what situations would a person be less likely? (4 marks)

14) What is a pathogen? Name 4 (2 marks)

15) Find out how each of the diseases below are transmitted (with how they are spread) (4 marks) - Cholera – Athletes foot - Influenza – Malaria -

16) We have physical barriers to stop pathogens entering the body. Name and explain them (2 marks)

17) We also have chemical barriers to stop pathogens from entering the body. Name and explain them (2 marks)

18) What is the difference between antiseptics and antibiotics? Give examples (2 marks)

19) Outline the 6 steps to show how bacteria can become resistant to antibiotics (6 marks)

20) You can conduct a practical experiment to investigate antibiotics and antiseptics. You can grow cultures of micro-organisms to investigate. Explain what an inhibition zone is. (3 marks )

1) What is a drug (1 mark)

Chemical substances that affect the central nervous system and cause changes in psychological behaviour.

2) Name 2 useful drugs and 2 harmful drugs (2 mark) Antibiotics and penicillin

3) What do we mean when we say that drugs are addictive? (2 mark)

People have a physical need for the drug, they get withdrawal symptoms if they don’t take them.

4) What do we mean by tolerance? (1 mark) When the body gets used to having it and you need a higher dose for it to have the same effect.

5) Give an example of a depressant and explain what effect it has on the body (2 marks) Alcohol (1) decrease the activity in the brain. Slow down the responses of the nervous system

6) Give an example of a stimulant and explain what effect it has on the body (2 marks) Nicotine/Caffeine (1). Increase activity in the brain. Increase neurotransmitter at the synapse, speeds up reactions.

7) Give an example of a painkiller and explain what effect it has on the body (2 marks) Narcotics/ morphine. Decrease the feeling of pain. Blocks the nerve impulses in the brain

8) Give an example of a hallucinogens and explain what effect it has on the body (2 marks) LSD, distorts what’s seen and heard by altering the pathways.

9) What is a reaction time? (1)

Drugs and disease /48

Time it takes the body to respond to a stimulus

10) What effect does smoking tobacco have on the body? (3 marks)

Tobacco smoke contains carbon monoxide, this combines with the haemoglobin in the blood, blood carries less oxygen.

Tobacco smoke contains carcinogens such as tar Smoking tobacco is addictive.

11) Name some short term and long term effects of alcohol on the body (2 marks) Short term – slows down reactions, depressant, blurred vision – 1 mark for any of these Long term – poisonous, death of liver cells if it is overworked when breaking down alcohol, cirrhosis of the liver (scarring of liver tissue). Brain damage – 1 mark for any of these12) Some people are less likely to get an organ transplant than others. In what situations would a person be less likely? (4 marks) If they are obese (1) people who have damaged their liver through drinking (1), if they are too far away from the donor (1) if there is a large age difference between donor and recipient (1). 13) Some people are less likely to get an organ transplant than others. In what situations would a person be less likely? (4 marks) If they are obese (1) people who have damaged their liver through drinking (1), if they are too far away from the donor (1) if there is a large age difference between donor and recipient (1).

14) What is a pathogen? Name 4 (2 marks) Disease causing microbe (1), eg fungi, bacteria, viruses, protozoa

15) Find out how each of the diseases below are transmitted (with how they are spread) (4 marks) - Cholera – Water, Athletes foot - contact Influenza – Air Malaria - Vector

16) We have physical barriers to stop pathogens entering the body. Name and explain them (2 marks) Undamaged Skin (1) – If damage the blood clots quickly Respiratory system – (1) the trachea and lungs are lined with mucus and cilia. The mucus traps the dust, the cilia push the mucus away from the lungs out of the mouth or towards the stomach.

17) We also have chemical barriers to stop pathogens from entering the body. Name and explain them a) Tears – contains lysozymes which kill bacteria b) Stomach acid – hydrochloric acid kills pathogens inside the body. (2 marks)

18) What is the difference between antiseptics and antibiotics? Give examples (2 marks) Antiseptics – use outside the body to stop diseases growing and spreading e.g. household products Antibiotics – used inside the body to treat infections e.g. antibacterial and antifungals

19) Outline the 6 steps to show how bacteria can become resistant to antibiotics (6 marks)

Bacteria can mutate, sometimes this makes them resistant to antibiotics When you treat an infection, if some bacteria are resistant then they won’t

be killed by antibiotics This means that the non resistant strains of bacteria will be killed. The resistant will survive and reproduce The resistant strain can cause serious infection. In hospitals, bacteria are spread quickly, they are more likely to spread,

reproduce and become resistance

20) You can conduct a practical experiment to investigate antibiotics and antiseptics. You can grow cultures of micro-organisms to investigate. Explain what an inhibition zone is. (3 marks )

When bacteria is grown in a petri dish, you can put different antibiotics on the dish (1). The antibiotic should clear a ring around the bacteria (1). You can measure the size of this ring to work out which is the best antibiotic by measuring the size of the inhibition zone)

1) Name the type of organism that is found at the start of most food chains. (1 mark)

Interdependence /53

2) What does a pyramid of biomass show? (1 mark)

3) State two ways in which energy can be lost between organisms in a food chain (trophic levels) e.g. between a rabbit and fox in a food chain.

(2 marks)

4) Suggest how a farmer rearing chickens could limit energy loss from the chickens. (2 marks)

5) Tubeworms rely on bacteria to gain the correct amount of nutrition. The bacteria also rely on the tubeworms to survive. What is the name given to this type of relationship?

(1 mark)

6) Describe 3 other mutalistic relationships (3 marks) Note in an exam say how each organism benefits from the relationship.

7) Describe 4 parasitic relationships (4 marks) Note say how the parasite benefits and the host suffers.

.

8) The human population is increasing. Why is this a potential problem (3 marks)

9) What do we call the build-up of nutrients such as nitrates and phosphates in an aquatic (water) environment? (1 mark)

10) Suggest how farming can lead to a build-up of nutrients such as nitrates and phosphates in a lake and then lead to the death of aquatic life. (8 marks)

11) What are the problems associated with re-cycling? (5 marks)

12) What indicator species would you use to test for air pollution in the environment, say what you would look for (2 marks)

13) Explain how the quality of a river can be monitored by studying the organisms present in the water, hint, there are 2. (4 marks)

14) Name the processes that put carbon back into the atmosphere. (1 mark)

15) Name the processes that take carbon from the atmosphere? (1 mark)

16) Explain how carbon is cycled in nature. (6 marks)

17) Explain how composting increases carbon dioxide concentration in the air. (2 marks)

18) Explain why nitrates are important for plants. (1 mark)

19) Name one type of bacteria that takes nitrates out of the soil (1 mark)

20) Name each type of bacteria involved in the nitrogen cycle and explain their role in the cycling of nitrogen.

(4 marks)

1. Name the type of organism that is found at the start of most food chains. (1 mark)

Producer (1)

2. What does a pyramid of biomass show? (1 mark) The amount of energy available at each level of the food chain (1)

3. State two ways in which energy can be lost between organisms in a food chain (trophic levels) e.g. between a rabbit and fox in a food chain.

(2 marks) Any 2 from heat, respiration, movement, excretion.

4. Suggest how a farmer rearing chickens could limit energy loss from the chickens. (2 marks)

Keep them in a small pen to limit movement. (1) Keep them warm so no energy is lost keeping warm (1)

5. Tubeworms rely on bacteria to gain the correct amount of nutrition. The bacteria also rely on the tubeworms to survive. What is the name given to this type of relationship?

(1 mark) Mutualism / symbiosis (1)

6. Describe 3 other mutalistic relationships (3 marks) Note in an exam say how each organism benefits from the relationship.

Oxpeckers ( will eat pests and alert the animal to predators) and buffalo (provide oxpeckers with a source of food) (1)

Cleaner fish (eat dead skin and parasites) and larger fish (provide a source of food and help the cleaner fish to avoid being eaten).

Nitrogen fixing bacteria (provide plants with nitrates), and plants (provide bacteria with a constant supply of nutrients (1).

7. Describe 4 parasitic relationships (4 marks) Note say how the parasite benefits and the host suffers.

Fleas and animals. Fleas feed by sucking the blood of their hosts, host has bites (1) Head lice and human scalps. Headlice suck blood for food, host will then itch (1) Tapeworms and humans – attach to intestinal wall using hooks or suckers and will

absorb nutrients from the host. Host becomes malnourished (1) Mistletoe and trees – Mistletoe absorbs the nutrients from the host, the host e.g tree

reduces in growth due to lack of nutrients.

8. The human population is increasing. Why is this a potential problem (3 marks)

Raw materials/non renewable resources are running out (1) More waste is being produced (1) More pollutants such as phosphates from detergents, nitrates from fertilisers and

sulphur dioxide from power stations are being produced. (1)

Interdependence /53

9. What do we call the build-up of nutrients such as nitrates and phosphates in an aquatic (water) environment? Eutrophication. (1) (1 mark)

10. Suggest how farming can lead to a build-up of nutrients such as nitrates and phosphates in a lake and then lead to the death of aquatic life. (8 marks)

Farmers spray excess fertiliser onto crops, These are washed into nearby lakes when it rains, we call this leeching. The nitrate / phosphate fertiliser makes algae grow out of control, covering the

surface of the lake Algae block the light from reaching plants in the water. Plants can no longer photosynthesis and die. Bacteria break down the dead plants. The bacteria remove oxygen from the water for respiration. The oxygen levels decrease in the water so fish etc cannot respire, fish die.

11. What are the problems associated with re-cycling? (5 marks)

Recycling uses energy which is costly Some waste materials are time consuming to sort out. Equipment needed to recycle is expensive Quality of recycled material isn’t good Some materials can only be recycled a certain number of times

12. What indicator species would you use to test for air pollution in the environment, say what you would look for blackspot fungus shows clean air as it is killed by sulphur dioxide (1) lichen, air is clean if there is lots of lichen (1)

13. Explain how the quality of a river can be monitored by studying the organisms present in the water, hint, there are 2. (4 marks)

If you find stonefly larva or freshwater shrimp (1) this indicates low levels of pollution and plenty of oxygen (1)

If you sludgeworm or bloodworms (1) this indicates low oxygen levels and the water could be polluted – possibly eutrophication is occurring (1)

14. Name the processes that put carbon back into the atmosphere. (1 mark)

Respiration, combustion,

15. Name the processes that take carbon from the atmosphere? (1 mark)

Photosynthesis, dissolving into oceans

16. Explain how carbon is cycled in nature. (6 marks)

Plants take carbon dioxide in during photosynthesis, Plants release carbon dioxide into the atmosphere during respiration (as do animals

and bacteria). Plants use the carbon dioxide to make glucose which is then eaten by animals. Animals release waste or die which are them broken down by decomposers which

respire and put CO2 back into the atmosphere. Some plants and animals, over millions of years become fossil fuels which are the

burned. Combustion releases the CO 2 back into the atmosphere.

(2 marks)

17. Explain how composting increases carbon dioxide concentration in the air. (2 marks)

Bacteria break down waste material (1), releasing CO2 into the atmosphere through respiration (1)

18. Explain why nitrates are important for plants. (1 mark) Nitrates are used by plants to make proteins and used for growth

19. Name one type of bacteria that takes nitrates out of the soil (1 mark)

Denitrifying bacteria.

20. Name each type of bacteria involved in the nitrogen cycle and explain their role in the cycling of nitrogen.

(4 marks)

Nitrogen fixing bacteria: - Converts nitrogen straight into nitrates / ammonia for the plant to use (1)

Decomposer bacteria - Break down dead animals and plants and also waste into ammonia (1)

Nitrifying bacteria - Convert the ammonia in the soil into nitrites then nitrates for plants to take into their roots (1)Denitrifying bacteria: Convert nitrates in waterlogged soil into nitrogen gas and put it back into the atmosphere (1)

B1 exam: Key words to understand

There are lots of new key terms that you need to make sure you understand in preparation for your exam. It’s really important that you recognise what each of the words mean and are able to use them correctly in a sentence. This will help you to explain ideas scientifically and ensure you pick up important marks in your exam.

Some tips for learning science vocabulary.

Tip 1 -Play some games with the keywords

You could play hangman with your friends or family using the words you need to learn. Make sure you explain what the word means when they have guessed it.

You could play Pictionary for some of the energy types or renewable energy sources. Ask someone to draw you a picture for one of these terms and see if you can guess which one they are drawing.

Tip 2 – Use flash cards

Write out the key word and the definition on separate cards, mix them up and see if you can match the keyword with the correct description.

Write the keyword on one side and the definition on the other. Look at the keyword side and see if you can remember the definition or read the definition and try to remember the keyword. Turn the card over to check, or ask someone else to read them out to you.

See if you can sort the keywords into groups of similar words. For example, you could group together all the words that give a different type of energy. Try to explain why you have grouped them together to a friend or family member.

Tip 3 – Spelling strategies

Use the spelling strategies that you talk about in tutor time to help with any words that you find difficult to spell.

Break it into sounds (d-i-a-r-y)Break it into syllables (re-mem-ber, con-tin-ent)Break it into word parts (dis+satisfy)Use a mnemonic (necessary—one collar, two sleeves, rhythm has your

two hips moving)Refer to word in the same family (muscle—muscular)Say it as it sounds (Wed-nes-day)Words within words (Parliament—I AM parliament, GUM in argument)Make connections between words (bright, light, night, etc)Think about the meaning of words (bi+cycle = two+wheels)Apply spelling rules (writing, written)Learn by sight (look—cover—write—check)

Classification and Genes

Key term What it meansKingdom The highest level used to classify organisms

Unicellular Single-celled organismMulticellular Organism made of many cells

Nucleus Contains the chromosomes, which carry genes to control the activities of a cellAutotrophic Makes its own food (i.e. plants)

Heterotrophic Feeds by eating and digesting other organisms (i.e. animals)Saprophytic Feed by digesting organisms outside of the body (i.e. fungi)

Virus A microorganism that doesn’t fit into a kingdom as scientists don’t think of them as being alive.Chordata The phylum to which all vertebrates belong

Invertebrates Animals that do not have a backboneOviparous Lays eggsViviparous Gives birth to live young

Homeotherms Control their own body temperaturePoikilotherms Body temperature varies with the surroundings

Internal fertilisation The sperm and egg fuse inside the bodyExternal fertilisation The sperm and egg are released into the water before fertilisation occurs

Fertile Able to reproduceSpecies A group of organisms that can interbreed and produce fertile offspring

Hybrids Produced when two closely related species reproduce. Hybrids are not one species or the other but have characteristics of both. They are usually infertile.

Ring species Neighbouring populations of the same species that have slightly different characteristics but still interbreed to form a chain. The two species at either end of the chain cannot interbreed.

Binomial system The way an organisms is named using their Genus and species.Adaptations A change to help something carry out its job

Variation Differences in characteristicsBiodiversity A measure of the total number of different species in an area

Discontinuous variation Has a fixed set of values (no range). Data is represented as a bar chart.

Continuous variation The values can be any number within a certain range (a scale). Data is represented as a histogram or line graph.

Hydrothermal vents Habitats deep in the sea which have high heat and pressure.

Normal distribution curve Often produced when we measure a characteristic with continuous variation, most individuals fit in the middles section with less at the extremes.

Competition Where individuals compete for resources like food and space.

Natural selection ‘Survival of the fittest’ Individuals that survive can breed and reproduce which means they pass their adaptations to the next generation.

Evolution A gradual change over time.Extinct When a species has died out.

Speciation When a new species is formedChromosomes Made of DNA and found in the nucleus of cells

Bases Make up DNA, there are 4 bases A, T, C and GGene A section of DNA

Mutation A change in the genetic code (DNA)Allele Different form of a gene

Phenotype A characteristic that you have i.e. blue eyesGenotype The pair of alleles that you have

Homozygous A pair of the same alleles (aa or AA)Gametes The sex cells, egg and sperm.Dominant When the allele is present its characteristic will be expressedRecessive Two copies of the allele are required for the characteristic to be expressed

Heterozygous When you have two different alleles (Aa)Carrier Someone who carries an allele for a genetic disease but doesn’t have the disease themselves

Punnett square A genetic diagram used to work out the probability of an offspring being produced by a genetic cross

Sickle cell disease A recessive genetic disorder which causes sickle shaped red blood cellsCystic fibrosis A recessive disease where the lungs get clogged with a thick mucus

Responding to change

Key term What it means

Pedigree analysis Doctors use pedigree charts to understand how a disorder is inherited and the probability that a person may have inherited the disorder from their parents

Homeostasis Keeping the body’s internal conditions constant or stable

Negative feedback A change to the body happens in one direction and mechanisms in the body work to make it change in the opposite direction

The reflex arc A chain of nerves that brings about a reflex responseOsmoregulation The control of water in your body

Hormones Chemical messengers that are used by the endocrine systemEndocrine glands Release hormonesThermoregulation The control of body temperature

Hypothalamus An area of the brain involved in thermoregulationErector muscles In the dermis of the skin contract to make the hair stand upright.Vasoconstriction When blood vessels narrow

Vasodilation When blood vessels widenSense organ Detects changes in the environment

Stimulus A change in the environment that your body is sensitive toReceptor cells Cells in the sense organ that detect a stimulus

Impulses Electrical signals sent by the nervous systemNeurones Nerve cells

Nerves Bundles of neuronesNeurotransmission The transmission of impulses along neurones

Dendrons Receive impulses from receptor cells or other neuronesDendrites Branches at the end of dendrons

Axon Carries impulses from the cell body to the brain or other neuronesInvoluntary response A response that you don’t have to think about

Central Nervous System (CNS) Brain and spinal cord

Voluntary response A response where you have to think about your actionSensory neurone Send impulses from receptors to the central nervous systemMotor neurone Send impulses from the central nervous system to effectorsRelay neurone Short neurones in the spinal cord that link motor and sensory neurones

Synapse Tiny gap that separates two neuronesNeurotransmitter Chemical substances used to transmit impulses through the gap between neurones

Myelin sheath A fatty layer surrounding the axon to insulate it and make messages travel fasterResponse What your body does in response to the stimulusEffector The muscle or organ that carries out the actionReflex Automatic responses that are extremely quick and protect the body.

Target organ An organ that responds to a certain hormoneInsulin A hormone produced by the pancreas to decrease the level of blood glucose

Glucagon A hormone produced by the pancreas to increase the level of blood glucoseGlycogen A store of glucoseDiabetes A disorder where people cannot control their blood glucose very well.

Subcutaneous fat The fat layer beneath the skin where insulin is injectedType 1 diabetes Where the pancreas does not produce insulinType 2 diabetes Cells in the body respond less well to insulin

Body Mass Index (BMI) How healthy a person’s mass is for their heightTropism Responding to a stimulus by growing towards or away from it

Phototropism A tropism caused by lightNegative tropism A tropism away from a stimulus

Auxin A plant hormone that causes positive phototropismGravitropism/Geotropism Growth towards the direction of gravity

Germinates Roots and shoots start to grow from a seedGibberellins A plant hormone that stimulates flower and fruit production

Drugs & Interdependence

Key term What it meansSelective weedkiller Contains auxin. Makes plants with broad leaves grow out of control and die.

Rooting powders Contains auxins. Makes roots develop quickly.Narcotic Drug that makes us feel sleepy

Hallucinogen Change the way the brain works causing hallucinationsStimulant Speeds up neurotransmission so speeds up reaction times

Depressants Slow down the activity of neurones in the brain so we relaxAddictive People become dependent on the drug

Carcinogen Chemical that causes cancerTar Found in cigarettes, contains carcinogens

Carbon monoxide Reduces the amount of oxygen that red blood cells can carryNicotine The addictive part of tobacco that makes it difficult to give upCirrhosis Liver disease where the normal tissue is destroyed

Physical barriers Stop pathogens entering the bodyChemical defences Kill pathogens before they can harm us

Antiseptics Chemical substances that kill microorganisms outside the bodyAntibiotics Kill or prevent the growth of bacteria and some fungi but not human cells

MRSA A bacterium resistant to many antibioticsInterdependent Organisms depend on each other

Biomass The mass of living thingsParasitism Feeding relationship where only one organism benefitsMutualism Feeding relationship where both organisms benefit

Nitrogen fixing bacteria Turn nitrogen in the air into nitrogen compoundsChemosynthetic bacteria Get their energy from chemical substances rather than light

Eutrophication Where fertiliser increases the concentration of nitrates and phosphates in water

KeyWords: Kingdoms, Chordata, vetebrates, invetebrates, bionomonal system,

Keywords:

B1 Topic 1 Classification, Variation and InheritanceThis topic looks at:General characteristics of animals and plantsProblems surrounding classificationAdaptations of organisms that can survive in extreme environmentsVariation, inheritance and Darwins theory of evolution

Describe the characteristics of organisms within the FIVE vertebrate kingdomsa)

b)

c)

d)

e)

State the 5 kingdoms and their characteristics used to classify ALL organismsa)

b)

c)

d)

e)

Why is classification important?

Classification of veterbratesWhat terms are used to describe vertebrates and what they mean

Identification KeyDraw an identification key for bat, dragonfly, eagle and fly.

Organisms have adapted to live in extreme environments, what are two examples of these?1.2.

Which species are hard to classify

Keywords: variation, continuous, discontinuous, genetic, environmental

Keywords: evolution, monohybrid inheritance

B1 Topic 1 Classification, Variation and InheritanceThis topic looks at:General characteristics of animals and plantsProblems surrounding classificationAdaptations of organisms that can survive in extreme environmentsVariation, inheritance and Darwins theory of evolution

Describe the 6 steps of Darwin's theory of evolution by natural selection

Variation in a species can be grouped into two typesExplain, give examples and draw a graph for each type of variation

What do these keywords mean?ChromosomeDNAGenesAllelesRecessiveDominantHeterozygoushomozygous PhenotypeGenotype

Genetic Variation Draw punnet squares or genetic cross diagrams1. Explain how brown eyes parents can have a blue eyed child

2. Show the phenotype and genotype for a cat heterozygous for colour and recessive for white. 3. Brown eyes are dominant over blue eyes. A homozygous dominant male mates with a heterozygous female

What factors cause variation?1.2.

Keywords: homeostasis, osmoregulation, thermoregulation,

Keywords: dendrons, myelin sheath, impulses, neurones, neurotransmitter

B1 Topic 2 Responses to a changing environmentThis topic looks at:How humans detect and respond to changes in their internal and external environmentsRole of hormones and the nervous systemRole of hormones in the plant system

Vasodilation and VasoconstrictionDraw and write how the body can control temperature using vasodilation and vasoconstriction

What is meant by homeostasis and give three examples

Nervous SystemWhat are the three parts of the nervous system

Neurones Explain what neurones are and draw the 3 types of nerve cells using arrows to show the direction in which the electrical impulse travels along each one.

SynapseDraw a synapse and explain how nerve impulses travel across this gap.

Nervous SystemWhat are the five senses

Keywords: reflex arc, reflex,

Keywords: diabetes, insulin, obesity, BMI (body mass index)

B1 Topic 2 Responses to a changing environmentThis topic looks at:How humans detect and respond to changes in their internal and external environmentsRole of hormones and the nervous systemRole of hormones in the plant system

Reflex arcs Explain what is happening using the following words stimulus, relay, motor, synapse, effectors

What two experiments could investigate involuntary responses in humans1.2.

What is meant by the terms voluntary and involuntary responses. Give an example of eachVoluntaryInvoluntary

Plant HormonesWhat are the two types of plant hormones and what do they do?

DiabetesDescribe how the body controls blood glucose levels when the concentration of blood glucose is too high. Draw a diagram to helpWhat is the difference between type I and II diabetesWhat are some symptoms of diabetes

Uses of Plant HormonesWhat are 4 commercial uses of plant

hormones.

Plant HormonesWhat are the two types of plant hormones and what do they do?

Keywords: drugs, medicines, painkiller, anti-inflammatory, opiates

Keywords: carbon monoxide, cancer, tar, nicotine, organs, tissues, ethical

B1 Topic 3 Problems of and solutions to a changing environmentThis topic looks at:How the body is affected by drugs and pathogensHow scientist have developed antibiotics and antisepticsHow man made chemicals pollute the environmentCarbon and nitrogen cycle

Describe the effects that smoking and alcohol have on the human body

Complete the table

Cannabis and OpiatesWhat are they and what are they used for?

TransplantsGive 3 organs that can be transplants and explain why it is a controversial issue

PathogensWhat is a pathogen? Draw or write the three types of pathogens

Draw or write how the effects of antibiotics and antiseptics can be investigated

Write or draw how different pathogens are spread within human populations

MRSAWhat are superbugs and how have they come about?

Nitrogen CycleDraw and label the nitrogen cycle

Animal DefencesAnimals and humans can defend themselves from pathogen attack explain howPhysical barriersChemical barriers

Keywords: vector, airborne, transmitted, indirect

Keywords: antibiotics, bacteria, fungi, penicillin, antibacterial, antifungals

B1 Topic 3 Problems of and solutions to a changing environmentThis topic looks at:How the body is affected by drugs and pathogensHow scientist have developed antibiotics and antisepticsHow man made chemicals pollute the environmentCarbon and nitrogen cycle