Environmental Environmental Biology Biology

and Geneticsand Genetics

Energy FlowEnergy Flow Ecology Ecology – The study of living organisms in – The study of living organisms in

relation to their environment relation to their environment OrganismOrganism – Living thing – Living thing HabitatHabitat – The place where an organism lives – The place where an organism lives PopulationPopulation – The total number of one type of – The total number of one type of

organism living in any one habitat organism living in any one habitat CommunityCommunity – The different populations of plants, – The different populations of plants,

animals and micro-organisms found in animals and micro-organisms found in a particular habitat a particular habitat

EcosystemEcosystem – A natural biological unit which is made – A natural biological unit which is made up of living and non-living parts up of living and non-living parts

All the energy in an ecosystem comes from the sunAll the energy in an ecosystem comes from the sun GreenGreen plants are able to convert plants are able to convert lightlight energy from the energy from the

sun into chemical energy (starch) during sun into chemical energy (starch) during photosynthesisphotosynthesis

GreenGreen plants are called producers because they are plants are called producers because they are able to produce their own foodable to produce their own food

Other organisms can not produce their own food, so Other organisms can not produce their own food, so must eat (consume) these plants and/or animalsmust eat (consume) these plants and/or animals

They are known as consumersThey are known as consumers

Three types of consumers;Three types of consumers; HerbivoresHerbivores - Eat - Eat onlyonly plant material plant material CarnivoresCarnivores - Eat - Eat onlyonly meat (animal) tissue meat (animal) tissue OmnivoresOmnivores - Eat - Eat bothboth plant and animal tissue plant and animal tissue

An animal that hunts another animal is called a An animal that hunts another animal is called a predatorpredator

The animal being hunted is the The animal being hunted is the preyprey DecomposersDecomposers are micro-organisms ie. Bacteria and are micro-organisms ie. Bacteria and

fungi, which get their energy from breaking down fungi, which get their energy from breaking down waste materialswaste materials

Now complete pages 1 and 2 of your sheetsNow complete pages 1 and 2 of your sheets. (Use pg 109 of the textbook to help). (Use pg 109 of the textbook to help)

Food Chains / WebsFood Chains / Webs When an animal eats a plant or animal energy is When an animal eats a plant or animal energy is

transferred from the food to the feedertransferred from the food to the feeder The animal that eats the plant at the start of a feeding The animal that eats the plant at the start of a feeding

relationship is called the primary consumer relationship is called the primary consumer (Normally a herbivore may be an omnivore)(Normally a herbivore may be an omnivore)

If the primary consumer is eaten by a second animal, If the primary consumer is eaten by a second animal, this second animal is called the secondary consumer this second animal is called the secondary consumer (may be an omnivore or a carnivore)(may be an omnivore or a carnivore)

Energy transfer continues the whole way along the Energy transfer continues the whole way along the feeding relationship. This is known as a feeding relationship. This is known as a food chain.food chain.

Food ChainsFood Chains A food chain always begins with a producer or A food chain always begins with a producer or

detritusdetritus Eg.Eg.

GrassGrass RabbitRabbit FoxFox (Producer) (Producer) (1st consumer) (1st consumer) (2nd consumer) (2nd consumer)

The arrows indicate the The arrows indicate the direction of energy direction of energy transfer.transfer.

Food WebsFood Webs In nature a food chain rarely occurs in isolationIn nature a food chain rarely occurs in isolation The producer may be eaten by a number of different animals, The producer may be eaten by a number of different animals,

which in turn may be preyed upon by many different predators which in turn may be preyed upon by many different predators (See pg 3 of sheets, pgs 110 – 112 of text )(See pg 3 of sheets, pgs 110 – 112 of text )

Food chains interconnect at many points to form a food webFood chains interconnect at many points to form a food web Look at the following food web and pick out at least 5 Look at the following food web and pick out at least 5

different food chains;different food chains;

EagleEagle FoxFox MerlinMerlin Skylark Skylark

Mountain HareMountain Hare GrouseGrouseMoth LarvaMoth Larva

HeatherHeather

Food WebsFood WebsPick out all the food chains from this web;Pick out all the food chains from this web;

FoxFoxOwlOwl

FrogFrog HedgehogHedgehogWeaselWeasel

SnailSnail VoleVole

RabbitRabbit

PrimrosePrimrose OakOak

Energy LossEnergy Loss Not all the energy available at each step of the food chain is passed on to the Not all the energy available at each step of the food chain is passed on to the

next step next step (See sheets pg 4)(See sheets pg 4) There is a significant energy loss at each step of a food chainThere is a significant energy loss at each step of a food chain

Energy Energy fromfromfoodfood100%100%

90% lost and is unavailable to other animals

10% is passed on to other animals (this energy is stored in the tissue of the plant or animal, until it is eaten)

Some energy not used

Some energy used

uneatenundigested Lost as

heatUsed for movement

Pyramid of NumbersPyramid of Numbers In most food chains there is a greater number of In most food chains there is a greater number of

producers than primary consumers, and a greater producers than primary consumers, and a greater number of primary consumers than secondary number of primary consumers than secondary consumers, and so onconsumers, and so on

The final consumer is least numerousThe final consumer is least numerous This numerical relationship is called a This numerical relationship is called a pyramid of pyramid of

numbers.numbers. As the organism higher in the food chain requires As the organism higher in the food chain requires

more food, the level before it in the pyramid is biggermore food, the level before it in the pyramid is bigger This is due to a decrease in energy being passed on.This is due to a decrease in energy being passed on.

Pyramid of NumbersPyramid of NumbersPrimrosePrimrose Snail Snail Hedgehog Hedgehog

Fox Fox DecreasingDecreasing DecreasingDecreasing numbersnumbers energy energy

FOXFOX

HEDGHOGHEDGHOG

SNAILSNAIL

PRIMROSEPRIMROSE

Pyramid of NumbersPyramid of Numbers In some food chains the In some food chains the

producer is a producer is a single single large plant and the large plant and the pyramid therefore takes pyramid therefore takes a different form.a different form.

Oak Tree Caterpillar Shrew OwlOak Tree Caterpillar Shrew Owl

OOTT

CaterpillarCaterpillar

ShrewShrew

OwlOwl

Pyramid of BiomassPyramid of Biomass The biomass of a population is its total mass of The biomass of a population is its total mass of

living matterliving matter The biomass at each level of the pyramid The biomass at each level of the pyramid

decreasesdecreases This can be represented as a This can be represented as a pyramid of pyramid of

biomassbiomass As there are so many organisms at each level As there are so many organisms at each level

of the pyramid, the weight decreases with the of the pyramid, the weight decreases with the numbers.numbers.

Pyramid of BiomassPyramid of BiomassPrimrosePrimrose Snail Snail Hedgehog Hedgehog

Fox Fox Decrease in biomassDecrease in biomass

FOXFOX

HEDGEHOGHEDGEHOG

SNAILSNAILPRIMROSEPRIMROSE

Pyramid of EnergyPyramid of Energy The most reliable The most reliable

comparison between comparison between organisms found at different organisms found at different levels of a food chain is in a levels of a food chain is in a pyramid of energypyramid of energy

This is based on This is based on productivityproductivity

This is measured as dry This is measured as dry mass per square metre per mass per square metre per year, before being converted year, before being converted into kilojoules per square into kilojoules per square metre per year.metre per year.

This type of pyramid will This type of pyramid will always take the shape of a always take the shape of a true pyramid, as only a true pyramid, as only a proportion of energy is proportion of energy is transferred from one level to transferred from one level to the next.the next. (Complete pgs 3-6 of sheets)(Complete pgs 3-6 of sheets)

Test your knowledge pgs 113 + 118 of textTest your knowledge pgs 113 + 118 of text Apply your knowledge pgs 119-122 of textApply your knowledge pgs 119-122 of text

FOXFOXHEDGHOGHEDGHOG

SNAILSNAIL

PRIMROSEPRIMROSE

Factors Affecting The Variety of Factors Affecting The Variety of Species in an EcosystemSpecies in an Ecosystem

SpeciesSpecies – A group of living organisms – A group of living organisms which are so similar to one which are so similar to one another that they are able to another that they are able to interbreed and produce fertile interbreed and produce fertile offspring offspring

BiodiversityBiodiversity Within an ecosystem there is a variety of habitatsWithin an ecosystem there is a variety of habitats Within each habitat there is a range of populations (plants, Within each habitat there is a range of populations (plants,

animals and micro-organisms)animals and micro-organisms) As well as being adapted to their habitat, each population is As well as being adapted to their habitat, each population is

adapted to a particular ecological niche in the pattern of the adapted to a particular ecological niche in the pattern of the communitycommunity

As an ecosystem develops over a period of time the range of As an ecosystem develops over a period of time the range of habitats and niches it contains increaseshabitats and niches it contains increases

This gives rise to a wide diversity of species in every This gives rise to a wide diversity of species in every ecosystemecosystem

An adaptation is an inherited characteristic that makes an An adaptation is an inherited characteristic that makes an organism well suited to survival in its environmentorganism well suited to survival in its environment

Some adaptations involve the structure of the organism’s Some adaptations involve the structure of the organism’s body, or a behavioural response to a particular environmental body, or a behavioural response to a particular environmental stimulistimuli

Adaptation can leave some species unable to cope with Adaptation can leave some species unable to cope with other/different habitats, environmental conditionsother/different habitats, environmental conditions

This means that some species will only be found in an area This means that some species will only be found in an area where the conditions are suitable to its survival needs, where the conditions are suitable to its survival needs, influencing its distribution in the ecosysteminfluencing its distribution in the ecosystem

A stable ecosystem contains a balance of interdependent A stable ecosystem contains a balance of interdependent producers, consumers and decomposers producers, consumers and decomposers

(Complete pgs 7 and 8 of sheets, use pgs 123-128 of text)(Complete pgs 7 and 8 of sheets, use pgs 123-128 of text) Test your knowledge pg 127Test your knowledge pg 127

Importance of BiodiversityImportance of Biodiversity 1.1. Could provide us with future life changing Could provide us with future life changing

medicinesmedicines 2.2. May provide us with a genetic storehouse May provide us with a genetic storehouse

in many wild species which could help in many wild species which could help humans and plants recover from diseasehumans and plants recover from disease

3.3. Could provide us with future varieties of Could provide us with future varieties of food food

4.4. May add to our education of the nature May add to our education of the nature around us. around us. (Sheets page 14, see text pgs 139-140)(Sheets page 14, see text pgs 139-140)

Factors such as pollution and grazing reduce Factors such as pollution and grazing reduce the variety of species in an ecosystemthe variety of species in an ecosystem

They act selectively on populations They act selectively on populations disadvantaging some species and allowing disadvantaging some species and allowing others to thrive by eliminating their others to thrive by eliminating their competition.competition.

Reduction in BiodiversityReduction in Biodiversity Human activity can reduce biodiversity through the Human activity can reduce biodiversity through the

destruction of habitats destruction of habitats (Pages 8-13, see text pgs 129 - 138),(Pages 8-13, see text pgs 129 - 138), ie; ie; Disruption of food webs Disruption of food webs GrazingGrazing Pollution – Acid rainPollution – Acid rain

- Sewage- Sewage - Thermal pollution- Thermal pollution

DeforestationDeforestation DesertificationDesertification Mass extinctionMass extinction Over-huntingOver-hunting Habitat destructionHabitat destruction

Disruption of Food WebsDisruption of Food Webs Food webs are generally more stable than food Food webs are generally more stable than food

chains, and can normally withstand small/ temporary chains, and can normally withstand small/ temporary disruptionsdisruptions

If , however an organism is affected by an external If , however an organism is affected by an external factor, then this will have a knock-on effect in a food factor, then this will have a knock-on effect in a food chainchain

A chain having only a few links will be more A chain having only a few links will be more seriously affected than a longer chainseriously affected than a longer chain

Myxomatosis is an example of an external factor Myxomatosis is an example of an external factor which nearly wiped out the rabbit population in which nearly wiped out the rabbit population in BritainBritain

GrazingGrazing Grazing can be of an advantage to some plant species Grazing can be of an advantage to some plant species

and a disadvantage to othersand a disadvantage to others If natural grasslands go un-grazed, some of the If natural grasslands go un-grazed, some of the

stronger species will thrive on the available resources, stronger species will thrive on the available resources, causing other weaker species to diecausing other weaker species to die

This reduces biodiversityThis reduces biodiversity If on the other hand, animals are left to over-graze, If on the other hand, animals are left to over-graze,

this can also lead to a reduction in biodiversitythis can also lead to a reduction in biodiversity This is because the plants are not able to grow and This is because the plants are not able to grow and

reproduce.reproduce.

PollutionPollutionAcid RainAcid Rain

Caused by the burning of fossil fuels (coal, oil) Caused by the burning of fossil fuels (coal, oil) Release sulphur dioxide (poisonous gas), damages many plant Release sulphur dioxide (poisonous gas), damages many plant

speciesspecies Ie.different Lichen species tolerate different levels of SOIe.different Lichen species tolerate different levels of SO22

pollutionpollution As air pollution increases, the variety of lichen species As air pollution increases, the variety of lichen species

decreasesdecreases Water and land environments can also be affected by pollutionWater and land environments can also be affected by pollution

Ie. a reduction in the number of fish speciesIe. a reduction in the number of fish species

SewageSewage

Untreated sewage may be released into rivers in Untreated sewage may be released into rivers in densely populated areas if the sewage works become densely populated areas if the sewage works become overloadedoverloaded

This provides food for bacteria (which feed on This provides food for bacteria (which feed on organic waste)organic waste)

(Organic waste ie. Dead skin cells, faeces, urine, hair, (Organic waste ie. Dead skin cells, faeces, urine, hair, plant/animal food waste)plant/animal food waste)

As sewage bacteria oxygen fish etc.As sewage bacteria oxygen fish etc. This could result in loss of clean water species This could result in loss of clean water species

ie. Loss of species diversityie. Loss of species diversity

Thermal PollutionThermal Pollution

Some power stations use local river water to cool their Some power stations use local river water to cool their generatorsgenerators

When the water is returned to the river it is considerably When the water is returned to the river it is considerably warmer, and causes thermal pollutionwarmer, and causes thermal pollution

DeforestationDeforestation The complete clearing of vast areas of natural forests The complete clearing of vast areas of natural forests

and the failure to plant new forests in their place;and the failure to plant new forests in their place;

Loss of regular water flow, so loss of sponge Loss of regular water flow, so loss of sponge effect = effect = rivers fail to provide a regular supply rivers fail to provide a regular supply of water for human consumption and irrigationof water for human consumption and irrigation

Loss of rain water from hillsides = Loss of rain water from hillsides = flooding of flooding of low-lying downstream areas, cannot be low-lying downstream areas, cannot be cultivatedcultivated

Erosion of fertile top soil = Erosion of fertile top soil = fertility of hillside fertility of hillside reduced, rivers, lakes, irrigation channels and reduced, rivers, lakes, irrigation channels and dams become blocked, muddy and undrinkabledams become blocked, muddy and undrinkable

Less water evaporation into atmosphere = Less water evaporation into atmosphere = reduction in rainfall, so drier climatereduction in rainfall, so drier climate

More COMore CO22 (burning) not removed by (burning) not removed by photosynthesis and less Ophotosynthesis and less O2 2 = = extra carbon extra carbon dioxide may add to the greenhouse effect.dioxide may add to the greenhouse effect.

DesertificationDesertification Removal of protective shrubs and plants which Removal of protective shrubs and plants which

act as wind breaks which normally hold the act as wind breaks which normally hold the soil togethersoil together

Removal causes the soil to dry out and lose Removal causes the soil to dry out and lose fertility.fertility.

Mass Extinction, Over-hunting and Mass Extinction, Over-hunting and Habitat destructionHabitat destruction

Fossil fuels take millions of years to form, and Fossil fuels take millions of years to form, and are quickly becoming depleted due to over useare quickly becoming depleted due to over use

As they take so long to form it will take as As they take so long to form it will take as long again to form morelong again to form more

Hundreds of birds and animals have become Hundreds of birds and animals have become extinct over the centuries, and many more are extinct over the centuries, and many more are in dangerin danger

Two major contributors are over-hunting and Two major contributors are over-hunting and habitat destructionhabitat destruction

Human activities are causing the current wave Human activities are causing the current wave of extinction to run at about 400 times its of extinction to run at about 400 times its natural rate.natural rate.

(See pgs 8-13)(See pgs 8-13) Test your knowledge pg 141 of text.Test your knowledge pg 141 of text.

Behavioural AdaptationsBehavioural Adaptationsin Animalsin Animals

Animals exhibit behavioural responses to their Animals exhibit behavioural responses to their environmentenvironment

Behavioural responses/adaptations are of survival value to Behavioural responses/adaptations are of survival value to the animalthe animal

The way an animal responds depends on the environmental The way an animal responds depends on the environmental stimulus which it has triggered its internal receptorsstimulus which it has triggered its internal receptors

Theses receptors are linked with the sense organs which in Theses receptors are linked with the sense organs which in turn communicate with the nervous systemturn communicate with the nervous system

The sense organ detects an environmental stimulus then The sense organ detects an environmental stimulus then transmits nerve impulses through the nervous system, transmits nerve impulses through the nervous system, causing an effector to create a behavioural responsecausing an effector to create a behavioural response

The effector could be muscles or glands. The effector could be muscles or glands. (See pgs15-17)(See pgs15-17)

Pg 16/17 Activity 2.1, text pgs 143 - 144Pg 16/17 Activity 2.1, text pgs 143 - 144 Pg 17/18 Activity 2.2, text pgs 145 -147Pg 17/18 Activity 2.2, text pgs 145 -147 Testing your knowledge pg 147 of text.Testing your knowledge pg 147 of text.

Competition Between PlantsCompetition Between Plants If any of the following resources are in short supply If any of the following resources are in short supply

plants will compete with one another for them;plants will compete with one another for them; LightLight WaterWater Soil NutrientsSoil Nutrients

Same species plants will have intense competition for Same species plants will have intense competition for these resources. these resources. (See sheets pgs 19- top 20, text pg 147)(See sheets pgs 19- top 20, text pg 147)

Pg 19 Activity 2.3, text pgs 148 – 149.Pg 19 Activity 2.3, text pgs 148 – 149.

Competition Between AnimalsCompetition Between Animals Animals will compete with one another for Animals will compete with one another for

resources such as;resources such as; FoodFood WaterWater ShelterShelter

(See sheets pg 20, text pgs 150 - 152)(See sheets pg 20, text pgs 150 - 152)

Test your knowledge pg 152 of text.Test your knowledge pg 152 of text.

Applying your knowledge pgs 153 – 158 of Applying your knowledge pgs 153 – 158 of texttext

What you should know pgs 158 – 160 of text.What you should know pgs 158 – 160 of text.