B11 Hormonal coordination – SLOP (separate) mark scheme

Spec points 4.5.3-4

*Questions require further thinking

B11.1 Principles of hormonal control (4.5.3.1)

1. Name the system apart from the nervous system that coordinates the body. (1)

- Endocrine system

2. Define ‘hormones’. (1)

- Chemicals produced in one area of the body that have an effect on the

functioning of another area of the body

3. Where are hormones produced? (1)

- Endocrine glands

4. How are hormones transported from one organ to another? (1)

- through the bloodstream

5. Name the ‘master gland’ and describe how it brings about impact on the body. (3)

- Pituitary gland

- Secretes many different hormones

- Can have direct impact on the body (eg. ADH on kidney)

- Can control other endocrine glands to release more hormones (eg. FSH to

ovaries to make oestrogen)

6. Label the endocrine glands. (6)

7. *Comp

are the

hormonal

sy

st

em

and

Pituitary gland

Thyroid gland

Adrenal gland

Pancreas

Testis

Ovary

nervous system. (4)

- Hormones: slower effects; Nerves: faster effects

- Hormones: long-lasting effects; Nerves: short effects

- Hormones: transported in bloodstream; Nerves: neurones

- Hormones: coordinated by chemicals/proteins; Nerves: coordinated by

electrical impulses

Students should be able to describe the principles of hormonal coordination and

control by the human endocrine system. The endocrine system is composed of

glands which secrete chemicals called hormones directly into the bloodstream. The

blood carries the hormone to a target organ where it produces an effect. Compared

to the nervous system the effects are slower but act for longer. The pituitary gland in

the brain is a ‘master gland’ which secretes several hormones into the blood in

response to body conditions. These hormones in turn act on other glands to

stimulate other hormones to be released to bring about effects.

Students should be able to identify the position of the following on a diagram of the

human body:

• pituitary gland

• pancreas

• thyroid

• adrenal gland

• ovary

• testes.

B11.2 The control of blood glucose levels (4.5.3.2)

1. Name the endocrine gland that controls blood glucose level (BGL). (1)

- Pancreas

2. What is the effect of insulin on BGL? (1)

- It decreases BGL

3. Name the hormone that increases BGL. (1)

- Glucagon

4. Name the organ that secretes the two hormones to regulate BGL. (1)

- Pancreas

5. When would a person’s BGL increase during a day (24hr)? (1)

- After a meal/eating

6. *Sketch a graph to show how a healthy person’s BGL fluctuates over 24 hours,

starting from midnight. Annotate the diagram to indicate reason for any

significant BGL increase or decrease. No exact BGL values are needed. (4)

- Axes labelled (x: time; y: BGL in arbitrary unit)

- An increase in BGL after each meal

- A decrease in between meal times

- Correct relevance of events to fluctuations

7. *Explain the primary reason why a person’s BGL would decrease eventually. (2)

- Cells take in glucose

- For respiration (to release energy)

8. Describe the actions of insulin – how does it lower BGL? (3)

- Increase glucose uptake into cells (by opening glucose channels on cell

membrane) increase respiration

- Convert glucose to glycogen as storage in muscles and liver

- Convert glucose to lipids as storage

9. Describe the actions of glucagon. (2)

- Converts stored glycogen into glucose

- Makes glucose from amino acids and lipids (gluconeogenesis)

10. Explain the importance of maintaining a stable blood glucose level. (3)

- Glucose needed for cellular respiration

- Releasing energy for body’s metabolic reactions

- Too much or too little glucose in blood causes problems with respiration

Blood glucose concentration is monitored and controlled by the pancreas. If the

blood glucose concentration is too high, the pancreas produces the hormone insulin

that causes glucose to move from the blood into the cells. In liver and muscle cells

excess glucose is converted to glycogen for storage. Students should be able to

explain how insulin controls blood glucose (sugar) levels in the body.

(HT only) If the blood glucose concentration is too low, the pancreas produces the

hormone glucagon that causes glycogen to be converted into glucose and released

into the blood.

(HT only) Students should be able to explain how glucagon interacts with insulin in a

negative feedback cycle to control blood glucose (sugar) levels in the body.

B11.3 Treating diabetes (4.5.3.2)

1. What is diabetes?

- A disorder where the blood glucose level is not controlled

2. Describe two differences between types 1 and 2 diabetes. (4)

- Type 1: Pancreas cannot make sufficient insulin

- Types 2: Cells do not respond to insulin

- Type 1: Symptoms start appearing in young children/teenagers

- Type 2: Symptoms start appearing as people age

3. State three symptoms of diabetes. (3)

- Frequent urination

- Feeling thirsty constantly

- Tiredness/Lack of energy

- Weight loss

4. *Explain why diabetic patients may lose weight. (3)

- Cells cannot take up sufficient glucose

- Less glucose available for respiration

- Starts to break down proteins as fuel for respiration

5. Suggest two risk factors for developing diabetes. (2)

- Obesity

- Genetic factors

6. *State two ways to diagnose someone as diabetic. (2)

- Urine test

- Blood test

7. Compare the treatments of types 1 and 2 diabetes. (2)

- Type 1: Insulin injection

- Type 2: Strict carbohydrate intake; Regular exercise; Medicine

8. One type of diabetes can be cured. State which one it is and explain how. (3)

- Type 1 diabetes

- Pancreas transplant

- Healthy pancreas can make sufficient insulin

9. *Following Q16, suggest a problem with the treatment. What is a possible

solution to this problem? (2)

- Organ rejection by the patient’s own immune system

- Immunosuppressant drugs

10. *Explain why insulin must be injected rather than taken by mouth. (2)

- Insulin is a protein

- Can be digested by protease in the stomach

11. *Explain why insulin injection is not an appropriate treatment for type 2 diabetes.

(2)

- Cells no longer respond to insulin for type 2 diabetes

- Further insulin injection brings about no effect

Type 1 diabetes is a disorder in which the pancreas fails to produce sufficient insulin.

It is characterised by uncontrolled high blood glucose levels and is normally treated

with insulin injections. In Type 2 diabetes the body cells no longer respond to insulin

produced by the pancreas. A carbohydrate controlled diet and an exercise regime are

common treatments. Obesity is a risk factor for Type 2 diabetes.

Students should be able to compare Type 1 and Type 2 diabetes and explain how

they can be treated.

Students should be able to extract information and interpret data from graphs that

show the effect of insulin in blood glucose levels in both people with diabetes and

people without diabetes.

B11.4 The role of negative feedback (4.5.3.7)

1. Describe how negative feedback works. (2)

- Body detects a change in internal environment

- Responds to reverse the effect of that change

2. Suggest two hormonal controls that involve negative feedback. (2)

- BGL control

- Temperature regulation

- Water balance control

- thyroxine levels

3. What does thyroxine control? (1)

- Metabolic rate

4. Which organ secretes thyroxine? (1)

- Thyroid gland

5. *Some people do not produce enough thyroxine. Suggest two possible reasons.

(2)

- Insufficient iodine in their diet

- Thyroid gland not functioning properly

- Pituitary gland not functioning properly

- Insufficient TSH secreted

6. Describe how the level of thyroxine is regulated in the body. (6)

- Brain detects fall in thyroxine levels

- Pituitary gland releases more TSH (thyroid stimulating hormone)

- TSH travels to thyroid gland stimulate it to produce more thyroxine

- Brain detects increase in thyroxine levels

- Signals pituitary gland to release less TSH

- Negative feedback system

Accept opposite description (eg. Brain detects increase…)

7. Under what situation would adrenaline be released? (1)

- Stressed, angry, frightened

- In response to danger (prepare for fight-or-flight)

8. *Describe three differences between thyroid glands and adrenal glands. (3)

- Thyroid: produces thyroxine; Adrenal: produces adrenaline

- Thyroid: constant production; Adrenal: produces only when required

- Thyroid: involves negative feedback; Adrenal: does not involve NF

- Thyroid: located in neck; Adrenal: located above kidneys

9. Describe three effects of adrenaline. (3)

- Increase heart rate

- Increase breathing rate

- Convert stored glycogen to glucose for more respiration

- Pupils dilate

- Increase mental awareness

- More blood flow to muscles (away from digestive system)

10. Explain why blood is directed to the brain and muscles and away from the

digestive system when there is more adrenaline. (3)

- Boosts delivery of oxygen and glucose to brain and muscles

- More respiration

- More energy to fight or escape in response to danger

Students should be able to explain the roles of thyroxine and adrenaline in the body.

Adrenaline is produced by the adrenal glands in times of fear or stress. It increases

the heart rate and boosts the delivery of oxygen and glucose to the brain and

muscles, preparing the body for ‘flight or fight’. Thyroxine from the thyroid gland

stimulates the basal metabolic rate. It plays an important role in growth and

development. Thyroxine levels are controlled by negative feedback.

B11.5 Human reproduction + B11.6 Hormones and the menstrual cycle (4.5.3.4)

1. Describe three secondary sexual characteristics that only males develop during

puberty. (3)

- Broader chest and shoulders

- Facial hair growth

- Larynx grows bigger

- Deeper voice

- Testes grow and start producing sperm

2. Name the hormone that triggers secondary sexual characteristics in males. (1)

- Testosterone

3. Following Q2, where is this hormone produced? (1)

- Testes

4. Describe three secondary sexual characteristics that females develop during

puberty. (3)

- Breasts develop

- Wider hips

- Menstruation starts – eggs mature every month

- Uterus grows

5. Name the hormone that triggers secondary sexual characteristics in females. (1)

- Oestrogen

6. Name three secondary sexual characteristics that both genders develop. (3)

- Growth spurt

- Pubic hair growth

- External genitals grow and skin darkens

7. Name the four hormones involved in the menstrual cycle and state where they

are made. (8)

- FSH (Follicle stimulating hormone) – pituitary gland

- LH (Luteinising hormone) – pituitary gland

- Oestrogen – ovaries

- Progesterone – ovaries

8. Following Q7, state the functions of these four hormones. (4)

- FSH stimulates egg maturation

- Oestrogen stimulates development of uterus lining

- LH triggers ovulation

- Progesterone maintains uterus lining

9. How long does one menstrual cycle last? (1)

- 28 days

10. Describe what menstruation is. (1)

- The shedding of uterus lining along with the unfertilised egg

11. Describe what ovulation is. (1)

- The process where a matured egg is released from the ovary

12. Name the cells that surround immature eggs in the ovaries. (1)

- Follicle

13. Compare sperm and egg production in males and females. (2)

- Sperms are continuously produced in males’ testes as puberty starts

- Females are born with a set number of immature eggs

14. Illustrate the events that happen during a menstrual cycle. (6)

- Day 1: Menstruation starts – shedding of uterus lining and unfertilized egg

- New egg starts to mature

- Uterus lining redevelops

- Day 14: Ovulation occurs

- New mature egg travels via oviduct/fallopian tube to the uterus

- No fertilisation: Egg embeds itself into uterus lining menstruation starts

15. Following Q13, explain how the four female hormones are involved in the process.

Include the organs that secrete them, their actions and interactions with one

another. (10)

- Pituitary gland releases FSH

- FSH travels to ovaries to stimulate egg maturation

- Ovaries produces oestrogen (via FSH stimulation)

- Oestrogen stimulates development of uterus lining

- Oestrogen travels to pituitary gland to inhibit further FSH releases

- Oestrogen stimulate LH release by pituitary gland

- LH travels to ovaries to trigger ovulation

- Progesterone is released from follicle in ovaries as ovulation occurs

- Progesterone maintains uterus lining

- Progesterone inhibits both FSH and LH

16. At which stage is a woman more likely to get pregnant? (1)

- Days 14-28

17. Why is progesterone level kept high after ovulation occurs? (1)

- To enable successful implantation should fertilisation occurs

18. *Sketch a graph to illustrate the changes in the levels of these four hormones

over one menstrual cycle, with the start of menstruation as day 1. (4)

Students should be able to describe the roles of hormones in human reproduction,

including the menstrual cycle. During puberty reproductive hormones cause

secondary sex characteristics to develop. Oestrogen is the main female reproductive

hormone produced in the ovary. At puberty eggs begin to mature and one is released

approximately every 28 days. This is called ovulation. Testosterone is the main male

reproductive hormone produced by the testes and it stimulates sperm production.

Several hormones are involved in the menstrual cycle of a woman.

• Follicle stimulating hormone (FSH) causes maturation of an egg in the ovary.

• Luteinising hormone (LH) stimulates the release of the egg.

• Oestrogen and progesterone are involved in maintaining the uterus lining.

(HT only) Students should be able to explain the interactions of FSH, oestrogen, LH

and progesterone, in the control of the menstrual cycle.

(HT only) Students should be able to extract and interpret data from graphs showing

hormone levels during the menstrual cycle.

B11.7 The artificial control of fertility (4.5.3.5)

1. State the two hormones found in contraceptive pills. (2)

- Progesterone

- Oestrogen

2. Following Q1, explain how they affect the body’s hormonal coordination to

prevent pregnancy. (4)

- Oestrogen inhibits FSH release

- Progesterone inhibits FSH and LH release

- No egg maturation

- No ovulation

3. What are the two barrier methods of contraception? (2)

- Condom

- Diaphragm/cap

4. Explain how intrauterine devices work to prevent pregnancy. (4)

- Contain copper

prevent early embryo implantation

- Slow release of progesterone

prevent build-up of uterus lining + thicken cervix mucus to prevent sperm

entry

5. How does surgical methods prevent pregnancy? (2)

- Sperm ducts and oviducts are tied/cut

- Sperm and egg cells cannot reach the semen/uterus

6. Give one advantage and one disadvantage for each of the following methods.

a.) Contraceptive pills:

- Adv: Very effective

- Disadv: Side effects eg. mood swings, raised blood pressure, risk of breast

cancer

b.) Spermicides:

- Adv: Readily available

- Disadv: Not very effective

c.) Barrier:

- Adv: No side effects

- Disadv: Can be damaged or used incorrectly, leading to pregnancy

d.) Intrauterine devices:

- Adv: Very effective, last for 3-5 years

- Disadv: May cause period problems or infections

e.) Abstinence:

- Adv: If followed properly, zero chance of pregnancy

- Disadv: very unreliable

f.) Surgery:

- Adv: Very effective and permanent

- Disadv: Permanent and irreversible; need general anaesthetic (for females)

Students should be able to evaluate the different hormonal and non-hormonal

methods of contraception. Fertility can be controlled by a variety of hormonal and

non-hormonal methods of contraception. These include:

• oral contraceptives that contain hormones to inhibit FSH production so that no

eggs mature

• injection, implant or skin patch of slow release progesterone to inhibit the

maturation and release of eggs for a number of months or years

• barrier methods such as condoms and diaphragms which prevent the sperm

reaching an egg

• intrauterine devices which prevent the implantation of an embryo or release a

hormone

• spermicidal agents which kill or disable sperm

• abstaining from intercourse when an egg may be in the oviduct

• surgical methods of male and female sterilisation.

B11.8 Infertility treatments (4.5.3.6)

1. Suggest a reason for women’s difficulty in becoming pregnant. Explain. (2)

- Insufficient FSH

no egg maturation

- Insufficient LH

no ovulation

2. Name the two hormones that are used in infertility treatments. (2)

- FSH

- LH

3. When would in vitro fertilisation (IVF) be used as a treatment rather than just

fertility drugs? (1)

- Damaged/blocked oviduct

4. Describe the process of IVF. (6)

- Give mother FSH to stimulate egg maturation

- Give mother LH to induce ovulation

- Collect matured eggs from mother’s ovary

- Fertilise eggs with sperm from father in a Petri dish in the lab

- Allow them to develop into tiny embryos

- Insert 1-2 early embryos back into mother’s uterus

5. What are the disadvantages of IVF? (3)

- Increases chance of multiple pregnancies risky for mothers and babies

- Emotionally and physically stressful

- Low success rate

- Health risks due to fertility drugs

- Expensive

Students should be able to explain the use of hormones in modern reproductive

technologies to treat infertility. This includes giving FSH and LH in a ‘fertility drug’ to

a woman. She may then become pregnant in the normal way.

In Vitro Fertilisation (IVF) treatment:

• IVF involves giving a mother FSH and LH to stimulate the maturation of several

eggs.

• The eggs are collected from the mother and fertilised by sperm from the father in

the laboratory.

• The fertilised eggs develop into embryos.

• At the stage when they are tiny balls of cells, one or two embryos are inserted into

the mother’s uterus (womb).

Although fertility treatment gives a woman the chance to have a baby of her own:

• it is very emotionally and physically stressful

• the success rates are not high

• it can lead to multiple births which are a risk to both the babies and the mother.

(Bio only) B11.9 Plant hormones and responses + B11.10 Using plant hormones

(4.5.4.1-2)

1. Describe what phototropism is. (2)

- The response of a plant to light

- Shoots bend towards light source

2. What is the name of the response of a plant to gravity? (1)

- Gravitropism/Geotropism

3. What causes tropism in plants? (2)

- Uneven distribution of plant hormone

- Auxin

4. Explain the effect of phototropism in young shoots. (4)

- Auxin moves to the side without light

- Auxin encourages shoot growth

- Encourages faster growth on unlit side

- Shoot bends towards light

5. Explain the effect of gravitropism in roots. (4)

- Auxin moves to lower side of roots

- Auxin inhibits root growth

- Therefore the upper side with little auxin grows faster

- Root bends and grows towards the source of gravity

6. *Compare the effects of auxins on shoot and root growth. (2)

- Encourages shoot growth

- Inhibits root elongation (but promote root initiation)

7. Briefly describe an experimental set up to investigate the effect of light on plant

growth. (4)

- Put young germinating seedlings on damp cotton wool in two Petri dishes

- Place one dish in a box with only a slit on one side to allow one-sided light

- Place the other dish in an area with all-rounded light

- Observe and compare their growth after a week

8. Plant hormones can be used in horticulture and agriculture. What is the

difference between those two uses? (2)

- Horticulture = plant growth in gardens for aesthetics

- Agriculture = plant growth on farms for food

9. Explain how auxin works effectively as a weed killer. (3)

- Most weed are broad-leaved plants; most crops of narrow-leaved

- Weed can therefore absorb more auxins

- Lead to uncontrolled growth and die

10. Apart from weed killers, list the other uses of auxins. (2)

- Rooting powder (promotes root initiation, but high dosages inhibit root

elongation)

- Plant tissue culture in cloning (stimulate growth and cell division)

11. Explain why gibberellins are used in agriculture. (3)

- Initiate seed germination/End seed dormancy

- Promote flowering throughout the year

- Increase fruit size

12. Ethene controls fruit ripening. Explain why this needs to be controlled. (3)

- Most fruits are harvested when unripe

- Transported chilled

- Only add ethene to ripen it just before sale to preserve freshness

Plants produce hormones to coordinate and control growth and responses to light

(phototropism) and gravity (gravitropism or geotropism). Unequal distributions of

auxin cause unequal growth rates in plant roots and shoots.

(HT only) Gibberellins are important in initiating seed germination.

(HT only) Ethene controls cell division and ripening of fruits.

(HT only) The mechanisms of how gibberellins and ethene work are not required.

Students should be able to describe the effects of some plant hormones and the

different ways people use them to control plant growth. Plant growth hormones are

used in agriculture and horticulture.

Auxins are used:

• as weed killers

• as rooting powders

• for promoting growth in tissue culture.

Ethene is used in the food industry to control ripening of fruit during storage and

transport.

Gibberellins can be used to:

• end seed dormancy

•promote flowering

• increase fruit size.

Summary of hormones and endocrine glands

Complete the table by filling in the blank spaces.

Endocrine

gland Hormone produced Role of hormone

Pituitary

Growth hormone Controls growth in children

TSH Stimulates thyroid gland to make thyroxine

ADH Affects amount of urine produced by kidneys

FSH Stimulates ovaries to make oestrogen and eggs

LH Stimulates testes to make testosterone and sperm

Thyroid Thyroxine Controls metabolic rate

Pancreas Insulin Decreases blood glucose level

Glucagon Increases blood glucose level

Adrenal Adrenaline Prepares body for stressful situations – ‘fight or flight’ response

Ovaries

Oestrogen

- Trigger development of female secondary sexual characteristics

- Stimulates development of uterus lining

- Stimulates release of LH

- Inhibits release of FSH

Progesterone - Maintains uterus lining

- Inhibits release of FSH and LH

LH Triggers ovulation

Testes Testosterone Trigger development of male secondary sexual characteristics