B1 - Nerves & Hormones

Question 1

Why must body temperature be kept within a narrow range?

Answer 1

So that enzymes and body reactions work well.

Question 2

Describe IVF.

Answer 2

Eggs are collected from the ovaries. The eggs are fertilised with sperm; a ball of cells, or embryo forms which is inserted into the woman’s uterus.

Question 3

Suggest why IVF clinics are asked to reduce multiple births.

Answer 3

Babies are born with low birth weight; multiple births increase the risk of harm to mother and baby (i.e. miscarriages or premature birth).

Question 4

How is information passed across a synapse?

Answer 4

By a chemical transmitter

Question 5

Apart from using insulin, how else can diabetes sufferer reduce their blood glucose?

Answer 5

Controlled diet, exercise, pancreas transplant

Question 6

Why does the blood glucose concentration decrease during a race?

Answer 6

Used during respiration to provide energy for the race.

Question 7

What do anabolic steroids do?

Answer 7

They increase the growth of muscle.

Question 8

Why are anabolic steroids banned in sport?

Answer 8

To ensure fairness during competition; anabolic steroids have harmful side effects.

Question 9

Name one plant hormone.

Answer 9

Auxin

Question 10

List the main features of asexual reproduction.

Answer 10

No fertilisation, only one parent, no mixing of genetic material, no genetic variation (only clones).

Question 11

Give one advantages of using tissue cultures rather than cuttings for plant reproduction.

Answer 11

Less damage to parent plant and many more plants can be grown/produced from one parent plant using tissue cultures.

Question 12

Describe the pathway taken by the nerve impulse in the blink reflex.

Answer 12

From light sensitive cells to sensory neurone to the brain/CNS to the motor neurone to the eye lid muscle (effector).

Question 13

Other than plant reproduction, give a use for plant hormones.

Answer 13

Weed killer

Question 14

What is a hormone?

Answer 14

Chemical messenger

Question 15

Which organ produces hormones?

Answer 15

A gland

Question 16

How are hormones transported inside the body?

Answer 16

Blood

Question 17

Describe how the hormones FSH, oestrogen and LH are involved in the control of the menstrual cycle.

Answer 17

FSH stimulates oestrogen production and egg maturation; oestrogen then inhibits further FSH production, stimulates LH production as well as the build-up of the uterus lining; LH stimulates ovulation.

Question 18

Give two differences between a reflex and a hormone controlled action.

Answer 18

A reflex is faster and happens over a shorter period of time; reflex involves impulses but hormones involves chemicals; hormones involves circulatory system, reflex involves nervous system.

Question 19

Which word describes a change in the environment?

Answer 19

Stimulus

Question 20

Give one medical use of thalidomide today.

Answer 20

Sleeping pill; treating leprosy

Question 21

Which two hormones are used in IVF treatment?

Answer 21

FSH and LH

Question 22

Name two hormones involved in the menstrual cycle.

Answer 22

Oestrogen, progesterone, LH, FSH

Question 23

Explain how hormones used in contraceptive pills can prevent conception.

Answer 23

FSH production is inhibited so that the egg does not mature.

Question 24

Name the gland that produces FSH.

Answer 24

Pituitary

Question 25

Name the gland that produces oestrogen.

Answer 25

Ovaries

Question 26

Give two disadvantages of IVF treatment.

Answer 26

Low success rate, expensive, risk of multiple births, stressful (emotional)

Question 27

Describe what happens at a synapse when an impulse arrives.

Answer 27

Chemicals/transmitters diffuse across the gap so that the impulse can pass from one neurone to the next.

Question 28

Why is it dangerous when information from the skin does not arrive at the brain?

Answer 28

The stimulus cannot be felt so there is a risk of serious or permanent harm. (E.g. skin burns)

Question 29

Name three conditions which are controlled inside our body.

Answer 29

Heart rate, blood pressure, blood glucose, water, minerals/salts, temperature

Question 30

Why is it difficult to give up an addictive drug?

Answer 30

An addictive drug alters the body chemistry so the user craves the drug. Withdrawal symptoms start once the user stops taking the drug.

Question 31

Why do some oral contraceptives contain oestrogen?

Answer 31

Because oestrogen inhibits FSH production; without FSH the egg does not mature and ovulation does not happen.

Question 32

Why do you sweat more when you exercise?

Answer 32

Exercise raises the body temperature/makes you feel hot and sweating helps to cool down the body.

Question 33

Why do you need to drink more water when you exercise?

Answer 33

A lot of water is lost during sweating which needs to be replaced to prevent dehydration.

Question 34

What are the disadvantages of using contraceptive hormones?

Answer 34

Prolonged use might lead to infertility; might cause weight gain, mood swings, breast cancer or headaches; increase in STDs as condoms are not used

Question 35

Why does a blockage of an oviduct/fallopian tube cause infertility?

Answer 35

Egg and sperm cannot meet.

Question 36

Describe how changes in the uterus lining adapt it for its function if an egg is fertilised.

Answer 36

The lining builds so that a zygote could implant- the surface area increases so there is a better chance that the zygote attaches; increase in blood vessels to provide nutrients for the zygote; it thickens to form the placenta

Question 37

Which organ controls the amount of water in the body?

Answer 37

Kidney

Question 38

How does your body control the rate at which your kidney re-absorbs water?

Answer 38

With ADH from the pituitary gland