Year 11

Question 1

What is homeostasis?

Answer 1

How the body maintains a constant internal environment, like needing to control levels of water, iron and oxygen.

Question 2

How does the body keep levels constant?

Answer 2

1) the body has receptors that detect changes
2) sends message to the coordination centre (brain/spinal cord/organ
3) effector (muscle/gland)
4) response

Question 3

What is a stimulus?

Answer 3

A stimulus is a change in the body’s environment for example a bell ringing, a red light

Question 4

What are the two parts of the nervous system?

Answer 4

1) the central nervous system (brain and spinal cord)

2) the peripheral nervous system (all branched nerves)

Question 5

What are the three types of neurone?

Answer 5

1) sensory neurone
2) relay neurone
3) motor neurone

Question 6

What us an electrical impulse?

Answer 6

A message passed along nerve cells called neurones.

Question 7

What are reflex actions?

Answer 7

Fast, automatic and protective responses in the body

Question 8

What are examples of reflex actions?

Answer 8

1) when you touch a very hot object your arm/leg will pull away
2) iris reflex in the eye

Question 9

What is the gap between two neurones called?

Answer 9

A synapse

Question 10

What is the endocrine system?

Answer 10

It is a second coordination control system of the body

Question 11

How does the body react to high blood glucose levels?

Answer 11

1) pancreas detects an increase of blood glucose levels so releases insulin
2) insulin travels in the bloodstream to the liver
3) cells take in more glucose for respiration, the liver takes up excess glucose and stores it as glycogen
4) blood glucose levels are lowered and return to normal homeostatic levels

Question 12

How does the body react to low levels of blood glucose?

Answer 12

1) pancreas detects a decrease of blood glucose levels so releases glucagon
2) glucagon travels through the bloodstream to the river
3) the glucose is released to the blood for the whole body
4) the glucose levels then rise and return to normal homeostatic levels

Question 13

What is the role of the follicle stimulating hormone?

Answer 13

1) it causes an egg to mature in an ovary

2) it stimulates the ovaries to release the hormone oestrogen

Question 14

What is the role of oestrogen in the body?

Answer 14

1) Stimulates the lining of the uterus to grow again after menstruation in preparation for pregnancy
2) Stimulates the pituitary gland to release LH
3) Inhibits the release of FSH so that only one egg matures in the cycle

Question 15

What is the role of the luteinising hormone in the body?

Answer 15

1) Stimulates the release of a mature egg from the ovary
2) Stimulates the ovaries to release progesterone
3) Inhibits the release of oestrogen

Question 16

What is the role of progesterone in the body?

Answer 16

1) Maintains the lining if the uterus during second half of the menstrual cycle and during pregnancy
2) Inhibits both FSH and LH

Question 17

What are the stages of IVF treatment?

Answer 17

1) Giving the mother fertility drugs (FSH and LH) to stimulate the maturation of several eggs
2) The eggs are collected from the mother and fertilised by sperm from the father in the laboratory
3) The fertilised eggs develop into embryos
4) At the stage when they are tiny balls of cells, one or two embryos are inserted into the mothers uterus (womb)

Question 18

What are the disadvantages of IVF treatment?

Answer 18

• Low success rate or not always successful
• High number of multiple births (can lead to low birth rate or harm to mother)
• Expensive
• Stressful/emotional
• Side effects

Question 19

What are the economical issues surrounding embryo screening?

Answer 19

• It is very expensive (for the couple)

* Costs the government (and the tax payers) a lot of money

Question 20

What are the social issues surrounding embryo screening?

Answer 20

• It implies people with genetic problems are “undesirable” which could increase prejudice
• Everyone will want to screen their embryos so they can pick the desirable one

Question 21

What are ethical issues surrounding embryo screening?

Answer 21

• The rejected embryos are destroyed- they could have developed into humans n