Biology Paper 2 homeostasis and response

Question 1

Define the term homeostasis

Answer 1

This is the regulation of the internal conditions of the cell or organism to maintain optimum conditions for function and response

Question 2

What does CNS mean and what does it consist of?

Answer 2

CNS means central nervous system and consists of the brain and the spinal chord

Question 3

What is the definition of a neurone?

Answer 3

a neurone carries an electrical impulse from one end to another

Question 4

What is meant by a reflex arc?

Answer 4

This is a nervous response that is that is fast and automatic and does not involve the conscious brain

Question 5

What is a synapse?

Answer 5

a synapse is a gap between 2 neurones across within a chemical must diffuse to trigger an electrical impulse to the second neurone

Question 6

What is meant by a chemical response?

Answer 6

This response use hormones which travel into the bloodstream to a target organ to make slow, longer lasting changes

Question 7

What is the endocrice system and what does it consist of?

Answer 7

It consists of glands which secrete hormonesin the bloodstream.

Question 8

What is insulin?

Answer 8

Insulin is produced in the pancreas and is used to decrease glucose levels in the blood

Question 9

What is glycogen?

Answer 9

Glycogen is the long term store of sugar in the body, it is made and stored in the liver and muscles.

Question 10

Define the term accomodation?

Answer 10

This is the process of changing the lens shape to focus on near or distant objects.

Question 11

Define auxin

Answer 11

Auxin is the hormone that controls the plant response to light and gravity.

Question 12

what is a nervous response?

Answer 12

it uses electrical impulses in nerves to make fast short lived changes.

Question 13

what is a stimulus?

Answer 13

a stimulus is a change in the environment.

Question 14

what is a receptor?

Answer 14

A receptor is a type of cell that detects stimuli

Question 15

What is a sensory neurone and what does it do?

Answer 15

A sensory neurone is a neurone that carries electrical impulses from the CNS to the effectors.

Question 16

What is a motor neurone?

Answer 16

a motor neurone is a neurone that carries electrical impulses from the CNS to the effectors.

Question 17

What is an effector?

Answer 17

These are muscles or glands which bring about responses to restore optimum levels

Question 18

What does the thyroid do?

Answer 18

It releases thyroxine which plays an important role in growth and development.

Question 19

What does FSH do and where is it released from?

Answer 19

It is released from the pituatary gland, it causes an egg to be matured in the ovary, it also tells the ovaries to release oestrogen.

Question 20

What does oestrogen do?

Answer 20

Oestrogen stops the production of FSH so that only 1 egg matures in a cycle and it helps repair and thicken the uterus lining and it stimulates the pituatary gland to release LH.

Question 21

What does LH do?

Answer 21

It triggers the release of a mature egg.(ovulation)

Question 22

What does progesterone do?

Answer 22

It maintains the uterus lining during the middle of the menstual cycle and during pregnancy.

Question 23

Define myopia?

Answer 23

Myopia is a condition(short sightedness) where light rays are focussed in front of the retina so objects are not seen clearly.

Question 24

Define hyperopia?

Answer 24

Hyperopia is acondition(long sightedness) this is where the light rays are focussed behind the retina so objects are not seen clearly.

Question 25

What is meant by the process deamination?

Answer 25

Deamination is the process by which amino acids are broken down into ammonia which is then converted into urea which is excreted from the body.

Question 26

What is the retina?

Answer 26

The retina contains receptors which are sensitive to light intensity and colour.

Question 27

What do the cilary muscles do?

Answer 27

They contract and relax to see far and close objects.

Question 28

What is the iris and what does it control?

Answer 28

The iris is a muscle in the eye that controls the amount of light that reaches the retina by controlling the size of the pupil.

Question 29

What is the cornea and what does it do?

Answer 29

The cornea is the transparent area found at the front of the eye it refracts light as it enters and focusses it on the retina.

Question 30

What is the sclera?

Answer 30

The sclera is the white outer layer of the eye strong and tough.

Question 31

What does the cerebral cortex control?

Answer 31

It controls high level functions such as memory language and intelligence.

Question 32

What does the cerebellum control?

Answer 32

It controls the balance and coordination of muscles in the body.