Coordination And Control

Question 1

What are receptors?

Answer 1

They are cells that detect stimuli (changes in the environment)

Question 2

What do impulses do?

Answer 2

Impulses from receptors pass along sensory neurones to the brain or spinal cord (CNS). Impulses are sent along the motor neurons from the brain (CNS) to the effector organs.

Question 3

What is a neuron?

Answer 3

A cell that is specialised in the transmission of electrical impulses forming the messages of the nervous system.

Question 4

What is a nerve?

Answer 4

A bundle of neurones. It can contain only sensory neurons, only motor neurons or a mixture of both.

Question 5

What is the central nervous system (CNS)?

Answer 5

It consists of two parts, the brain and the spinal cord. It is responsible of the coordination of all the nervous responses as we receive several stimuli at the same time.

Question 6

Summary of a reflex arc:

Answer 6

Stimulus → receptor → sensory neurone → relay neurone → motor neurone → effector → response
Eg:
Pin → skin → sensory neurone → relay neurone → motor neurone → muscles in foot → foot lifts

Question 7

Why are swallowing and breathing reflex actions?

Answer 7

Because these actions need to be preformed whilst unconscious or else you could die

Question 8

Why is adrenaline released in a stressful situation?

Answer 8

Because adrenaline increase alertness

Question 9

Why is it important for organisms to be able to control their internal environment (homostasis)?

Answer 9

So that they can maintain a consistent internal environment. If conditions kept changing, the cells in your body wouldn’t be able to function properly.

Question 10

What are hormones?

Answer 10

They are chemicals that are secreted by various glands in the body but they act on other parts of the body.

Question 11

Where do hormones travel?

Answer 11

In the bloodstream to target their organs and cells

Question 12

Are hormones effects faster or slower than the of the nervous stimulation effects?

Answer 12

Their effects are slower than the effects of the nervous stimulation but they last longer.

Question 13

What is the ideal human body temperature?

Answer 13

37 degrees Celsius

Question 14

What do the ovaries do?

Answer 14

Produce eggs

Question 15

What is the oviduct?

Answer 15

It is the normal site for fertilisation

Question 16

What is the uterus?

Answer 16

It is where the embryo develops.

Question 17

What does the nervous system do?

Answer 17

It creates electrical impulses to enable you to react quickly to your surroundings and coordinate what you do.

Question 18

What is FSH?

Answer 18

It is secreted by the pituitary gland. It makes eggs mature in the ovaries and stimulates the ovaries to produce oestrogen.

Question 19

What is oestrogen?

Answer 19

It is made and secreted by the ovaries. It stimulates the lining of the womb to build up ready for pregnancy. It slows down the production of FSH.

Question 20

What is LH?

Answer 20

When LH levels reach a peak in the middle of the cycle they stimulate the release of a mature egg.

Question 21

What is progesterone?

Answer 21

To keep the lining consistent in the uterus.

Question 22

What is a contraceptive?

Answer 22

A contraceptive contains oestrogen which stops the production of FSH. This means no egg matures. A contraceptive is a substance that will prevent the contraception of an embryo. It will prevent the meeting of an egg and sperm, not to be mistaken for an abortion which will destroy the embryo after the meeting of the egg and sperm.

Question 23

What is a fertility drug?

Answer 23

They stimulate eggs to mature in the ovaries. These can be used in IVF treatments.

Question 24

What does IVF stand for?

Answer 24

In Vitro Fertilisation

Question 25

Which way do shoots grow?

Answer 25

Towards the light and against the force of gravity.

Question 26

Which way to roots grow?

Answer 26

Towards moisture and in the direction of the force of gravity.

Question 27

What is auxin?

Answer 27

Auxin promotes growth in shoots (the more auxin the more growth) and in the roots it inhabits growth (the more auxin the less the root grows)

Question 28

What are hormones called in plants?

Answer 28

Plant growth substances

Question 29

What is a stimuli?

Answer 29

Light, gravity or water/ moisture in the soil.

Question 30

How do plants react?

Answer 30

A plant can make growth responses to certain stimuli, plants do not have a nervous system but they can still detect these stimuli. Plants can respond by either going towards or away from the stimulus. These are growth movements and they occur very slowly.

Question 31

What is positive phototropism?

Answer 31

When a shot to grows towards the light to get the maximum light possible for photosynthesis.

Question 32

What is negative phototropism?

Answer 32

When roots grow away from the light they are said to exhibit negative phototropism.

Question 33

What is positive gravitropism?

Answer 33

When roots grow towards gravity

Question 34

What is negative gravitropism?

Answer 34

When shoots grow upwards as they are not following gravity.

Question 35

What can plant growth hormones be used for?

Answer 35

They can be used in agriculture as weed killers and rooting hormones (in cuttings). If a weed is given auxin it grows quickly, so quickly that the weed cannot keep up and dies.