1.6 - Response and Regulation

Question 1

What does the receptor do?

Answer 1

Receives the stimulus by one of the 5 senses

Question 2

What does the sensory neurone do?

Answer 2

Takes electrical impulse from the receptor to the CNS

Question 3

What does the CNS do?

Answer 3

Brain- involves conscious decisions with the spinal cord

Spinal cord- automatic responses

Question 4

What does the motor neurone do?

Answer 4

Takes the electrical impulse from the CNS to an effector

Question 5

What does the effector do?

Answer 5

Response by the body

Usually muscular but can be glandular

Question 6

What is a tropism?

Answer 6

An involuntary response involving the growth or turning movement of a plant in response to an environmental stimulus

Question 7

What is photo and geotropism?

Answer 7

Photo- response by plant to light

Geo- response by plant to gravity

Question 8

How could we measure positive geotropism?

Answer 8

By measuring the length and angle of roots

Question 9

What happens to the plants when light is coming from all directions?

Answer 9

The plants will bend in all directions from where they received the light

Question 10

How does light affect the growth?

Answer 10

• shoot grows towards the light
• when a shoot receives light from 1 side, the auxin is found on the shaded side so elongates
• the shoots bend towards the light

Question 11

How does gravity affect the growth of a plant?

Answer 11

• the shoot grows up away from gravity
• root grows towards gravity
• in the shoot the auxin stimulates it to grow more on the lower side
• shoot bends upward
• in the root the auxin builds up on the lower side but auxin slows down growth

Question 12

What is homeostasis?

Answer 12

Keeping the internal conditions of the body the same

Question 13

What is negative feedback?

Answer 13

The mechanism by which the body maintains conditions within particular limits

Question 14

What is glycogen?

Answer 14

Insoluble carbohydrate stored in liver

Question 15

What is glucagon?

Answer 15

A hormone released by the pancreas which raises blood sugar

Question 16

What is glucose?

Answer 16

A soluble sugar carried in blood

Question 17

What is insulin?

Answer 17

A hormone that decreases the blood sugar and is released by the pancreas

Question 18

When would the blood sugar rise?

Answer 18

After eating a meal high in carbohydrates

Question 19

What does insulin do?

Answer 19

It changes soluble glucose into insoluble glycogen which is stored in the liver

Question 20

What does glucagon do?

Answer 20

It changes insoluble glycogen into soluble glucose that enters the bloodstream

Question 21

Describe how to test a patient’s urine for sugar

Answer 21

1. Collect the patient’s urine into a test tube
2. Put a few drops of Benedicts Reagent into it
3. Put test tube in a water bath at 80 degrees for 5 minutes
4. If the urine contains sugar it should be brick red

Question 22

Describe what happens in the body when it is too hot

Answer 22

• sweat: heat of skin evaporates the sweat and cools the skin
• vasodilation (blood vessels get wider) more blood flow through capillaries as heat is lost to the atmosphere and it cools the body. Causes redness in skin
• hairs lie flat: less air trapped for insulation

Question 23

Describe what happens in the body when it is too cold

Answer 23

Shivering- contraction and relaxation of muscles produces heat
Sweat gland stops releasing sweat
Hairs are raised: trap a thicker layer of air against the skin surface providing more insulation
-air is a poor conductor allowing less heat to escape
-vasoconstriction (capillaries near surface constrict) so less blood goes to the surface. Causes pale skin when cold

Question 24

What is the role of hair?

Answer 24

They control the body temperature. They lie flat when we are warm, and rise when we are cold

Question 25

What is the role of the erector muscle?

Answer 25

It can contract to raise the hair when cold and relax to lower the hair when hot

Question 26

What is the role of the sweat gland?

Answer 26

It removes water and salt from blood, producing sweat

Question 27

What is the role of the sweat duct?

Answer 27

It carries sweat to the surface of the skin

Question 28

What is the role of the sweat pore?

Answer 28

Sweat is released onto the skin through the pore, as the sweat evaporates it cools the skin and body

Question 29

What is the role of the blood capillaries?

Answer 29

They can change the flow of blood through them to help control heat loss from the skin

Question 30

What is a stimulus?

Answer 30

Something in the environment that causes us to react e.g Bright light