Biology - Response And Regulation

Question 1

What is the nervous system made up of?

Answer 1

Brain and spinal chord
Nerves

Question 2

What are the three words to describe reflex actions

Answer 2

Automatic
Rapid
Protective

Question 3

What are sense organs?

Answer 3

Sense organs are a group of receptor cells

Question 4

What do receptors do?

Answer 4

Responds to a specific stimulus

Question 5

What is reflex?

Answer 5

Reaction that happens without a stimulus being sent to the brain

Question 6

Name the 7 main parts of the reflex arc

Answer 6

1) stimulus
2) receptor
3) sensory neurone
4) synapse
5) relay neurone
6) motor neurone
7) effector

Question 7

Name the controlled variables of the Reaction Times experiment

Answer 7

The distance from the thumb and forefinger
The point from which the ruler is dropped

Question 8

Why must conditions inside the body be kept relatively constant?

Answer 8

-body cells work efficiently
- body cells are protected from harmful effects

Question 9

The method bu which conditions are kept constant is ?

Answer 9

Negative Feedback

Question 10

What are Hormones?

Answer 10

Proteins that are chemical messengers carried by the blood

Question 11

What does the hormone insulin do?

Answer 11

Reduces blood sugar levels (when blood sugar levels increase)

Question 12

What does the hormone glycogen do?

Answer 12

Raises blood sugar levels (when glucose is all gone!)

Question 13

What is homeostasis?

Answer 13

Keeping the conditions inside the body relatively constant

Question 14

What are the conditions in which the metabolism can be carried out?

Answer 14

-within a narrow temperature and pH
- with appropriate nutrients
- with the correct concentration of water

Question 15

How is the optimum body temperature maintained?

Answer 15

By the nervous system

Question 16

What happens when we are too hot?

Answer 16

• The hair lies flat, no layer of insulating air
• vasodilation, blood vessel diameter increases, increasing the blood flow to the skin . Meaning more heat energy is lost by radiation
• The sweat gland produces sweat. The sweat travels up the sweat duct and passes out onto the skin’s surface through the sweat pore. This cools you down when the sweat evaporates.

Question 17

What happens when we are too cold?

Answer 17

-The erector muscles contract to make the hairs stand on end. This traps an insulating layer of air.
-Less or no sweat is released from the sweat gland.
-The blood vessels near the skin’s surface constrict. This means less blood is near the skin’s surface and so less heat energy is lost by radiation.