Communication and Homeostasis

Question 1

Responding to the environment helps organisms…

Answer 1

Survive.

Question 2

Animals increase their chances of survival by …

Answer 2

Responding to changes in their external environment, e.g by avoiding harmful environments.

Question 3

Animals also respond to their internal environment …

Answer 3

to make sure conditions are always optimal for their metabolism.

Question 4

Plants also increase their chances of survival by…

Answer 4

responding to changes in their environment.

Question 5

Any change in the internal or external environment is called a …

Answer 5

stimulus

Question 6

Receptors detect a stimuli and effectors

Answer 6

produce a response.

Question 7

Receptors detect…

Answer 7

stimuli.

Question 8

Receptors are specific…

Answer 8

they only detect one particular stimulus.

Question 9

There are many different types of receptors that each detect a …

Answer 9

different type of stimulus.

Question 10

some receptors are…

Answer 10

cells

Question 11

Photoreceptors are receptor cells…

Answer 11

that connect to the nervous system.

Question 12

Some receptors are proteins on …

Answer 12

cell surface membranes.

Question 13

Glucose receptors are proteins found in …

Answer 13

the cell membranes of some pancratic cells.

Question 14

Effectors are cells that bring about …

Answer 14

a response to a stimulus, to produce an effect.

Question 15

Give an example of an effector cell.

Answer 15

Effectors include muscle cells and cells found in the glands, e.g the pancreas.

Question 16

To produce a response…

Answer 16

receptors need to communicate with effectors and effectors may need to communicate with other cells.

Question 17

This communication happens via …

Answer 17

cell signalling.

Question 18

Cell signalling can occur between…

Answer 18

adjacent cells or between distance cells.

Question 19

An example of cell signalling in the nervous system…

Answer 19

Cells in the nervous system communicate by secreting chemicals called neurotransmitters., which sends signals to adjacent cells, such as other nerve cells or muscle cells.

Question 20

How does the hormonal system work?

Answer 20

The hormonal system works by releasing chemicals called hormones, which travel in the blood and act as signals to distant cells.

Question 21

Cell surface receptors allow…

Answer 21

cells to recognise the chemicals involved in cell signalling.

Question 22

Changes in the external environment…

Answer 22

can affect your internal environment- the blood and tissue fluid that surrounds your cells.

Question 23

What is Homeostasis?

Answer 23

Homeostasis involves control systems that keep your internal environment roughly constant (within certain limits).

Question 24

Keeping your internal environment constant is…

Answer 24

vital for cells to function normally and to stop them from being damaged.

Question 25

Why is it important to maintain the right core temperature?

Answer 25

This is because temperature affects enzyme activity, and enzymes control the rate of metabolic reaction.

Question 26

What happens to enzymes when body temperature is too high?

Answer 26

If body temperature is too high, enzymes may become denatured. over 40 degrees.

Question 27

Describe how enzymes break down due to denaturing.

Answer 27

The enzymes molecules vibrate too much, which breaks the hydrogen bonds that hold them in their 3D shape.

The shape of the enzyme’s active site is changed and it no longer works as a catalyst. This means metabolic rates are less efficient.

Question 28

What happens when temperatures are too low?

Answer 28

If the body temperature is too low enzyme activity is reduced, slowing the rate of metabolic reactions.

Question 29

What is so important at 37 degrees?

Answer 29

The highest rate of enzyme activity happens at the optimum temperature of 37 degrees.

Question 30

It is also important to maintain the right concentration of glucose in the blood so…

Answer 30

there is always enough for respiration.