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Flashcards in Homeostasis Deck (23):
0

What is homeostasis?

The process in which organisms maintain a relatively constant or stable environment for body cells (within narrow limits).

1

Define enzymes:

(Proteins) work under certain (optimum) conditions, and cells only work with it.

2

Define stimulus :

Some change in the internal or external environment.

3

Negative feedback?

Response is opposite (counteracts) to the stimulus

4

Positive feedback?

The same direction or encouraged (amplifies) the stimulus.

5

Three homeostasis examples :

1. Body temperature
2. Level of CO2
3. Blood pressure

6

The reflex arc ?

Bypasses the brain and is controlled by the CNS. (Where you give no thought for the reaction) eg. Go outside into the cold is a reflex arc, where answering a question isn't.

7

Do cells respond to a particular hormone?

No, if they respond, it to a particular receptor and not hormone.

8

The effector is?

What has changed to either enhance or counteract the stimulus.
The effector causes the response
Eg. Sweat glands - effector. Sweat - response

9

What detects the stimulus?

The receptor

10

In homeostasis what best describes glands in muscles

Effectors

11

What is the function of the myelin sheath?

Insulation to allow a faster signal throughout the axon

12

Define hormone

A chemical signalling molecule

13

Name two effectors

Sweat glands
Blood vessels

14

What is a statement that is true for ALL viruses ?

Viruses can only reproduce ina living cell.

15

Example of fungi

Mould and yeast

16

Neurotransmitter

Chemicals that cross the synapse to cast messages.

17

Nerve is

Chemically and electrically excitable cell.

18

Axon

Transmits the electrical impulse

19

Synapse

The gaps between neutrons

20

Independent variable

What is changed

21

Dependent variable

What is measured

22

Experimental variable

The uncontaminated agar plate/ the baseline.