Responses to Stimuli: Survival & Response Flashcards Preview

A2 Biology: Response to Stimuli > Responses to Stimuli: Survival & Response > Flashcards

Flashcards in Responses to Stimuli: Survival & Response Deck (11):
1

what is a stimulus?

a stimulus is a detectable change in the internal or external environment of an organism that leads to a response in the organism

2

what are stimuli detected by?

receptors (specific to one type of stimulus)

3

what is a co-ordinator?

formulates a suitable response to a stimulus

4

what produces a response?

an effector

5

what are the chemicals used for communications/responses in large, multicellular organisms?

hormones

6

as well as hormonal communications, what more rapid means of communication do animals have?

the nervous system

7

in an animals nervous system, what is each different receptor and effector linked to?

a central co-ordinator

8

summarise the sequence of events involving either chemical control or nerve cells

Stimulus → Receptor → Co-ordinator → Effector → Response

9

what increases the chances of survival for an organism?

the ability to respond to a stimuli

10

what do the organisms that survive have a greater chance of doing?

raising offspring and passing on their alleles to the next generation

11

what is always favouring organisms with more appropriate responses?

a selection pressure