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Biology - Unit 5 > Sensory Reception > Flashcards

Flashcards in Sensory Reception Deck (17):
0

What is a stimulus?

A detectable change in the internal or external environment of an organism that produces a response in the organism

1

What is the main advantage of being able to respond to stimuli?

It increases an organisms chances of survival

2

What causes organisms with more appropriate responses to be favoured?

Selection pressure

3

What detects stimuli?

Cells or organs known as receptors

4

What do receptors do?

They transform the energy of a stimulus into some form of energy that can be processed by the organism and leads to a response

5

What carries out the response to a stimuli?

An effector

6

What is one way in which receptors and effectors can communicate?

Via chemicals such as hormones

7

How do the receptors and effectors in animals communicate so rapidly?

The communicate via the nervous system

8

What is each effector and receptor linked to?

A central coordinator

9

What is a taxis?

A simple response whose direction is determined by the direction of the stimulus

10

What sort of organisms respond directly to environmental changes by moving its whole body either towards a favourable stimulus or away from an unfavourable one?

A motile organism

11

Taxes are classified in two ways. What are they?

Positive and negative taxis

12

Name 2 types of taxis

Phototaxis and chemotaxis

13

What is a kinesis?

A form of response in which the random movements of an organism increases in response to unpleasant stimuli

14

What is a kinesis response designed to do?

To bring the organism back into favourable conditions

15

What is a tropism?

A growth movement of part of a plant in response to a directional stimulus

16

Give 3 examples of tropisms

Phototropism, Hydrotropism and Geotropism