Topic 2 Part 6 Responses to stimuli

Question 1

What is a stimulus?

Answer 1

A stimulus is something that elicits a response

Question 2

Can you distinguish between a heterotroph and an autotroph?

Answer 2

A heterotroph gets its food from other organic sources whereas an autotroph makes its own food.

Question 3

What does Chemotaxis stand for?

Answer 3

(from chemo meaning chemical and taxis meaning movement)

Question 4

What is Chemotaxis?

Answer 4

is the movement of organisms due to chemical stimulation

Question 5

What can chemicals be?

Answer 5

chemoattractants or chemorepellents

Question 6

What is chemoattractants?

Answer 6

the chemoattractants result in the organism moving towards the chemical

Question 7

What is chemorepellents?

Answer 7

the chemorepellants result in the organism moving away.

Question 8

What is a plants response to a stimulus known as?

Answer 8

Tropism

Question 9

What is phototropism?

Answer 9

Plants growing towards sun

Question 10

What is gravitropism?

Answer 10

Plants also grow up, defying gravity, the force that attracts a body towards the centre of the Earth

Question 11

What is an auxin?

Answer 11

any group of plant hormones that regulate growth

Question 12

What are synapses?

Answer 12

Gaps between neurons

Question 13

Are there the same number of entry points for impulses entering the cell body as exit points for the impulses leaving the cell body?

Answer 13

No, there are numerous routes for impulses to enter the cell body, but only one route out for the impulse.

Question 14

What method of signal transmission is used within the neuron and what system is used to transmit messages between neurons?

Answer 14

Impulses are transmitted as electrical messages within a neuron and as chemical messages between neurons.