Taxes, Kinesis and Tropisms

Question 1

Taxis

Answer 1

Is when an insect moves towards a favorable condition, e.g. worms move towards a dark condition- there is less predators, more food sources, this is a positive taxis

Question 2

Kinesis

Answer 2

Changes direction and rate. When surrounded by an unfavorable condition, direction slows down/decreases

Question 3

What is a Stimulus?

Answer 3

A change in the environment which then triggers a response

Question 4

What is a Tropism?

Answer 4

Tropism is a term where plants respond to a stimulus, (water, gravity, light), controlled by auxin (a group of chemicals) one being IAA.

Question 5

Phototropism (light)

Answer 5

Shoot- plants need light for the LDR, IAA produced in the tip will diffuse from the shoot tips to the shaded part of the shoot, the concentration of IAA will increase in the shaded area, causing the tip to elongate , and bend towards the light
Root- Roots do not need sun light, needs to anchor plant, the IAA will inhibit cell elongation, causing the plant to grow upwards, causing roots to be deeper in soil

Question 6

Gravatropism (gravity)

Answer 6

Shoot- IAA diffuses from upper to lower, elongation occurs so plants grow upwards, (negative tropism)
Root- IAA diffuses from lower to upper, means that plant is anchored down