Topic 15 Coordination and Response in Plants

A big tree falls in a forest, but its roots are still in contact with the soil. The branches of this fallen tree grow straight up (vertically). This happens in response to:

• Water and light

• Water and minerals

• Gravity and water

• Light and gravity

Any change in the environment to which an organism responds is called:

• Stimulus

• Coordination

• Response

• Hormone

Auxins are responsible for _____________ of a plant

• Colour change

• Watering

• Growth

• breaking seed dormancy

Where is auxin formed

• Tip of stem and root

• Leaves

• Embryo

• All

In general, plants respond to _________ by changing their rate or direction of growth. They may grow either towards or away from it.

• stimuli

• change

• danger

• environment

Growth towards a stimulus is said to be a __________ response and growth away from a stimulus is a __________ response.

• positive, negative

• negative, positive

• positive, positive

• negative, negative

A _______ is a response growth by a plant, in which the direction of the growth is affected by the direction of the stimulus

• tropism

• tropical

• photosynthesis

• relativeness

Two important stimulus of plants are

• light

• gravity

• water

• fertilizer

________ normally grow towards light

• shoots

• roots

• stem

• leaves

__________ tend to grow away from the pull of gravity while _______ normally grow towards it.

• Shoots, roots

• Roots, shoots

• Shoots, shoots

• Roots, roots