Module 5 - plant responses Flashcards
What is plant responses?
plants respond to changes in their environment in their environment to manage their chances of survival, e.g. towards the light to increase rate of photosynthesis
what is tropism?
the response to a plant to a directional stimulus
what are growth hormones?
- Plants response to stimuli using growth hormones
- as they have a circulatory system or a nervous systems like humans
What are auxins (IAA)?
they cause cell elongation in shoots (not cell division)
what are gibbrellins?
- they responsible for controlling flowering and germination
what are common about all growth hormones?
they are made in the growing regions of the plants - root tips and shoot tips
how do growth hormones move short distances?
- move short diffusion by diffusion and active transport
where do growth hormones move long distances?
in the phloem
what happens in phototropism?
IAA moves to the shaded side of the shoot/root
what happens in geotropism?
IAA always move to the underside
In shoots, what happens in phototropism?
IAA causes cell elongation, shoots grow towards the light
In roots, what happens in phototropism?
IAA inhibits cell growth -> roots grow towards the light
In shoots, what happens in geotropism?
- grow way from gravity, - - - cell elongation
- negative geotropism
In roots, what happens in geotropism?
- grow towards gravity
- Positive geotropism
Plant responses to herbitory - what happens when chemical are released?
- bitter/bad tasting
-toxic
Plant responses to herbitory - example of a chemical
- Tannins -> toxic -> Inhibit enzyme in insects
- Alkeloids e.g. caffeine and cocaine
- attract herbivores - attract wasps to eat caterpillars