Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
21 Cards in this Set
- Front
- Back
|
What are the physical defences of a plant in response to herbivory? |
They can have thorns, inedible tissue, hairy leaves or stings |
|
|
What are the four chemical defences a plant has to herbivory? |
Tannins Alkaloids Terpenoids Pheromones |
|
|
What are tannins? |
Bitter chemicals which can kill insects (Tammy is a bitter person) |
|
|
What are alkaloids and what are the examples? |
Bitter tasting nitrogenous compounds which can interfere with an organs metabolism and kill it
Nicotine and caffeine (Alkalis are bitter and NaOH has an N in it) |
|
|
What are terpenoids? |
Toxins that can kill insects or fungi |
|
|
What are pheromones? |
Chemicals used to communicate between plants if it is being attacked by insects which can cause defensive chemicals to be produced (Heroes evac people in attacks) |
|
|
What are VOCs? |
Volatile organic compounds act as pheromones that attract other organisms such as predators of a particular pest |
|
|
What is thigmotropism in response to? |
Touch |
|
|
What is a coleoptile? |
A protective sheath covering the tip of a young shoot |
|
|
Why are monocots easier to observe and manipulate? |
They consist of a single spike with no apparent leaves when they germinate |
|
|
What happens when the tip of a shoot is removed? |
There is no response to a light stimulus |
|
|
What happens when impermeable Mica is added to the light side of a shoot? |
Auxin can move down the shaded side and elongate the cells so they shoot bends towards the light |
|
|
What happens when the tip of a shoot is removed and gelatin is inserted and tip is replaced? |
Auxins can diffuse through gelatin so the shoot bends towards the light |
|
|
How does a shoot bend towards a light source? |
Auxin is produced at the top of the shoot and accumulates on the shaded side causing cell walls to loosen and causes cell elongation |
|
|
What evidence is there to support that auxin is transported across the shoot? |
If the shoot is cut vertically in half the shoot doesn't bend towards the lights source |
|
|
What is etiolation? |
When a plant grows quickly in the dark to find a light source and then when it is exposed to light, levels of gibberellin falls so leaves can be grown |
|
|
What happens when a plant is grown on a rotating drum in the dark? |
The shoot and roots grow straight |
|
|
How are fruits brought from the source to the consumer and what processes do they go through? |
The unripe fruits are cooled and transported to reduce damage They are then exposed to ethene gas so it ripens quicker |
|
|
How are auxins used in commercial use? |
Used in the production of seedless fruits Used in rooting powder to stimulate root growth from cuttings Synthetic auxins act as weed killers that are selective to dicots and non-toxic to animals |
|
|
What can cytokinins be used for? |
To help prevent ageing of ripe fruit (Cytokinesis prevents you from growing old as you can see into the future) |
|
|
What can gibberellins be used for in the industry? |
Delay ripening fruit so they can become bigger (Gibberellins make things big like giants and slow) |
