21 - Plant Communication and Defence Flashcards Preview

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Flashcards in 21 - Plant Communication and Defence Deck (15)
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1
Q

Plants are very vulnerable to attack because they are sessile. What does sessile mean?

A

They can’t move.

2
Q

What defence mechanism does a trifolium plant use?

A

Release poisonous cyanide gas

3
Q

How do plants search for areas of nutrient-rich patches?

A

They send out their rhizomes/runners

4
Q

Mustard plants produce trichome. What does this do?

A

Trichomes are small leaf hairs to prevent insects from eating the leaves.

5
Q

What are secondary chemicals?

A
Secondary chemicals are those that are not directly involved in the normal growth/reproduction of an organism. Rather, they are released when they are attacked. Examples are:
o	Tannins
o	Polyphenols
o	Nicotine
o	Glycosides
o	Alkaloids
o	Nepetalactone
6
Q

What do Tannins in plants do?

A

Tannins are a chemical that binds to the protein so the animal can’t benefit from it.

7
Q

What is the difference between Cyanogenic and Acyanogenic plants?

A

Cyanogenic plants - release cyanide (defence mechanism)

Acyanogenic plants - don’t

8
Q

What do acyanogenic plants do when herbivores are present, considering they don’t have a defence mechanism.

A

They sexually reproduce more.

9
Q

Methyl Jasmonate and Ethylene are released from damaged plant tissue. Why?

A

They let the plant know they are being attacked.

10
Q

Apart from chemical signals, how else can plants know they are being attacked?

A
  • They can detect chewing on tissue (experimentally tested by subjecting the plants to caterpillar eating noises)
  • They can detect herbivore saliva
11
Q

True or false. Plant responses to attack are the same for any herbivore that attacks it.

A

False. Plant responses can be tailored to a specific herbivore. For example, tobacco and the hawk moth.

12
Q

Tobacco plants are pollinated by moths at dusk, but they are also eaten by these moths. What did the tobacco plants do to prevent their pollinator from being a predator?

A

Instead of opening up during dusk, they open up during the day to be pollinated by hummingbirds

13
Q

True or false? Plants that are under attack can let other plants near it know that they are being attacked.

A

True. The nearby plants will start releasing their defence mechanisms.

14
Q

What do sugar maple trees do every few years to avoid their seeds being consumed by squirrels?

A

They release a massive amount of seeds to ensure a greater chance of survival.

15
Q

Plants can also attack when other plants are all up in their space. What does the spotted knapweed do in this instance?

A

It releases catechin in the presence of roots of another species. This is taken up by the roots of the other plant and leads to a cascading physiological and genetic response where the competing plant dies within a few days.