OCR A LEVEL BIOLOGY: Plant Responses, Module 5

Question 1

How are gibberellins involved in plant breeding?

Accepted Answer

Inhibitition causes flowers to form desired characteristics, Speeds up seed formation

Question 2

What do gibberellin promote?

Accepted Answer

Stem growth, Seed germination

Question 3

How are gibberellins involved in sugar production?

Accepted Answer

Stem elongation

Question 4

How can you override apical dominance?

Accepted Answer

Cytokinins applied to buds and removal of apex

Question 5

True or false - ethene promotes fruit ripening

Accepted Answer

True

Question 6

Which of these plants would not be influenced by phototropism?

Accepted Answer

Tip separaed by mica

Question 7

What is a non-directional response to an external stimulus called?

Accepted Answer

Nastic responses

Question 8

True or false - auxins cause cells to stop growing

Accepted Answer

False - they promote cell elongation

Question 9

Cytokinins do not overcome apical dominance, true or false?

Accepted Answer

False - they do overcome apical dominance

Question 10

True or false - auxins can inhibit cell elongation?

Accepted Answer

True - depends on what part of the plant

Question 11

Which of these is a commercial use of auxins?

Accepted Answer

Weed killer, Promote seedless fruit growth, Rooting powder

Question 12

What does cytokinins promote?

Accepted Answer

Cell division and expansion

Question 13

How do hormones move around the plant?

Accepted Answer

All the answers

Question 14

What does abscisic acid inhibit?

Accepted Answer

Seed germination and growth

Question 15

How can we investigate geotropism?

Accepted Answer

Slowly rotate plants grown on their side

Question 16

How are gibberellins involved in brewing?

Accepted Answer

Speeds up seed germination

Question 17

Tannins, alkaloids, and pheromones are all examples of what?

Accepted Answer

Chemical defences in plants

Question 18

How do auxins regulate plant growth?

Accepted Answer

Plant tip removal causes growth of lateral buds, Prevents lateral bud growth, Auxin in apical buds inhibits lateral bud growth, Causes apical dominance

Question 19

Where in a plant does growth occur?

Accepted Answer

Lateral meristems (roots and shoots), Intercalary meristems between nodes (shoots), Apical meristems at the tips or apex (roots and shoots), Lateral bud meristems in buds (side shoots)

Question 20

What do cytokinins delay?

Accepted Answer

Leaf senescence

Question 21

True or false - abscisic acid causes stomatal closure

Accepted Answer

True

Question 22

Which of these are an example of tropism?

Accepted Answer

Phototropism - directional growth towards light, Thigmotropism - growth to maintain support, Chemotropism - directional growth due to chemicals, Geotropism - directional growth due to gravity

Question 23

What is a positive tropic?

Accepted Answer

Response towards the stimulus

Question 24

What is a commercial use of cytokinins?

Accepted Answer

Tissue culture to mass produce plants, Prevents yellowing of lettuce leaves

Question 25

How does auxin cause its effect?

Accepted Answer

Increases stretchiness of cell wall, Alters pH for optinum conditions for enzymes, Promotes H+ pumping through ATP synthase through membrane, Hydrogen bonds in cellulose break, loosening the wall

Question 26

How are gibberellins involved in fruit production?

Accepted Answer

Fruit elongation, Delay senescene in citrus fruits

Question 27

What is apical dominance?

Accepted Answer

Inhibition of lateral buds

Question 28

Which of these are false about ethene?

Accepted Answer

Inhibits lateral growth in plants, making straight flowers

Question 29

What do auxins inhibit?

Accepted Answer

Leaf abscission, Growth of side shoots

OCR A LEVEL BIOLOGY: Plant Responses, Module 5

Questions 29

OCR A LEVEL BIOLOGY: Plant Responses, Module 5

Questions 29