Question 1

The following passage outlines the process of phototropism in plants:

'Auxin is synthesised in cells at the ............ of the shoot. Auxin causes the cells to ............ on one side, so the stem bends.

Scientists originally thought auxin was ............ by light but this was disproved by the fact that plants growing in the dark and plants growing in unilateral light had ............ auxin levels.'

What is the correct sequence of missing words?

  A  

meristem, shorten, destroyed, different

  B  

tip, elongate, destroyed, similar


  C  

meristem, shorten, synthesised, raised

  D  

tip, elongate, synthesised, similar

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Question 2

Which statement provides evidence for geotropism?

  A  

leaves are shed from deciduous plants in the autumn

  B  

roots grow downwards

  C  

shoots grow towards the light

  D  

flowers can change position throughout the day

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Question 3

Many trees drop their leaves in the autumn.

Which plant hormone(s) is/are thought to be involved in the control of leaf drop?

   1 - auxin

   2 - ethene

   3 - gibberellin

  A  

1, 2, and 3

  B  

only 1 and 2

  C  

only 2 and 3

  D  

 only 1

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Question 4

Which plant hormone is known to stimulate seed germination and stem elongation?

  A  

auxin

  B  

gibberellin

  C  

ethylene

  D  

cytokinin

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Question 5

What is the role of gibberellins in seed germination?

  A  

they inhibit the growth of the seed embryo

  B  

they stimulate the closing of stomata

  C  

they stimulate the production of enzymes that break down food stores

  D  

they promote the synthesis of protective seed coats

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Question 6

What effect do auxins have on the growth of plant shoots?

  A  

they prevent cell elongation

  B  

they stimulate seed germination

  C  

they promote cell elongation

  D  

they induce flower blooming

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Question 7

How does the removal of the apical bud affect plant growth?

  A  

it allows lateral shoots to grow faster due to reduced auxin concentration

  B  

it promotes the development of the apical bud

  C  

it causes the plant to lose turgor pressure

  D  

it leads to the immediate wilting of the plant

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Question 8

What is the effect of auxin on the pH in the cell wall?

  A  

it increases the pH, making the cell wall more rigid

  B  

it decreases the pH, increasing cell wall plasticity

  C  

it has no impact on the pH of the cell wall

  D  

it neutralises the pH, preventing cell elongation

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Question 9

How do high concentrations of auxins affect lateral shoot growth in plants?

  A  

they stimulate rapid growth of lateral shoots

  B  

they suppress the growth of lateral shoots

  C  

they have no effect on lateral shoots

  D  

they cause lateral shoots to flower

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Question 10

How do plant hormones affect apical dominance?

  A  

by promoting root growth over shoot growth

  B  

high concentrations of auxins suppress the growth of lateral shoots

  C  

by triggering the germination process

  D  

by inducing the flowering of the plant

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Question 11

Which process is directly activated by the presence of auxins in the cell wall?

  A  

synthesis of gibberellins

  B  

synthesis of abscisic acid

  C  

activation of expansins that loosen the cell wall

  D  

immediate seed germination

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