Germination and Plant Hormones

Question 1

Required practical equipment

Answer 1

White mustard seeds
Petri dishes
Cotton wool
Ruler
Water
Access to windowsill
Access to dark cuboard

Question 2

Control variables for germination

Answer 2

Type of seed
Volume of water
Number of seeds
Temperature
Time

Question 3

Dependent variable

Answer 3

Height of seeds

Question 4

Independent variable

Answer 4

Light intensity

Question 5

What is resolution

Answer 5

Smallest measurement eg 1 mm with ruler

Question 6

Repeatability is

Answer 6

You repeat it
Same method
Similar results

Question 7

Reproducibility is

Answer 7

Someone else
Different method
Similar results

Question 8

Why do we need reproducibility, repeatability and resolution

Answer 8

reliability

Question 9

If results are valid they can be

Answer 9

Repeated(also gets rid of anomalies)and compares

Question 10

Required practical

Answer 10

-Set up petridishes with cotton wool soaked in equal amounts of water
-Place in a warm place where they aren’t disturbed
-Allow seeds to germinate and add more water when needed
-make sure number of seedlings is the same
-place one on windowsill in full sunlight
-place one in dark cupboard
-place one in partial light
Measure height everyday for a week and record the results for each in different tables
-calculate mean height + draw a height in time graph

Question 11

Charles Darwin investigated tropism

Why does one shoot bend towards the light

Answer 11

• Unequal distribution of hormone (auxin) found in the meristem
• more auxin released on dark side
• causes growth (cell elongation) on dark side

Question 12

Where is light stimulus detected in phototropism experiment

Answer 12

Tip of seedling

Question 13

Geotropism/gravatropism meaning
+geotropism
-geotropism

Answer 13

Growth of plants in response to gravity
+geotropism is downwards growth of plant shoots
-geotropism is upwards growth of plant shoots

Question 14

Hydrotropism

Answer 14

Growth in response to water

Question 15

How does phototropism help a plant survive

Answer 15

Leaves/plant absorbs more light
More photosynthesis
Plant produces more glucose

Question 16

Geotropism in roots
A is stationary
B rotates
Why does B rotate

Answer 16

Cancel out effect of gravity

Question 17

Explain how the hormone auxin causes a different in appearance of 2 seedlings eg A (bent downwards) and B(straight)

Answer 17

Uneven distribution of hormone(auxin) in A
Even distribution of hormone(auxin) in B
So more cell elongation on top of a
And equal growth in B

Question 18

Auxin use

Answer 18

Stimulates plant growth

Question 19

Ethene use

Answer 19

Ripens fruit

Naturally found in bananas

Question 20

Gibberellin

Answer 20

Increase fruit size
Control seed dormancy-germination
Promotes flowering

Question 21

How to measure curved seedling

Answer 21

Use thread
Or
Straighten and use ruler