Plantsss

Question 0

Hydrotropism in shoots

Answer 0

None

Question 1

What is a tropism

Answer 1

The growth response of a plant to a directional stimulus

Question 2

Hydrotropism in roots

Answer 2

Some grow towards direction of water (positive hydrotropism)

Question 3

Phototropism in shoots

Answer 3

Grow towards light source (positive phototropism

Question 4

Phototropism in roots

Answer 4

Most species show no response; some grow away from light (negative phototropism)

Question 5

Geotropism in shoots

Answer 5

Grow against direction of gravity (negative geotropism)

Question 6

Geotropism in roots

Answer 6

Grow towards direction of gravity (positive geotropism)

Question 7

What is auxin

Answer 7

The hormone(plant growth substance) that is responsible for tropism

Question 8

Why does a lack of nitrogen inhibit he growth of a plant

Answer 8

Nitrate ions needed For making amino acids which make proteins which are required for growth

Question 9

Why are phosphate ions needed by plants

Answer 9

Making DNA

A plant deficient in phosphate will have poor root growth and younger leaves will turn purple

Question 10

Why are potassium ions needed by plants

Answer 10

Needed for enzymes of respiration and photosynthesis to work

In plants lacking potassium, leaves turn yellow with dead spots

Question 11

Why are magnesium ions needed by plants

Answer 11

Magnesium is needed for making chlorophyll for photosynthesis
The colour of this pigment is green and so plants that lack magnesium have yellow leaves

Question 12

Why is starch a good way of storing carb

Answer 12

Not soluble
Compact
Can be broken down easily

Question 13

Why can’t you test a fresh leaf for starch using iodine

Answer 13

The waxy surface won’t absorb the solution

Green colour of leaf masks colour change

Question 14

How do you remove the outer waxy layer and decolorise a leaf

Answer 14

Place it in boiling ethanol

Question 15

How can you de starch a leaf

Answer 15

Place it in the dark for 2 or 3 days

The plant uses up the starch stores in its leaves

Question 16

How to stop co2 from getting to a plant

Answer 16

Place the plant in a closed container containing a chemical called soda lime - this absorbs co2 from the air around the plant

Question 17

What does a clinostat do

Answer 17

Holds the plant and slowly rotates in a vertical plane, so that the movement eliminates any directional stimulus that may be acting on the seeds

Question 18

Guard cell adaptation for function

Answer 18

‘Banana’ shape with thicker cell wall on inside (around) means that when the guard cells become turgid they change shape, bowing outwards, so opening the stoma for gas exchange

Question 19

Only cells that don’t need osmosis to maintain their shape

Answer 19

Xylem cells

Question 20

preventing water loss by having stomata in sunken pits in leaf

Answer 20

A region of humid air is trapped in the pit

This reduces evaporation through the stomata, conserving water in the plant

Question 21

Lipids uses

Answer 21

Energy store in some plants eg nuts, seeds

Part of all cell membranes