Plant Structures and their functions

Question 1

In what part of a cell does photosynthesis take place?

Answer 1

Chloroplasts

Question 2

Apart from water vapour, what gas is needed for photosynthesis?

Answer 2

Carbon dioxide (CO2)

Question 3

Name the two products of photosynthesis

Answer 3

Glucose and Oxygen

Question 4

Why is photosynthesis described as an endothermic reaction?

Answer 4

Because it takes in energy to make the reaction work

Question 5

What effect would a low carbon dioxide concentration have on the rate of photosynthesis?

Answer 5

It would slow down the reaction

Question 6

What effect would a temperature above 45C usually have on the rate of photosynthesis?

Answer 6

It would make the reaction slow or stop as plants cannot photosynthesize at high temperatures

Question 7

What is the relationship between light intensity and distance from a light source?

Answer 7

Light intensity = 1/distance(d)2

Question 8

What is the relationship between light intensity on the rate of photosynthesis?

Answer 8

The higher the light intensity, the higher the rate of photosynthesis.

Question 9

What is a limiting factor?

Answer 9

A limiting factor is a factor which limits the rate at which a chemical reaction occurs

Question 10

What are the limiting factors for photosynthesis?

Answer 10

Amount of carbon dioxide, light intensity and temperature.

Question 11

What does the relationship between temperature and rate of photosynthesis look like on a graph?

Answer 11

The rate of photosynthesis would increase up to a certain point and then begin to drop down to 0

Question 12

What does the relationship between amount of carbon dioxide and rate of photosynthesis look like on a graph?

Answer 12

The rate of photosynthesis would increase up to a point and then form a plateau

Question 13

What does the relationship between light intensity and rate of photosynthesis look like on a graph?

Answer 13

The rate of photosynthesis would increase up to a point and then form a plateau

Question 14

How are root hair cells adapted to their function?

Answer 14

They have a large surface area to absorb water and nutrients

Question 15

By what process do phloem tubes transport sucrose around a plant?

Answer 15

Active transport

Question 16

Describe the structure of xylem vessels

Answer 16

Xylem vessels are long hollow chains of tough long dead xylem cells.

Question 17

What are stomata?

Answer 17

Tiny pores on the surface of a plant, found mostly on the underside of the leaves

Question 18

What is the role of stomata in transpiration?

Answer 18

They allow the water vapour to escape from the plant

Question 19

Give three factors that affect the rate of transpiration

Answer 19

Light intensity, temperature and air flow.

Question 20

What can you use to measure the rate of transpiration?

Answer 20

Potometer

Question 21

Calculate the rate of transpiration if the distance moved by the bubble is 50mm and it took 20seconds to move.

Answer 21

2.5mm/sec-1

Question 22

Name, in order from top to bottom, the layers of a leaf.

Answer 22

Waxy Cuticle
Upper epidermis
Palisade mesophyll tissue
Spongy mesophyll tissue
Lower epidermis
Waxy Cuticle

Question 23

Which layer has the most choloplasts?

Answer 23

Palisade mesophyll tissue

Question 24

Name 3 adaptations that plants have to live in desert conditions.

Answer 24

Small leaves or spines
Curled leaves or hairs
Thick waxy cuticle
Thick fleshy stem that stores water
Fewer stomata that only open at night
Stomata sunken in pits

Question 25

Where is auxin found in a plant?

Answer 25

In the tips of shoots.

Question 26

What does auxin promote?

Answer 26

Cell elongation

Question 27

Why do plants have auxins?

Answer 27

To be able to move nearer or further away from the sun.

Question 28

What parts of a plant are positively phototrophic?

Answer 28

Shoots

Question 29

What parts of a plant are negatively phototrophic?

Answer 29

Roots

Question 30

What parts of a plant are positively gravitrophic?

Answer 30

Roots

Question 31

What parts of a plant are negatively gravitrophic?

Answer 31

Shoots

Question 32

What hormones are used for selective weedkillers?

Answer 32

Auxins

Question 33

What hormones are used for rooting powder?

Answer 33

Auxins

Question 34

What hormones are used for controlling flower and fruit formation?

Answer 34

Gibberlins

Question 35

What hormones are used for Producing seedless fruit?

Answer 35

Gibberlins

Question 36

What hormones are used for Controlling fruit ripening?

Answer 36

ethene

Question 37

What hormones are used for controlling seed germination?

Answer 37

Gibberlins