Additional: Scientific Processes (Unit 304)

Question 1

What is the purpose of photosynthesis in plants?

Answer 1

To prouduce glucose (food) using light energy

Question 2

What is the word equation for photosynthesis?

Answer 2

Carbon dioxide + Water => Glucose + Oxygen

Question 3

Which part of the cell contains chlorophyll for photosynthesis?

Answer 3

The chloroplasts

Question 4

How does the light intensity affect the rate of photosynthesis?

Answer 4

Higher light intensity increases the rate until it reaches a maximum

Question 5

Why is carbon dioxide essential for photosynthesis?

Answer 5

It is a raw material used to make glucose

Question 6

Define Osmosis

Answer 6

The movement of water from a high water concentration to a low water concentration through a partially permeable membrane.

Question 7

Why is osmosis important in maintaining plant turgor?

Answer 7

It keeps cells swollen and firm, supporting the plants structure.

Question 8

Define Turgor

Answer 8

The normal state of how hard a cell is, caused by its contents pressing against the cell wall

Question 9

What happens to a plant cell placed in a strong salt solution?

Answer 9

Water leaves the cell causing it to shrink and become plasmolysed.

Question 10

Define Plasmolysed

Answer 10

The situation in which protoplasm (= clear liquid in all living cells) shrinks back from cell walls because of lack of water

Question 11

How do root hair cells use osmosis to absorb water?

Answer 11

Water enters because the root hair cells have a lower water concentration than the soil.

Question 12

What is the difference between osmosis and diffusion?

Answer 12

Osmosis is only water and needs a membrane; diffusion can be any particles and doesn’t require a membrane.

Question 13

What is the word equation for aerobic respriation in plants?

Answer 13

Glucose + Oxygen => Carbon dioxide + Water + Energy

Question 14

When does respriation occur in plants?

Answer 14

Both day and night

Question 15

Why do plants need respiration even though they photosynthesize?

Answer 15

To release energy for growth, repair, active transport ect.
(Same how we need a knife and fork when we have food)

Question 16

What is the energy (from respiration) used for?

Answer 16

• Cell division
• Active transport
• Movement of substances
• Growth
• Metabolic processes

Question 17

What is the difference between aerobic and anaerobic respiration?

Answer 17

Aerobic uses oxygen and releases more energy. Anaerobic produces less energy and doesn’t use oxygen.

Question 18

Define Transpiration

Answer 18

The loss of water vapour from leaves through stomata

Question 19

Define Stomata

Answer 19

Plant pores on the leaf or stem through which gases are able to pass in and out.

Question 20

What are the environmental factors that increase the rate of transpiration?

Answer 20

• Heat
• Wind
• Low humidity
• Light

Question 21

How does transpiration help transport water through the xylem?

Answer 21

It creates a pull/transpiration stream that draws up water through the roots.

Question 22

Define Xylem

Answer 22

Plant tissue that carries water and minerals from the roots to the leaves and gives support to the stem or trunk

Question 23

Why do plants close their stomata on hot, dry days?

Answer 23

To reduce water loss and prevent wilting

Question 24

How are transpiration and photosynthesis linked?

Answer 24

During photosynthesis the open stomata let out carbon dioxide but this allows water vapour out causing transpiration

Question 25

What factors affect the rate of photosynthesis?

Answer 25

* Availability of light * Availability of water to the roots * Amount of carbon dioxide in the air * Temperature * Supply of mineral nutrients.