Plant

Question 1

Stomata

Answer 1

Stomata are gaps in the lower epidermis of leaves that facilitate (make easier) the diffusion of gases, including evaporated water, in and out of the leaf.

Question 2

Guard cell

Answer 2

Guard cells can open and close the stomata.

The guard cells can open the stomata by taking up lots of water, causing them to swell.

To close the stomata the guard cells lose water and return to a limp state

Question 3

Why do stomata close at night?

Answer 3

Time of day affects the state of stomata.
At night, they close because, in the absence of sunlight, carbon dioxide is not required for photosynthesis.
At this time, their only objective is to prevent water loss.

Question 4

What is transpiration ?

Answer 4

Transpiration transports water and the minerals dissolved in it through the plant.

Water moves in one direction only: from the roots to the leaves.

Method of transport : in xylem

Xylem are dead hollow tube

Question 5

Air flow

Answer 5

Increased air flow carries water away from the plant’s leaves, encouraging more water to evaporate.
Increased air flow increases the rate of transpiration.

Question 6

Light intensity

Answer 6

Increased light intensity makes water evaporate faster, which increases the rate of transpiration.

Question 7

Humidity

The concentration of water vapour in the air

Answer 7

Increased humidity increases the amount of water in the air. This makes it more difficult for more water to evaporate.
Increasing humidity decreases the rate of transpiration.

Question 8

Temperature

Answer 8

Increased temperature makes water evaporate faster, which increases the rate of transpiration.

Question 9

When measuring the rate of transpiration with a potometer, why is the calculation only an estimate?

Answer 9

A small amount of the water taken up by the shoot is used in the leaves and is not transpired.

Question 10

Phloem

Answer 10

The phloem is specialised to transport food products to parts of the plant where they are needed. Phloem vessels are made up of columns of living cells.

The end walls of phloem cells contain small holes to allow food products to move up and down the phloem vessels throughout the plant.

Question 11

Translocation

Answer 11

Translocation is the process by which food produced in photosynthesis is transported from the leaves to the growing regions of plants and storage organs.

It’s bidirectional (goes up and down)

Transport cells are living

Transport : in phloem

Translocation is the movement of sucrose

Question 12

Phloem tubes

Answer 12

Translocation happens through phloem tubes.
They carry sucrose
Phloem tubes are made up of columns of elongated cells that have holes in the end walls.
These holes allow cell sap (a liquid in plants that stores sugars, salts and amino acids) to pass between the cells.

Question 13

Biomass

Answer 13

materials in a organism

Question 14

What is photosynthesis ?

Answer 14

Photosynthesis is process where plants and algae can trap energy from the sunlight and you it to transferred to molecule of sugar called glucose

Question 15

Is photosynthesis endothermic or exothermic ?

Answer 15

endothermic so it takes in energy

Question 16

How do plants store glucose?

Answer 16

As starch or sucrose

Question 17

Where are chloroplast found?

Answer 17

In the palisade layer because they are located at the top of the leaf where photosynthesis takes place

Question 18

What is lignin?

Answer 18

Lignin is a substance that strengthens the wall of xylem cells

Question 19

Xylem cells

Answer 19

The xylem is specialised to transport water up the stem of a plant and into the leaves.

Xylem vessels are made up of a series of connected dead xylem cells. The end walls of the cells are brocken so it allows water to move through