Gas Exchange In Plants

Question 1

What is a chloroplast

Answer 1

Part of the plant cell that is used for photosynthesis

Question 2

What is chlorophyll

Answer 2

A green compound that absorbs light

Question 3

What is an epidermis

Answer 3

Thin layer of cells (top + bottom)

Question 4

What does the phloem do

Answer 4

Transport sugars around the plant

Question 5

What does the xylem do

Answer 5

Transports water + mineral ions around the plant

Question 6

What is respiration

Answer 6

A process which uses glucose to make energy

Question 7

What are stomata

Answer 7

Minute pores which open to allow co2 to diffuse into the leaf

Question 8

What is the function of the vein

Answer 8

To transport xylem and phloem and support the leaf

Question 9

Which cell contains chloroplasts

Answer 9

Palisade cell

Question 10

Which part of the plant contains chloroplasts

Answer 10

Chlorophyll

Question 11

Where are the xylem and the phloem cells contained

Answer 11

Veins

Question 12

What is transpiration

Answer 12

The process by which water vapour is lost from leaves

Question 13

There are lots of stomata on the _________ surface of the lower epidermis. Why?

Answer 13

Upper surface because otherwise they lose water

Question 14

____________ triggers the movement of minerals into the guard cells. This makes water move into the guard cells by __________. As water moves in, the guard cells become swollen or ‘________’ and the cell bends because the inner cell wall is thicker making the stomata _______

Answer 14

Sunlight
Osmosis
Turgid
Open

Question 15

In the dark, water _________ the guard cells and they become ____________ making the stomata ____________

Answer 15

Leaves
Flaccid
Close

Question 16

What is transpiration

Answer 16

The loss of water by evaporation through the stomata.

It is a side-effect of the way leaves are adapted for photosynthesis

Question 17

Either side of the stomata are 2 banana-shaped _________ cells

Answer 17

Guard cells

Question 18

The part of the cell wall nearest to the stoma is __________ than the cell wall elsewhere in the cell. As the guard cell becomes more turgid, this uneven thickness of cell wall causes the cell to bend outwards which opens the _________

Answer 18

Thicker

Stomata

Question 19

In the light, water ________ the guard cells by osmosis from the surrounding epidermis cells

Answer 19

Enters

Question 20

In the light, the guard cells use energy to accumulate solutes in their _________ which causes water to be drawn into them by osmosis

Answer 20

Vacuoles

Question 21

Name the equipment that can be used to measure the rate of transpiration

Answer 21

Potometer

Question 22

Transpiration is the evaporation of _______ from leaves. It escapes through tiny pores called __________

Answer 22

Water

Stomata

Question 23

How does light affect the rate of transpiration and why

Answer 23

It increases because the stomata open wider to allow more carbon dioxide into the leaf for photosynthesis

Question 24

How does high temperature affect the rate of transpiration and why

Answer 24

It is faster in higher temperatures because evaporation and diffusion are faster at higher temperatures

Question 25

How does wind affect the rate of transpiration and why

Answer 25

It is faster in windy conditions because water vapour is removed quickly, so more water vapour diffuses out of the leaf

Question 26

What will happen to the rate of transpiration if it is humid

Answer 26

It is slower because diffusion of water vapour out of the leaf slows down if the leaf is already surrounded by moist air

Question 27

Why is transpiration important

Answer 27

- It supplies water for the leaf cells to carry out photosynthesis - Carries mineral ions dissolved in water - Provides water to keep the plant cells turgid - Allows evaporation form the leaf surface which cools the leaf, in a similar way that sweat cools the human skin

Question 28

Inside a plant, water moves from cell to cell by __________

Answer 28

Osmosis

Question 29

The long thin outer projection of the _____ ______ cells penetrates between the soil water particles, reaching the soil water. The soil water has a a higher potential than the inside of the cell which allows water to enter the cell by ___________

Answer 29

Root hair cells | Osmosis

Question 30

Water leaves the cells of the leaf mesophyll and evaporates into the air spaces between the _________ _____________ cells

Answer 30

Spongy mesophyll cells

Question 31

Why is it important that root hair cells have a large surface area

Answer 31

It means that more mineral ions can be diffused into it - efficient absorption

Question 32

What does the term partially permeable mean

Answer 32

Will allow certain solutes (e.g water) through

Question 33

Suggest a reason for the large numbers of mitochondria present in cells involved in active transport

Answer 33

Make energy for respiration

Question 34

_____________ are not found in all plant cells. For example, they are not found in root hair cells

Answer 34

Chloroplasts

Question 35

What colour does hydrogen-carbonate indicator if there are high levels of Co2

Answer 35

Yellow

Question 36

What colour does hydrogen-carbonate indicator if there are low levels of Co2

Answer 36

Purple

Question 37

What colour does hydrogen-carbonate indicator if there are normal levels of Co2

Answer 37

Red

Question 38

Word equation for photosynthesis

Answer 38

Carbon dioxide + Water --> Glucose + Oxygen

Question 39

Symbol equation for photosynthesis

Answer 39

6CO2 + 6H2O --> C6H12O6 + 6O2

Question 40

How are leaves adapted for photosynthesis (3)

Answer 40

Large surface area Chloroplasts on palisade layer Upper epidermis is transparent Thin for gas exchange

Question 41

What is a limiting factor

Answer 41

Something which stops photosynthesis from happening any faster

Question 42

Palisade mesophyll layer

Answer 42

These have the most chloroplasts - where most photosynthesis takes place

Question 43

Spongy mesophyll layer

Answer 43

Cells with big air spaces around them for gas exchange

Question 44

Waxy cuticle

Answer 44

A transparent, waterproof layer that lets light through. Water runs off it. It also acts as a barrier to the entry of disease causing microorganisms

Question 45

Upper epidermis

Answer 45

Like the cuticle Single, transparent, layer of cells with no chloroplasts - allows sunlight through to the epidermis where there are chloroplasts

Question 46

Vascular bundle

Answer 46

Transport vessels of xylem and phloem

Question 47

Lower epidermis

Answer 47

Has lots of tiny holes called stomata which allow gases to diffuse in and out

Question 48

Guard cell

Answer 48

A pair of curved cells that surround a stoma

Question 49

How are leaves adapted for efficient gas exchange

Answer 49

Broad leaves Thin leaves Air spaces inside leaf Stomata on lower surface for gas exchange

Question 50

What will a plant do if there is a lack of water from the roots

Answer 50

``` Stop photosynthesising (bad) But if they didn't, the plant might dry out and die (worse) ```