Gas Exchange and Transport in Plants

Question 1

What does turgid mean

Answer 1

This is when the plant cell is full of water. This causes the vacuole to swell up and the cytoplasm pushes against the cell wall.

Question 2

What is the xylem

Answer 2

Carries water and minerals up from the root

Question 3

Is the xylem made of dead or alive cells

Answer 3

Dead

Question 4

What is the phloem

Answer 4

Carries products of sucrose (food) away from the leaves. The content can travel up or down the plant to a food storage place.

Question 5

What is the vascular bundle

Answer 5

This is were the xylem and phloem are grouped together in a young stem.

Question 6

What are guard cells

Answer 6

These so round each stomata and become placid or turgid in order to open or close. At night the stomata will close as no photosynthesis will be occurring. This prevents the plant loosing water.

Question 7

What is a potometer

Answer 7

A simple piece of apparatus which measures the rate of transpiration or the the rate of water uptake by a plant

Question 8

What is the definition for active transport

Answer 8

This is were ions are moved from a low to high concentration through a semi permeable membrane by protein carriers. this requires energy in the form of ATP.

Question 9

What is hydrocarbon ate indicator

Answer 9

This is used to show carbon dioxide concentration in a solution. It will go yellow to purple
High to Low

Question 10

What is the word equation for photosynthesis

Answer 10

Carbon dioxide + water = oxygen + glucose

Question 11

what is the symbol equation for photosynthesis

Answer 11

6CO2 + 6H2O = C6 H12 O6 + 6O2

Question 12

What is the definition for respiration

Answer 12

Glucose from food is broken down to release energy and produce carbon dioxide + water

Question 13

Where are the stomata found

Answer 13

On the underside of the leaf

Question 14

What does hypertonic mean

Answer 14

Low water concentration.

Water moves out of the cell. Cytoplasm pulls away from the cell wall. The cell is plasmolyse.

Question 15

What is Isotonic

Answer 15

Same water concentration as usual.

No net moment of water.

Question 16

What does hypotonic mean

Answer 16

High water concentration.

Water moves into the cell. cytoplasm is pushing against the cell wall. The cell is turgid.

Question 17

Why does the respiration rate never change

Answer 17

Because the levels of oxygen and carbon dioxide never change, so respiration can go at a constant rate.

Question 18

What mineral ions does a plant need and what does it need them for

Answer 18

Magnesium is needed to make chlorophyll which is vital for photosynthesis.
Nitrates produce protein which is needed to make the plant grow.

Question 19

Where does respiration take place

Answer 19

The mitochondria

Question 20

Giv e two adaptions the root hair cell has and why

Answer 20

No chloroplast as there is no light

Lots of mitochondria for energy production

Question 21

In the vascular bundle, are the xylem on the inside or outside of the phloem

Answer 21

Inside, bigger

Question 22

How are the xylem and the phloem different

Answer 22

The xylem has a one way system as the water just needs to get up the plant. The phloem has two.

The phloem transports food substances, where as the xylem transports minerals.

Xylem cells are dead but the phloem’s are living

Xylem has thick cells (waterproof), the phloem has thin walls

Question 23

Why does the phloem have companion cells

Answer 23

To help keep them alive by giving them food

Question 24

What is the definition for transpiration

Answer 24

The evaporation of water vapour, out of the leaf, through the stomata.

Question 25

What 4 factors affect the rate of transpiration

Answer 25

Temperature
Humidity
Wind
Light

Question 26

How does temperature affect the rate of transpiration

Answer 26

More energy to evaporate the water from the stoma

Question 27

Hoe does humidity affect the rate of transpiration

Answer 27

Shallower concentration gradient

Question 28

How does light affect the rate of transpiration

Answer 28

Stoma open for photosynthesis

Question 29

How do you set up a potometer

Answer 29

A stem is inserted into a potometer underwater and sealed so that there are no air leaks
A bubble is introduced into the side arm of the apparatus. The movement of this bubble is used to estimate the amount of water lost by respiration.
The rate of movement of the bubble over a fixed distance in a set time measured.