Transport, Storage and Gas Exchange Of Flowering Plants

Question 1

Autotroph

Answer 1

Makes it’s own food

Question 2

Why do plants need a transport system?

Answer 2

To provide materials needed for various plant metabolic processes including photosynthesis, respiration etc..

Question 3

What is transported?

Answer 3

• Water
• Carbon dioxide
• Minerals
• Carbohydrates produced by Photosynthesis

Question 4

Water uptake

Answer 4

Water enters the root hair cells by osmosis. Root hairs are adapted by having thin walls and being so numerous so there is a large surface area.

Question 5

Water movement through the root

Answer 5

Water moves by osmosis from the root hairs into the ground tissue from cell to cell until it reaches the xylem

Question 6

Upward movement of water
- Root pressure

Answer 6

As water moves into the root by osmosis it builds up a pressure that pushes (forces) water up the xylem

Question 7

Upward movement of water
- Transpiration

Answer 7

As water evaporates from the lead by transpiration, more water is pulled upwards through the xylem into the leaf.

Question 8

Control of water loss from leaf
- Presence or absence of cuticle

Answer 8

Water cannot pass through the cuticle. The presence of a cuticle helps reduce excessive water loss.

Question 9

Control of water loss from the leaf
- Opening & closing of stomata

Answer 9

Stomata opening increases water loss
Stomata closing reduces water loss

Question 10

Control of water loss from the leaf
- Location of the stomata

Answer 10

Stomata are normally located on the lower surface of the leaf because it’s not in direct sunlight and it’s cooler. This helps reduce water loss by transpiration

Question 11

Mineral uptake & transport

Answer 11

Some minerals are taken up by diffusion and some by active transport.

Question 12

C02 sources

Answer 12

1. Diffuses from the air in through the stomata
2. Produced in the plant by respiration

Question 13

Glucose fate

Answer 13

Used in respiration to provide energy for the plant. Glucose can be converted into starch for long term food storage. Starch & glucose transported around the plant in the phloem.

Question 14

Modified root (food storage)

Answer 14

Carrot
Dicot plants

Question 15

Modified stem

Answer 15

Potato

Question 16

Modified leaves

Answer 16

Onion bulbs
(Swollen by starch)

Question 17

Gas exchange

Answer 17

In the stem, lenticles allow for gas exchange, carbon dioxide diffuses into air spaces on the ground tissue and then into cells. Oxygen diffuses from ground tissue into air. Water vapour leaves in same way

Question 18

Cohesion

Answer 18

Similar molecules sticking together e.g water molecules sticking to water molecules

Question 19

Adhesion

Answer 19

Different molecules sticking together e.g water molecules sticking to the xylem

Question 20

The cohesion - tension model
Overview

Answer 20

Check notes. I’m too tired to write out this bullshit..

Question 21

Stomatal opening & closing

Answer 21

Guard cells open and close (stoma) stomata. When water enters the guard cells by osmosis they become turgid/swollen. As the cells are joined at tips, they increase in size, buckle outwards, therefore opening stoma. When they lose water they shrink and close.

Question 22

Control of stomatal opening and closing

Answer 22

• The major factor is the concentration of carbon dioxide in the air spaces of the leaf.
• High concentration = Stomata close = night (respiration)
  Low concentration = stomata open = Day (photosynthesis)