Biology CH:24 Transport, storage and Gas exchange in Flowering Plant

Question 1

What are Autotroph

Answer 1

Organisms that make their own food are said to be autotrophic

Question 2

What is a root hair and where is it located?

Answer 2

Root hair are extensions of root epidermis cells and are found near the tip of small roots

Question 3

Adaptation of root hair for absorption

Answer 3

1) Thin walls
2) Not covered by a cuticle
3) Very numerous, which provides a larger surface area

Question 4

How does water absorb into root hair?

Answer 4

The absorption of water into root hairs takes place by osmosis

Question 5

Why does the water absorbs into root hair rather than give up into soil?

Answer 5

The cytoplasm of root hair is more concentrated by dissolved solutes than water in the soil

Question 6

How does the water will be carried further?

Answer 6

Water diffuse from root hair cells across ground tissue until it reaches the xylem.

Question 7

Upward movements of water
(Two mechanisms)

Answer 7

The two movements of water from the roots to the upper parts of a plants are
1. root pressure
2. transpiration

Question 8

Root pressure

Answer 8

The build up of water that is drawn into roots by osmosis causes a pressure which pushes water up through the xylem
(Root pressure is not strong enough to push water to the top of very high plants)

Question 9

Transpiration and where does it take places?

Answer 9

Is the loss of water vapour (by evaporation) from leaves and other aerial parts of a plants
Transportation take place through opening called stomata

Question 10

How does transpiration work?

Answer 10

Water evaporates from the cells in the leaf into the air spaces. From the air space it diffuses out into the atmosphere through the stomata.

Question 11

Control of Transpiration in leaves

Answer 11

1. Leaves have a waxy cuticle through which water cannot pass. (Cuticle does not cover stomata in the lower surface of the leaf)
2. Stomata typically located on the lower surface of the leaf hence its not under direct sunlight so it is cooler. This helps to reduce water loss by transpiration
3. Each stomata are surrounded by two guard cells. Normally stomata open by day to exchange gases for photosynthesis and close at night because there is no photosynthesis at night which will prevent water loss.

Question 12

Mineral Uptake and transport

Answer 12

1. Some of the minerals are absorbed by Diffusion which doesn’t need energy (called passive transport)
2. Some of the minerals are absorbed by active transport which use energy in the form of ATP

Question 13

Two sources of CO2 for photosynthesis

Answer 13

1. Most CO2 comes in through the stomata from the atmosphere
2. Some of the CO2 are produced in leaf cells by the process of respiration.

Question 14

**True Rate of photosynthesis **=

Answer 14

Rate of CO2 absorbed Through the stomata + Rate of CO2 produced in respiration