Transport, storage and gas exchange in flowering plants

Question 1

Are plants autotroph or heterotrophs?

Answer 1

Plants are autotrophs
They make their own food by photosynthesis

Question 2

Why do plants need food?

Answer 2

For photosynthesis and other metabolic processes to occur they must take in and transport materials such as water minerals, carbon dioxide and photosynthetic products

Question 3

Define homeostasis

Answer 3

Homeostasis is the ability to maintain a constant internal environment

Question 4

Why is homeostasis important in plants?

Answer 4

It allows for enzyme activity

Question 5

Explain the role of the cuticle in relation to homeostasis

Answer 5

The cuticle prevents water loss

Question 6

What gas does the stomata control?

Answer 6

Carbon dioxide

Question 7

How is water absorbed by plants?

Answer 7

Water is absorbed by root hairs by the process of osmosis

Question 8

What adaptions do root hairs have for absorption?

Answer 8

They’ve thin walls
Not covered by a cuticle
Numerous

Question 9

Explain the process by which water moves into the root hair cell

Answer 9

Soil particles are enclosed by a layer of water called capillary water
The cytoplasm in the root hair cell contains many dissolved solute meaning that it is more concentrated than the water outside
This means that water moves by osmosis into the root hair cell
Water, then diffusers from the roots through the ground tissue and into the xylem

Question 10

What are the adaptions of the xylem for transport of water?

Answer 10

Thick walls made of lignin to support the plant
Xylem vessels are hollow on the inside
Doesn’t have mitochondria, nucleus, cytoplasm, et cetera, so is a dead vessel

Question 11

What are the two processes that enable water to move up plant?

Answer 11

Root pressure and transpiration

Question 12

What is a consequence of excessive transpiration?

Answer 12

Wilting of the plant

Question 13

What controls the rate of transpiration?

Answer 13

Stomata opening and closing by guard cells

Question 14

Explain root pressure

Answer 14

As water is pulled in by osmosis water is pushed up the stem. As more water is drawn more water gets pushed up.

The force that pushes water up the xylem from route to stem can only push up a few metres.

Question 15

What is transpiration?

Answer 15

It is the loss of water reaper from a plant. It occurs through the stomata in the epidermis of leaves and stem.

The loss of water from the leaf makes them flaccid some more water moves into the leaf cells by osmosis from the vessel to replace the lost water in this way water is pulled up the stem

Question 16

Who are the two scientist that first described the upward movement of water?

Answer 16

Dixon and joly

Question 17

Describe the upward movement of water in plants

Answer 17

Root pressure pushes water upwards in the design and cohesion of auto molecules mean they stick together. The adhesion of water molecules mean that they stick to the design of walls and then through transpiration water is pulled up the xylem tube to replace the water lost by transpiration.

Question 18

What is cohesion?

Answer 18

Cohesion is when water molecule stick together and push/pull each other along

Question 19

What is adhesion?

Answer 19

When water molecule stick to the sides of the xylem eating the push pull process

Question 20

What controls the rate of transpiration?

Answer 20

The leaves have a waxy cuticle that water can cannot pass through on the upper side
Stomata are located on the underside of the leaf as transpiration is at a lower rate here
Tomato can open and closed by Gaurd cells when necessary

Question 21

What are stomata?t

Answer 21

They are pores in the epidermis which allow gas exchange

Question 22

Explain the structure of stomata and how this helps their function

Answer 22

Stomata can change shape by taking in or losing water
The walls of the God cells are thickened on the inside
This means that when they swell by water, they bulge outwards meaning the stoma opens on the inside
When the Gaurd cells lose water, they shrink and the stomach closes

Question 23

What controls stomata opening and closing?

Answer 23

The level of CO2 in the airspace controls the opening and closing stomata by affecting the amount of water guard cells taken in by osmosis

Question 24

Explain how in daylight s stomata change shape

Answer 24

In daylight, CO2 levels are low as it is being used by the leaves for photosynthesis
This means the God tells them taken water by osmosis and become turgid

The store opens

Question 25

Explain in the night, how the stoma change shape

Answer 25

The CO2 levels in the airspace are high in the night as it is not being used for photosynthesis
God helps lose water by osmosis and become flaccid

The stoma closes

Question 26

In what ways are minerals absorbed by the roots?

Answer 26

By diffusion or active transport

Question 27

How are minerals taken in and transported by plants?

Answer 27

They are absorbed by root epidermal cells by diffusion and active transport and then transported to all parts of the plant as they dissolve in the water in the xylem vessel

Question 28

How is CO2 taken in and transported by plants?

Answer 28

Plants get CO2 from respiration in their own cells and also from the atmosphere

CO2 from the atmosphere diffuses through open stomata in plants
It is then transported around the plant by diffusion as a diffuses between the air spaces between cells

Question 29

What are the two main products of photosynthesis?

Answer 29

Glucose and oxygen

Question 30

How is oxygen transported around plants?

Answer 30

Oxygen diffuses into the air spaces in the leaves by the stomata in the leaf and then into the atmosphere

Oxygen is produced in photosynthesis

Question 31

How is glucose transported around a plant?

Answer 31

Glucose is the main carbohydrate produce in photosynthesis. It can be used in respiration, stored starch, or made into sucrose or cellulose

Starch is stored in the spongy mass of cells
The glucose that is converted to sucrose is carried to other part of the plants through the phloem as sap where it is used for growth and respiration

Question 32

What are the ways in which food is stored in plants?

Answer 32

Modified root
Modified stems
Modified leaves

Question 33

Name A food storage polysaccharide found in plants

Answer 33

Starch

Question 34

Name a type of modified stem that function is food storage

Answer 34

Tuber, which is another word for potato

Question 35

Name a plant in which the leaves are modified for food storage

Answer 35

And onion

Question 36

Name a plant in which the stem is modified for food storage

Answer 36

Potato plants grow tubers

Question 37

Name a plant in which the roots are modified to store food

Answer 37

A carrot

Question 38

Explain the upward movement of water

Answer 38

Water enters roots by osmosis
It enters the xylem, causing the buildup of pressure as more water is pushed in
Water molecules stick together due to hydrogen bonding by cohesion
Through adhesion water molecules stick to the walls of the xylem vessels
Water is lost by transpiration in the leaf
Meaning water is pulled upwards as the molecules are stuck together towards the leaf to replace the water that is lost creating a column of water

Question 39

Name the pores found in bark that allow gas exchange

Answer 39

Lenticels

Question 40

Required by plants for photosynthesis

Answer 40

Magnesium

Question 41

Name one of the source of carbon dioxide than the atmosphere in plants

Answer 41

Respiration of the plant cells

Question 42

How are modified roots storing food?

Answer 42

The tap route becomes swollen and flashy with stored fruit that was produced by the leaves during photosynthesis

The food can be used to provide energy for the plant or for humans to harvest

Question 43

Explain modified stems

Answer 43

In some plants, the stems tips swell up to store food and for tubers potato plants have an underground stem system and the tips become swollen with stored starch

Question 44

Explain modified leaves

Answer 44

These are swollen flashy leaves that are modified to store food. They usually have an underground stem system that is reduced insides.

Question 45

How does carbon dioxide exchange in leaves?

Answer 45

Carbon dioxide diffuse from the atmosphere into the stomata on the underside of the leaf
The air spaces increased the surface area for CO2 to the fuse more readily into the mesophyll

Question 46

What Diffusers into the lenticels and what diffuses out

Answer 46

Ingo oxygen and outgoes carbon dioxide and water