3.1.3 transport in plants

Question 1

Why do multicellular plants need a transport system?

Answer 1

• Metabolic demands
• Size
• SA : V

Question 2

How are metabolic demands in plants linked to the need for a transport system?

Answer 2

Oxygen and glucose made during photosynthesis need to be transported to internal and underground cells.
Waste products also need to be removed.
Hormones made in one part need to be moved to areas that they have an effect.
Mineral ions from the roots need to be transported to cells to make the proteins required for enzymes and the structure of the cell.

Question 3

How is size in plants linked to the need for a transport system?

Answer 3

Some plants are extremely big therefore they need to move substances a long distance - up and down from the roots to the leaves and stems.

Question 4

How is surface area : volume linked to the need for transport systems?

Answer 4

Leaves are adapted to have a large SA:V ratio for gaseous exchange. However the whole plant has a fairly small SA:V ratio therefore they cant rely on diffusion alone.

Question 5

Vascular bundles

Answer 5

A vascular system made up of xylem and phloem.

Question 6

Cortex

Answer 6

Unspecialised cell tissue between the epidermis and vascular bundles.

Question 7

Epidermis

Answer 7

The outer layer of cells

Question 8

Phloem

Answer 8

Living tissue that transports organic solutes (sugars and amino acids) from leaves where they are made by photosynthesis. Made from hollow cells connected end to end with to cell wall between them.

Question 9

Xylem

Answer 9

Dead tissue that transports water and minerals from the roots to the leaves. Made from hollow cells connected end to end with to cell wall between them.

Question 10

Endodermis

Answer 10

The inner most layer of the cortex