Biology Paper 1 - Plant Tissues, Organs And Organ Systems

Question 1

Epidermal Tissue

Answer 1

Cover the surface of plant tissue and protect them.

Often secretes a waxy substance that waterproofs the surface of the leaf.

Question 2

Palisade Mesophyll

Answer 2

Contains lots of chloroplasts for photosynthesis.

Question 3

Spongy Mesophyll

Answer 3

Tissue contains some chloroplasts for photosynthesis but also has big air spaces and a large SA to make diffusion of gases easier.

Question 4

Xylem

Answer 4

Carry water and mineral ions from roots of plant to leaves.

Question 5

Phloem

Answer 5

Carries dissolved food from leaves to rest of plant.

Question 6

Meristem Tissue

Answer 6

Made of rapidly dividing plant cells that grow and differentiate into all other cell types needed.

Question 7

Stomata And Guard Cells

Answer 7

Stomata : Allow gases to move in and out of leaves, like CO2

Guard Cells : Control the opening and closing of the Stomata.

Question 8

Translocation

Answer 8

The movement of dissolved sugars from the leaves to the rest of the plant
Carried out by Phloem

Question 9

Transpiration

Answer 9

When the stomata are open, plants lose water vapour through them. It passes out of the leaf through the stomata by diffusion.
Loss of water vapour = transpiration.

Question 10

Transpiration Stream

Answer 10

As water evaporates from the leaves via the opening of Stomata, more water is pulled up from the Xylem to replace the loss of water. This constant movement of water is called the transpiration stream.

Question 11

Composition Of Xylem

Answer 11

It is composed of hollow tubes strengthened by lignin adapted for the transport of water in the transpiration stream.

Question 12

Composition Of Phloem

Answer 12

Phloem is composed of tubes of elongated cells. Cell sap can move from one phloem cell to the next through pores in the end walls.