Leaves of Dicotyledonous Plants

Question 1

What does a waxy cuticle do

Answer 1

The cells are quite transparent and permit most of the light that strikes them to pass through to the underlying cells. The upper surface is covered with a waxy, waterproof cuticle, which serves to reduce water loss from the leaf

Question 2

what does the upper epidermis do

Answer 2

This is a single layer of cells containing few or no chloroplasts. The cells are quite transparent and permit most of the light that strikes them to pass through to the underlying cells

Question 3

Palisade mesophyll layer what does it do

Answer 3

The palisade mesophyll layer is where most of the photosynthesis occurs in the leaf. The palisade cells contain a lot of chloroplasts to help them perform this photosynthesis. The palisade cells are closely packed together to maximize light absorption.

Question 4

Spongy mesophyll layer

Answer 4

The spongy mesophyll cells are covered by a thin layer of water. Gases dissolve in this water as they move into and out of the cells. When the plant is photosynthesising during the day, these features allow carbon dioxide to diffuse into the spongy mesophyll cells, and oxygen to diffuse out of them.

extensive network of air spaces

Question 5

Stomata

Answer 5

Stomata play a critical role in gas exchange as they allow carbon dioxide to enter the plant and oxygen to be released. The opening and closing of stomata are regulated by the plant to maintain a balance between the uptake of carbon dioxide and the release of oxygen.

Question 6

guard cells what happens when the plant is full with water and lacks it

Answer 6

These are cells found outside the stomata. There are two of them shaped rather like long balloons. They exist in the plants to control gas exchange and water loss. When the plant takes in lots of water via osmosis, the guard cells become turgid (plump) and this results in them bending slightly and the stomata opening allowing lots of gas exchange and loss of water via transpiration.

When the plants lack water, the guard cells become flaccid (floppy) and this shuts the stomata, preventing further water loss.

Question 7

lower epidermis

Answer 7

The lower epidermis of a leaf contains stomata and guard cells that allow carbon dioxide to enter the leaf, and oxygen and excess water to exit the leaf.

Question 8

order bottom to up the structures

Answer 8

guard cells , stomata, lower epidermis, spongy mesophyll layer, palisade mesophyll, upper epidermis cuticle