Plant Cell Organisation Flashcards
1
Q
What are plants made of?
A
Organs like stems, roots and leaves.
2
Q
Plant organs work together to make_?
A
Organ systems.
3
Q
What can organ systems perform?
A
Various tasks that a plant needs to carry out to survive and grow - for example, transporting substances around the plant.
4
Q
Examples of plant tissues .
A
- Epidermal tissues - covers the whole plant.
- Palisade mesophyll tissue - part of leaf where photosynthesis happens.
- Spongy mesophyll tissue - part of leaf, contains big air spaces to allow gases to diffuse in and out of cells.
- Xylem and phloem - transport things like water, mineral ions and food around the plant (through roots, stems and leaves).
- Meristem tissue - found at the growing tips of shoots and roots and is able to differentiate into lots of different types of plant cell, allowing the plant to grow.
5
Q
What tissues do leaves contain?
A
Epidermal, mesophyll, xylem and phloem tissues.
6
Q
How are the structures of the tissues that make up the leaf related to their function?
A
- The epidermal tissues are covered with a waxy cuticle, which helps to reduce water loss by evaporation.
- The upper epidermis is transparent so that light can pass through it to the palisade layer.
- The palisade layer has lots of chloroplasts. This means that they’re near the top of the leaf where they can get the most light.
- The xylem and phloem form a network of vascular bundles, which deliver water and other nutrients to the entire leaf and take away the glucose produced by photosynthesis. They also help support the structure.
- The tissues of leaves are also adapted for efficient gas exchange. E.g. the lower epidermis is full of little holes called stomata, which let carbon dioxide diffuse directly into the leaf. The opening and closing of stomata are controlled by guard cells in response to environmental conditions. The air spaces in the spongy mesophyll tissue increase the rate of diffusion of gases.
