Plant tissues & organs - AQA Biology GCSE

What is a tissue in plants?

A group of similar cells working together to perform a particular function.

What is an organ in plants?

A group of different tissues working together to perform a particular function.

Name the 3 main plant organs and their functions.

1. Leaves – carry out photosynthesis

2. Stem – supports leaves, flowers and fruit

3. Roots – absorb water and minerals, and anchor the plant.

List at least 3 other plant organs.

Flowers, fruit, and seeds.

What are the tissues in a leaf?

Upper epidermis, palisade mesophyll, spongy mesophyll, xylem, phloem, lower epidermis.

What is the function of the waxy cuticle and upper epidermis?

Waxy cuticle is waterproof and transparent, protecting against water loss and pathogens and allowing light to reach photosynthesizing cells.

What adaptations do palisade mesophyll cells have for photosynthesis?

Many chloroplasts for more light absorption. They’re closely packed together to maximize light absorption and are located near the top of the leaf, near to the light source.

How does spongy mesophyll facilitate photosynthesis?

It has many air spaces and a large surface area, allowing faster diffusion of gases (carbon dioxide and oxygen).

What is the role of the vascular bundle in a leaf?

Xylem transports water and minerals from the roots, while phloem transports products of photosynthesis (eg. sucrose and amino acids) to the rest of the plant.

What functions do stomata serve?

Allow gas exchange: carbon dioxide enters for photosynthesis, and oxygen (and water vapour) exits. Closed at night to reduce water loss.

What do guard cells do?

Change shape to control the opening and closing of stomata, affecting water loss.

Where is meristem tissue found?

At the growing tips of roots and shoots.

What is the function of meristem tissue?

It’s made up of plant cells that divide and differentiate into all cell types needed for plant growth and repair.