Plant Tissue

Structure of the Plant

Part of the Leaf	How is it adapted for photosynthesis and gas exchange?
Broad leaves	Increase surface area by being broad. Underneath, it is porous with lots of air spaces between the outer layers of cells.
Stomata in the lower epidermis	Helps with gas exchange - the stomata can open and close so that it controls which gases and water can exit or enter.
Thin leaf shape	Short distance for the gas exchange to take place
Xylem and Phloem	Network that allow substances to be transported to the right places of the plant so that growth can take place
Cuticle	Waxy layer to prevent too much water to be lost during evaporation.
Transparent epidermis	Allow light to get through to the chlorophyll so that light can be absorbed for photosynthesis
Spongy Mesophyll	Irregular cell shapes with large spaces so that gas exchange can take place between stomata and photosynthesizing cells
Palisade Mesophyll	Where lots of chloroplasts can be found, so that photosynthesis can take place. Irregular shapes to allow gases to pass through. This is located near the top so that it can absorb more light for photosynthesis to take place.
Meristems	Stem cells can also be found in specific regions of plants are found in the tip of the roots and shoots. Meristems exist in plants as it ensures that plants have the capacity to grow taller and wider throughout its life.

Root Hair Cells

Plants are able to absorb water through osmosis, and absorb mineral ions through active transport. Root hair cells are adapted so that they can carry out these functions. Root hair cells are long and thin, which gives them a large surface area in order to increase the rate of absorption. They contain mitochondria which is needed for active transport as it moves the minerals against the concentration gradient. Mitochondria releases energy from the glucose during respiration so that it can provide the energy that is required for active transport.

Xylem

The xylem is a plant tissue that is vital for the plant as it transports water and minerals from the roots to the plant’s stem and leaves. Part of the Xylem is made of dead cells. They do not have a end wall as the xylem is a continuous hollow tube. Lignin can be found in their walls as it strengthens the plant. The transportation of water and minerals does not require any energy.

Phloem

The phloem is also an important plant tissue as it moves food substances (sucrose) that were produced through photosynthesis towards growing parts of the plant, storage organs (bulbs and tubers) and developing seeds. The substances that transport throughout the phloem will travel both up and down the stem as there are so many different parts of the plant that require the food.

What does the phloem transport?

Your answer should include: Food / Substances

Through which process do root hair cells absorb water from the soil?

Osmosis