organising plants b6

Why is a leaf an organ

There are many tissues inside the leaf that work together to perform photosynthesis

How is the upper epidermis adapted for its function

• single layer of transparent cells allow light to pass through

• Cells secrete a waxy substance that makes leaves waterproof

How is palisade mesophyll adapted for its function

• tightly packed cells with lots of chloroplasts to absorb as much light as possible for photosynthesis

How is the spongy mesophyll adapted for its function

• air spaces increase the surface area and allow gases to diffuse quickly

What is the function of guard cells

Control the opening and closing of the stomata

What is the function of the xylem

Transports water and mineral ions from the roots to the rest of the plant

What is the purpose of translocation

Transports dissolved sugars from the leaves to the rest of the plant

What is the purpose of transpiration

• Provides water to keep cells turgid

• Provides water to cells for photosynthesis

• Transports mineral ions to leaves

Name four factors that affect the rate of transpiration

• temperature

• light intensity

• Humidity

• Wind speed

What is the function of the stomata

Allow diffusion of gases into and out of the plant

What affect does temperature have on the rate of transpiration

Higher temperature increases the rate of transpiration

Why does increased light intensity increase the rate of transpiration

Stomata open wider to let more carbon dioxide into the leaf for photosynthesis

Where are most stomata found

Underside of leaves

What is the advantage of having a high number of stomata at this location

Reduces the amount of water loss due to evaporation