IB PLANT BIOLOGY HL

Front

What factor decreases the rate of transpiration in plants?

Back

Humidity increases the moisture in the air, reducing the water vapor gradient between the inside of the leaf and the outside, thus decreasing transpiration.

Front

What is the main site of photosynthesis in a leaf?

Back

The palisade mesophyll cells are the main site of photosynthesis due to their high chloroplast density.

Front

What is the structure of xylem vessels?

Back

Xylem vessels have no end walls, contain lignin for support, and have pits in their outer cell walls for water movement.

Front

Where are cells usually taken from in micropropagation?

Back

Cells are usually taken from the shoot apex, which is the growing tip of the plant.

Front

Which organelle in a plant cell has a double membrane?

Back

Chloroplasts have a double membrane, which is essential for their function in photosynthesis.

Front

What is transpiration?

Back

Transpiration is the process of water vapor loss from plant leaves through stomata.

Front

What role do stomata play in plants?

Back

Stomata are small openings on the leaf surface that regulate gas exchange and transpiration.

Front

What is the function of lignin in xylem?

Back

Lignin provides structural support and rigidity to xylem vessels, allowing them to withstand the pressure of water transport.

Front

What is the difference between xylem and phloem?

Back

Xylem transports water and minerals from roots to leaves, while phloem transports sugars and nutrients throughout the plant.

Front

What is the significance of the spongy mesophyll in leaves?

Back

The spongy mesophyll facilitates gas exchange and contains air spaces that allow for the diffusion of gases.