OCR transpiration

What is transpiration in plants?

• Absorption of carbon dioxide through stomata
• Release of water vapour into the atmosphere through stomata
• Movement of water down the stem
• Uptake of minerals through roots

What is the main purpose of the transpiration stream in plants?

• Cooling the plant
• Providing minerals to the roots
• Facilitating gas exchange
• Supplying water for photosynthesis and growth

What process is involved in transpiration that moves water from the xylem to mesophyll cells?

• Osmosis
• Diffusion
• Active transport
• Translocation

How can the rate of transpiration be measured?

• Using a potometer
• Counting the number of leaves
• Measuring the leaf surface area
• Observing stomata under a microscope

What factors affect the rate of transpiration?

• Number of leaves, temperature and humidity
• Leaf colour, soil pH and air pressure
• Stomata size, root length and water availability
• Light intensity, air movement and water temperature

How do xerophytes reduce water loss?

• By increasing number of stomata
• Decreasing the size of leaves
• By opening stomata during dry conditions
• By thickening the waxy cuticle and rolling leaves

What is a characteristic adaptation of hydrophytes to their aquatic environment?

• Thick waxy cuticle
• Small surface area for light absorption
• Constantly open stomata
• Densly packed mesophyll cells

What do air sacs in hydrophytes help with?

• Gas exchange
• Water absorption
• Root anchoring
• Buoyancy

: Which type of plant has a thin or absent waxy cuticle?

• Xerophytes
• Mesophytes
• Hydrophytes
• Epiphytes

What is the primary function of wide, flat leaves in hydrophytes?

• Water retention
• Nutrient absorption
• Gas exchange
• Sunlight absorption