Nutrition and Transport in Plants

Stomata are important in a leaf because they allow for:

• Store starch

• Water absorption only

• gas exchange in photosynthesis and transpiration
• Transport of food

What is the main function of phloem tissue?

• Translocation of manufactured food (sucrose and amino acids)

• Transport of water and mineral salts

• To facilitate gas exchange
• To provide structural support

Which feature of a root hair cell increases its ability to absorb water?

• Thick cell wall

• Presence of chloroplasts

• Large central vacuole

• Long and narrow extension

What is the role of chlorophyll in photosynthesis?

• Absorbs carbon dioxide for photosynthesis

• Conducts water and mineral salts up the plant

• Absorbs light energy and converts it into chemical energy

• Breaks down glucose to release energy

​ ​photosynthesis: (a)   + water -> ​ ​ (b)   + (c)  

• carbon dioxide
• oxygen
• glucose

How does carbon dioxide enter the mesophyll cells of a leaf?

• Through xylem vessels

• By osmosis through cell membranes

• Through stomata and diffuses into cells

• Through phloem tissues

Transpiration is best defined as:

• Movement of water through phloem

• Evaporation of water from leaf surface

• Loss of water vapour from stomata

• Uptake of water from roots

Which force helps to pull water up the stem during transpiration?

• Gravity

• Transpiration pull

• Diffusion gradient

Wilting occurs when:

• The roots take up too much water

• Light intensity is very low

• Water loss exceeds water uptake

• The plant produces excess glucose

• This layer contains the most chloroplasts and is the main site of photosynthesis in a leaf