structures of a leaf (at microscopic level) and state their main function

Question 1

Upper epidermis

Answer 1

• This layer of cells on the top surface of leaves
• provides protection
• often transparent to allow light to pass through for photosynthesis.

Question 2

Palisade mesophyll cells

Answer 2

• These cells are densely packed with chloroplasts
• are the main site for photosynthesis, converting light energy into chemical energy.

Question 3

Spongy mesophyll cells

Answer 3

• Cells with large air spaces between them
• Facilitate gas exchange (CO₂ and O₂)
• Perform some photosynthesis

Question 4

Lower epidermis

Answer 4

Protects the lower surface of the leaf and often contains stomata, which allow for gas exchange.

Question 5

Stoma (stomata pl.)

Answer 5

Pores on the leaf that control gas exchange

Question 6

Guard cells

Answer 6

Specialized cells that surround each stoma, controlling its opening and closing, regulating water loss, and gas exchange.

Question 7

Vascular bundle

Answer 7

Consists of xylem and phloem tissues; transports water, nutrients, and food throughout the plant.

Question 8

Xylem

Answer 8

Part of the vascular bundle; transports water and minerals from the roots to the leaves.

Question 9

Phloem

Answer 9

Part of the vascular bundle; transports the products of photosynthesis (sugars) from the leaves to other parts of the plant.

Question 10

Cuticle

Answer 10

• Waxy, waterproof layer covering the epidermis
• Reduces water loss
• Protects against environmental stress

Question 11

Air space

Answer 11

Helps gas exchange within the leaf

Question 12

Bundle sheath

Answer 12

compact cells surrounding a vascular bundle