2(e) NUTRITION · RECALL

2.21 Leaf structure and photosynthesis

18 recall questions. Answer from memory, reveal the answer, then rate yourself. Ratings stay on this device.

Open the lesson · Exam questions for 2.21

Ratings are saved in this browser on this device, under a KS4 key kept separate from International A Level recall. Written answers are temporary and cleared when you leave the page. Use Reset to clear the ratings on this device.

012.21Pearson Edexcel focus

List the leaf layers from top to bottom.

Reveal answer

Waxy cuticle, upper epidermis, palisade mesophyll, spongy mesophyll (with air spaces), lower epidermis with stomata and guard cells; veins contain xylem and phloem.

Key words: palisade · spongy · stomata

022.21Lesson

What is meant by the term lamina?

Reveal answer

The broad, flat blade of a leaf.

Key words: lamina

032.21Lesson

What is meant by the term palisade mesophyll?

Reveal answer

Closely packed photosynthetic tissue near the upper leaf surface.

Key words: palisade mesophyll

042.21Lesson

What is meant by the term spongy mesophyll?

Reveal answer

Internal tissue with air spaces supporting gas exchange.

Key words: spongy mesophyll

052.21Lesson

What is meant by the term stoma?

Reveal answer

A pore in the epidermis for gas exchange.

Key words: stoma

062.21Lesson

What is meant by the term guard cell?

Reveal answer

A specialised cell that changes stomatal aperture.

Key words: guard cell

072.21Lesson

What is meant by the term vascular bundle?

Reveal answer

A vein containing xylem and phloem.

Key words: vascular bundle

082.21Lesson

Leaf tissues and functions: for Waxy cuticle, give the feature and the contribution.

Reveal answer

Feature: Transparent, waterproof layer. Contribution: Admits light and reduces evaporation.

Key words: Waxy cuticle

092.21Lesson

Leaf tissues and functions: for Upper epidermis, give the feature and the contribution.

Reveal answer

Feature: Thin and usually lacks chloroplasts. Contribution: Lets light reach palisade cells.

Key words: Upper epidermis

102.21Lesson

Leaf tissues and functions: for Palisade mesophyll, give the feature and the contribution.

Reveal answer

Feature: Many chloroplasts near upper surface. Contribution: Absorbs light for photosynthesis.

Key words: Palisade mesophyll

112.21Lesson

Leaf tissues and functions: for Spongy mesophyll, give the feature and the contribution.

Reveal answer

Feature: Large interconnected air spaces. Contribution: Shortens gas-phase diffusion pathways.

Key words: Spongy mesophyll

122.21Lesson

Leaf tissues and functions: for Xylem, give the feature and the contribution.

Reveal answer

Feature: Lignified water-conducting vessels. Contribution: Supplies water and mineral ions.

Key words: Xylem

132.21Lesson

Leaf tissues and functions: for Phloem, give the feature and the contribution.

Reveal answer

Feature: Living translocation tissue. Contribution: Exports sucrose to sinks.

Key words: Phloem

142.21Lesson

Leaf tissues and functions: for Stoma and guard cells, give the feature and the contribution.

Reveal answer

Feature: Adjustable pore. Contribution: Balances carbon-dioxide uptake against water loss.

Key words: Stoma and guard cells

152.21Lesson

True or false, and why? “Every epidermal cell lacks chloroplasts.”

Reveal answer

False. Most epidermal cells do, but guard cells contain chloroplasts.

162.21Lesson

True or false, and why? “Air spaces store a permanent supply of carbon dioxide.”

Reveal answer

False. They provide pathways through which gases diffuse.

172.21Lesson

True or false, and why? “Stomata stay open whenever there is light.”

Reveal answer

False. Water status and other signals can cause closure even in light.

182.21Lesson

True or false, and why? “Phloem carries glucose directly from the leaf.”

Reveal answer

False. Much transported carbohydrate is converted to sucrose before translocation.

← All recall for 2(e)