Study specimens A, B and C carefully and use them to answer questions (a) to (d). (a) State the habitats specimens A, Band C. (b) State (i) two observable f...

Answer Details

(a) Habitats of specimens A, B and C

(b)(i) Two observable features and (ii) how each adapts the specimen to its habitat

Specimen A (Water lettuce)

• Broad, spongy leaves borne in a rosette – keep the plant buoyant and expose the maximum surface to sunlight for photosynthesis.
• Numerous fine adventitious roots hanging in the water – absorb water and mineral salts and aid flotation; fine hairs on the leaves also prevent water from blocking the stomata.

Specimen B (Cactus)

• Leaves modified into spines – greatly reduce water loss by transpiration and deter herbivores.
• Succulent green stem with a thick waxy cuticle – stores water and checks water loss while still carrying out photosynthesis.

Specimen C (Waterleaf / Talinum sp.)

• Well-developed swollen taproot – anchors the plant, absorbs water and mineral salts, and stores food.
• Erect branched stem bearing numerous green leaves – holds the leaves up to receive maximum sunlight for photosynthesis.

(c) Three observable differences between specimens A and C

(d) Drawing of specimen C (Waterleaf / Talinum sp.)

The drawing below, 8–10 cm long, shows specimen C in correct proportion with all parts fully labelled using ruled label lines that do not cross.