TEST OF PRACTICAL KNOWLEDGE QUESTION
. Study specimens A and B and answer questions 1(a) to 1(c).
(a)(i) Name the habitat of each of specimens A and B. (ii) Name the adult stages into which each of specimens A and B would develop.
(iii) Name the phylum and class common to the adult stages into which each of specimens A and B.
(b) State three observable features of biological significance in: (i) specimen A (ii) specimens B.
(c)(i) State four observable structural differences between specimens A and B.
(ii) State three observable similarities between specimens A and B.
2. Study specimens C, D and E and answer questions 2(a) to 2(c).
(a)(i) Name the organism from which each of specimens C, D and E are obtained.
(ii) State the function common to specimens C, D and E.
(iii) State three observable features which adapts specimen C to its function.
(b)(i) State three observable structural similarities between specimens C and D.
(ii) State three observable structural differences between specimens C and D.
(c) Make a drawing 6cm - 8cm long of specimen C and label fully.
(3) Study specimens K and L and answer questions 3(a) to 3(c).
(a)(i) Name the floral parts of specimen K. (ii) Indicate the number of the floral parts in each whorl of specimen K.
(b)(i) Name the sex of specimen K. (ii) Give one reason for your answer in 3(b)(i).
(c)(i) What is the symmetry of specimen K?. (ii) Give one reason for your answer in 3(c)(i).
(d) Name one pollinating agent of each of specimens K and L.
(e) State four observable structural differences between specimens K and L.
(f) Make a drawing 8cm - 10cm long of specimen K and label fully.
Specimens A to L are not shown. From the wording the specimens are: A and B, two immature (larval) stages that develop into adult insects; C, D and E, three feathers taken from a bird; and K and L, two flowers. The answers below follow that standard reading and set out the reasoning expected; the exact specimens must be read from the real practical.
1(a)(i) Habitat of A and B: A (e.g. mosquito larva) lives in stagnant fresh water; B (e.g. butterfly caterpillar) lives on the leaves of green plants.
1(a)(ii) Adult stages: A develops into an adult mosquito; B develops into an adult butterfly (both are adult insects).
1(a)(iii) Common phylum and class of the adults: Phylum Arthropoda, Class Insecta.
1(b) Three observable features of biological significance
- Specimen A (aquatic larva): breathing siphon/tube for taking in air, and a body suited to wriggling in water.
- Specimen B (caterpillar): strong biting mouthparts and clasping legs for feeding on and gripping leaves.
1(c)(i) Four structural differences (A vs B): A is aquatic with a breathing siphon, B is terrestrial without one; A has no true legs on the abdomen, B has prolegs; A wriggles, B crawls; A has a small head, B a distinct head with strong jaws.
1(c)(ii) Three similarities: both are larval stages of insects; both have a segmented body; both moult as they grow and later pupate.
2(a)(i) Organism yielding C, D and E: a bird.
2(a)(ii) Common function: the feathers provide covering; specifically insulation and flight.
2(a)(iii) Three features adapting C (flight feather) to its function: broad, flat vane for pushing air; interlocking barbs and barbules held by hooks giving an unbroken surface; a light but strong central shaft (rachis).
2(b)(i) Three similarities (C and D): both have a central shaft; both bear barbs; both are made of keratin.
2(b)(ii) Three differences (C flight feather vs D down feather): C has a stiff shaft, D a weak one; C has interlocking barbs, D has loose free barbs; C is used for flight, D for insulation.
2(c) Drawing 6 to 8 cm long of specimen C labelling: shaft (rachis), quill (calamus), vane, barbs.
3(a)(i) Floral parts of K: sepals (calyx), petals (corolla), stamens (androecium) and carpels/pistil (gynoecium).
3(a)(ii) Number in each whorl: to be counted from the actual specimen K.
3(b)(i) Sex of K: bisexual (hermaphrodite) if it carries both stamens and carpels.
3(b)(ii) Reason: it has both the male part (stamens) and the female part (carpels) in the same flower.
3(c)(i) Symmetry of K: actinomorphic (radial) if it can be cut into equal halves in more than one plane.
3(c)(ii) Reason: the floral parts are arranged regularly around the centre so more than one plane divides it into equal halves.
3(d) Pollinating agent: K (large, coloured, scented) insect-pollinated; L (small, dull, feathery stigma) wind-pollinated.
3(e) Four differences (K vs L): K has large coloured petals, L small or no petals; K is scented, L is not; K has enclosed anthers, L has exposed anthers; K has a compact stigma, L a large feathery stigma.
3(f) Drawing 8 to 10 cm long of specimen K labelling: sepal, petal, stamen (anther and filament), stigma, style, ovary.
Specimens A to L are not shown. From the wording the specimens are: A and B, two immature (larval) stages that develop into adult insects; C, D and E, three feathers taken from a bird; and K and L, two flowers. The answers below follow that standard reading and set out the reasoning expected; the exact specimens must be read from the real practical.
1(a)(i) Habitat of A and B: A (e.g. mosquito larva) lives in stagnant fresh water; B (e.g. butterfly caterpillar) lives on the leaves of green plants.
1(a)(ii) Adult stages: A develops into an adult mosquito; B develops into an adult butterfly (both are adult insects).
1(a)(iii) Common phylum and class of the adults: Phylum Arthropoda, Class Insecta.
1(b) Three observable features of biological significance
- Specimen A (aquatic larva): breathing siphon/tube for taking in air, and a body suited to wriggling in water.
- Specimen B (caterpillar): strong biting mouthparts and clasping legs for feeding on and gripping leaves.
1(c)(i) Four structural differences (A vs B): A is aquatic with a breathing siphon, B is terrestrial without one; A has no true legs on the abdomen, B has prolegs; A wriggles, B crawls; A has a small head, B a distinct head with strong jaws.
1(c)(ii) Three similarities: both are larval stages of insects; both have a segmented body; both moult as they grow and later pupate.
2(a)(i) Organism yielding C, D and E: a bird.
2(a)(ii) Common function: the feathers provide covering; specifically insulation and flight.
2(a)(iii) Three features adapting C (flight feather) to its function: broad, flat vane for pushing air; interlocking barbs and barbules held by hooks giving an unbroken surface; a light but strong central shaft (rachis).
2(b)(i) Three similarities (C and D): both have a central shaft; both bear barbs; both are made of keratin.
2(b)(ii) Three differences (C flight feather vs D down feather): C has a stiff shaft, D a weak one; C has interlocking barbs, D has loose free barbs; C is used for flight, D for insulation.
2(c) Drawing 6 to 8 cm long of specimen C labelling: shaft (rachis), quill (calamus), vane, barbs.
3(a)(i) Floral parts of K: sepals (calyx), petals (corolla), stamens (androecium) and carpels/pistil (gynoecium).
3(a)(ii) Number in each whorl: to be counted from the actual specimen K.
3(b)(i) Sex of K: bisexual (hermaphrodite) if it carries both stamens and carpels.
3(b)(ii) Reason: it has both the male part (stamens) and the female part (carpels) in the same flower.
3(c)(i) Symmetry of K: actinomorphic (radial) if it can be cut into equal halves in more than one plane.
3(c)(ii) Reason: the floral parts are arranged regularly around the centre so more than one plane divides it into equal halves.
3(d) Pollinating agent: K (large, coloured, scented) insect-pollinated; L (small, dull, feathery stigma) wind-pollinated.
3(e) Four differences (K vs L): K has large coloured petals, L small or no petals; K is scented, L is not; K has enclosed anthers, L has exposed anthers; K has a compact stigma, L a large feathery stigma.
3(f) Drawing 8 to 10 cm long of specimen K labelling: sepal, petal, stamen (anther and filament), stigma, style, ovary.
