. 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 eac...
. 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.
Question 1 - Specimens A and B (immature insect stages: A a mosquito larva, B a caterpillar)
(a)(i) Habitat. A lives in stagnant fresh water (ponds, pools, gutters, water tanks); B lives on the leaves of green plants on land.
(a)(ii) Adult stages. A develops into an adult mosquito; B develops into an adult butterfly (or moth).
(a)(iii) Common phylum and class of the adults. Phylum Arthropoda; Class Insecta.
(b) Three observable features of biological significance
Specimen A: a breathing siphon at the tail for taking in air at the water surface; a segmented, comma-shaped body that allows wriggling in water; tufts of bristles/hairs that aid movement and filter feeding.
Specimen B: strong biting-and-chewing mouthparts for feeding on leaves; three pairs of jointed true legs plus fleshy prolegs for gripping the plant; a soft, distinctly segmented body that permits growth by moulting.
(c)(i) Four structural differences (A and B)
Specimen A
Specimen B
Has a breathing siphon
Has no siphon
Has no true jointed legs on the body
Has three pairs of true legs and prolegs
Head small and poorly developed
Head distinct with strong jaws
Moves by wriggling in water
Moves by crawling on leaves
(c)(ii) Three similarities. Both are larval (immature) stages of insects; both have a clearly segmented body; both grow by moulting and later pupate before becoming adults.
Question 2 - Specimens C, D and E (three feathers of a bird: C a flight feather, D a down feather, E a body/contour feather)
(a)(i) Organism. All three specimens are obtained from a bird.
(a)(ii) Common function. They form the body covering (plumage) of the bird, giving insulation, protection and streamlining.
(a)(iii) Three features adapting C (flight feather) to its function. A broad, flat vane that pushes against the air during flight; barbs held firmly together by interlocking hooked barbules, giving a continuous air-tight surface; a light but strong central shaft (rachis) that is firm yet flexible.
(b)(i) Three similarities between C and D. Each has a central shaft; each bears barbs branching from the shaft; both are made of the horny protein keratin.
(b)(ii) Three differences between C and D
Specimen C (flight feather)
Specimen D (down feather)
Shaft stiff and firm
Shaft slender and weak
Barbs interlocked by hooked barbules (firm vane)
Barbs free and loose (fluffy)
Used mainly for flight
Used mainly for insulation
(c) Drawing of specimen C (6 cm to 8 cm long), fully labelled:
Labelled drawing of specimen C, a flight (contour) feather, showing the tip, vane, barbs, rachis (shaft) and calamus (quill).
Question 3 - Specimens K and L (K an insect-pollinated flower, L a wind-pollinated grass flower)
(a)(i) Floral parts of K. The sepals (calyx), the petals (corolla), the stamens (androecium: each an anther on a filament) and the carpel/pistil (gynoecium: stigma, style and ovary).
(a)(ii) Number in each whorl. Calyx: five sepals; corolla: five petals; androecium: ten stamens; gynoecium: one pistil (a single carpel).
(b)(i) Sex of K. It is a bisexual (hermaphrodite) flower.
(b)(ii) Reason. It bears both the male parts (stamens) and the female part (carpel/pistil) within the same flower.
(c)(i) Symmetry of K. It is actinomorphic (regular / radially symmetrical).
(c)(ii) Reason. It can be divided into two equal halves along more than one vertical plane passing through the centre.
(d) One pollinating agent of each. Specimen K: an insect (for example a bee or butterfly). Specimen L: wind.
(e) Four structural differences between K and L
Specimen K (insect-pollinated)
Specimen L (wind-pollinated)
Petals large, brightly coloured and conspicuous
Petals absent or small, green and inconspicuous
Stamens enclosed within the flower
Stamens long and hang outside the flower
Stigma small, sticky and inside the flower
Stigma large, feathery and hangs out
Nectar and scent present
Nectar and scent absent
(f) Drawing of specimen K (8 cm to 10 cm long), fully labelled:
Labelled longitudinal section of specimen K, a bisexual flower, showing sepal, petal, stamen (filament and anther) and carpel (ovary with ovules, style and stigma).
Question 1 - Specimens A and B (immature insect stages: A a mosquito larva, B a caterpillar)
(a)(i) Habitat. A lives in stagnant fresh water (ponds, pools, gutters, water tanks); B lives on the leaves of green plants on land.
(a)(ii) Adult stages. A develops into an adult mosquito; B develops into an adult butterfly (or moth).
(a)(iii) Common phylum and class of the adults. Phylum Arthropoda; Class Insecta.
(b) Three observable features of biological significance
Specimen A: a breathing siphon at the tail for taking in air at the water surface; a segmented, comma-shaped body that allows wriggling in water; tufts of bristles/hairs that aid movement and filter feeding.
Specimen B: strong biting-and-chewing mouthparts for feeding on leaves; three pairs of jointed true legs plus fleshy prolegs for gripping the plant; a soft, distinctly segmented body that permits growth by moulting.
(c)(i) Four structural differences (A and B)
Specimen A
Specimen B
Has a breathing siphon
Has no siphon
Has no true jointed legs on the body
Has three pairs of true legs and prolegs
Head small and poorly developed
Head distinct with strong jaws
Moves by wriggling in water
Moves by crawling on leaves
(c)(ii) Three similarities. Both are larval (immature) stages of insects; both have a clearly segmented body; both grow by moulting and later pupate before becoming adults.
Question 2 - Specimens C, D and E (three feathers of a bird: C a flight feather, D a down feather, E a body/contour feather)
(a)(i) Organism. All three specimens are obtained from a bird.
(a)(ii) Common function. They form the body covering (plumage) of the bird, giving insulation, protection and streamlining.
(a)(iii) Three features adapting C (flight feather) to its function. A broad, flat vane that pushes against the air during flight; barbs held firmly together by interlocking hooked barbules, giving a continuous air-tight surface; a light but strong central shaft (rachis) that is firm yet flexible.
(b)(i) Three similarities between C and D. Each has a central shaft; each bears barbs branching from the shaft; both are made of the horny protein keratin.
(b)(ii) Three differences between C and D
Specimen C (flight feather)
Specimen D (down feather)
Shaft stiff and firm
Shaft slender and weak
Barbs interlocked by hooked barbules (firm vane)
Barbs free and loose (fluffy)
Used mainly for flight
Used mainly for insulation
(c) Drawing of specimen C (6 cm to 8 cm long), fully labelled:
Labelled drawing of specimen C, a flight (contour) feather, showing the tip, vane, barbs, rachis (shaft) and calamus (quill).
Question 3 - Specimens K and L (K an insect-pollinated flower, L a wind-pollinated grass flower)
(a)(i) Floral parts of K. The sepals (calyx), the petals (corolla), the stamens (androecium: each an anther on a filament) and the carpel/pistil (gynoecium: stigma, style and ovary).
(a)(ii) Number in each whorl. Calyx: five sepals; corolla: five petals; androecium: ten stamens; gynoecium: one pistil (a single carpel).
(b)(i) Sex of K. It is a bisexual (hermaphrodite) flower.
(b)(ii) Reason. It bears both the male parts (stamens) and the female part (carpel/pistil) within the same flower.
(c)(i) Symmetry of K. It is actinomorphic (regular / radially symmetrical).
(c)(ii) Reason. It can be divided into two equal halves along more than one vertical plane passing through the centre.
(d) One pollinating agent of each. Specimen K: an insect (for example a bee or butterfly). Specimen L: wind.
(e) Four structural differences between K and L
Specimen K (insect-pollinated)
Specimen L (wind-pollinated)
Petals large, brightly coloured and conspicuous
Petals absent or small, green and inconspicuous
Stamens enclosed within the flower
Stamens long and hang outside the flower
Stigma small, sticky and inside the flower
Stigma large, feathery and hangs out
Nectar and scent present
Nectar and scent absent
(f) Drawing of specimen K (8 cm to 10 cm long), fully labelled:
Labelled longitudinal section of specimen K, a bisexual flower, showing sepal, petal, stamen (filament and anther) and carpel (ovary with ovules, style and stigma).
