WAEC SSCE - Biology - 2016 (Practical)
Pregunta 1 Informe
Answer all the questions in this section.
Study specimen S, T, U, V and Wand answer questions 4 (a) to 4(e).
(a) (i) Name the habitats of each of specimens S, U and W.
(ii) Name the class to which each of specimens S, U and W belong.
(b) State: (i) Four observable similarities between specimens S and U. (ii) five observable differences between specimens S and U.
(c)(i) identify the sex of specimen U. (i) State two reasons for the answer in 4 (c)(i).
(d)State four observable features that adapt specimen S to its habitat.
(e) Construct a food chain using at least three of the given specimens.
(a)(i) Habitats
- Specimen S (toad): moist, damp land, under stones and in damp vegetation near freshwater.
- Specimen U (agama lizard): on house walls, in cracks, on trees, in gardens and farmland.
- Specimen W (locust): on vegetation in grassland, farms and on the leaves of plants.
(a)(ii) Class of each
- Specimen S (toad): Amphibia.
- Specimen U (lizard): Reptilia.
- Specimen W (locust): Insecta.
(b)(i) Four similarities between S and U: both have a head bearing eyes, a wide mouth and nostrils; both have four limbs (two pairs); both possess a tympanic membrane (eardrum); and both have a distinct trunk.
(b)(ii) Five differences between S and U
| Specimen S (toad) | Specimen U (lizard) |
|---|---|
| Skin is warty and moist, without scales | Skin is dry and covered with scales |
| Tail absent | Tail present |
| Digits of hind limbs are webbed | Digits are not webbed and end in claws |
| Neck absent, body short and wide | Neck present, body long and narrow |
| Poison gland present; no nuchal crest | No poison gland; nuchal crest present |
(c)(i) Sex of specimen U: male.
(c)(ii) Two reasons: it is brightly coloured with a red head and blue-black trunk with an orange/blue tail; and it bears a prominent nuchal crest and gular fold, which are features of the male agama.
(d) Four features that adapt specimen S (toad) to its habitat: a poison gland in the warty skin for protection against predators; webbed hind digits for swimming in water; long, muscular hind limbs for jumping and hopping on land; and a cryptic (warty, dull) skin colour for camouflage. The moist skin also aids cutaneous respiration.
(e) Food chain (at least three specimens):
Specimen T (grass) → Specimen W (locust) → Specimen S (toad) → Specimen V (hawk).
An alternative valid chain is: Specimen T (grass) → Specimen W (locust) → Specimen U (lizard).
Detalles de la respuesta
(a)(i) Habitats
- Specimen S (toad): moist, damp land, under stones and in damp vegetation near freshwater.
- Specimen U (agama lizard): on house walls, in cracks, on trees, in gardens and farmland.
- Specimen W (locust): on vegetation in grassland, farms and on the leaves of plants.
(a)(ii) Class of each
- Specimen S (toad): Amphibia.
- Specimen U (lizard): Reptilia.
- Specimen W (locust): Insecta.
(b)(i) Four similarities between S and U: both have a head bearing eyes, a wide mouth and nostrils; both have four limbs (two pairs); both possess a tympanic membrane (eardrum); and both have a distinct trunk.
(b)(ii) Five differences between S and U
| Specimen S (toad) | Specimen U (lizard) |
|---|---|
| Skin is warty and moist, without scales | Skin is dry and covered with scales |
| Tail absent | Tail present |
| Digits of hind limbs are webbed | Digits are not webbed and end in claws |
| Neck absent, body short and wide | Neck present, body long and narrow |
| Poison gland present; no nuchal crest | No poison gland; nuchal crest present |
(c)(i) Sex of specimen U: male.
(c)(ii) Two reasons: it is brightly coloured with a red head and blue-black trunk with an orange/blue tail; and it bears a prominent nuchal crest and gular fold, which are features of the male agama.
(d) Four features that adapt specimen S (toad) to its habitat: a poison gland in the warty skin for protection against predators; webbed hind digits for swimming in water; long, muscular hind limbs for jumping and hopping on land; and a cryptic (warty, dull) skin colour for camouflage. The moist skin also aids cutaneous respiration.
(e) Food chain (at least three specimens):
Specimen T (grass) → Specimen W (locust) → Specimen S (toad) → Specimen V (hawk).
An alternative valid chain is: Specimen T (grass) → Specimen W (locust) → Specimen U (lizard).
Pregunta 2 Informe
Study specimens H, K, L and M and answer questions 2 (a) to 2 (e).
(a) Name the location of each of the specimens H, K and M in the body of a mammal.
(b)(i) Name the fluid in specimen L (ii) State two functions of the fluid named in 2 (b) (i). (iii) Which of the other specimens is specimen L associated with?
(c)(i) State two observable differences between specimens H and K. (i) State two observable features of specimen K that adapt it to its function.
State one biological importance each of specimens K and M.
(d) Make a drawing 8 cm -10 cm long, of specimen M and label fully.
(a) Location of specimens H, K and M in the body of a mammal
- Specimen H (liver): lies just below the diaphragm, in the upper part of the abdominal cavity (abdomen).
- Specimen K (lung): lies in the thoracic cavity (chest/thorax).
- Specimen M (kidney): attached to the dorsal (back) wall of the abdominal cavity.
(b)(i) Fluid in specimen L: bile.
(b)(ii) Two functions of the bile:
- It emulsifies fats and oils into tiny fat droplets, increasing the surface area for the action of the enzyme lipase.
- Its inorganic (alkaline) salts neutralise the acidic chyme leaving the stomach, providing a suitable alkaline medium for the pancreatic and intestinal enzymes to act.
(b)(iii) Specimen L (bile) is associated with specimen H (the liver), which secretes it.
(c)(i) Two observable differences between specimens H and K
| Specimen H (liver) | Specimen K (lung) |
|---|---|
| Solid, firm and turgid in texture | Soft, spongy and fluffy in texture |
| Dark red / reddish-brown in colour | Brighter pink / red in colour |
(c)(ii) Two observable features of specimen K (lung) that adapt it to its function:
- A thin, moist surface membrane over which respiratory gases dissolve and diffuse rapidly.
- A rich supply of blood capillaries (highly vascularised) that quickly transports the exchanged gases to and from the surface.
(c)(iii) One biological importance each of specimens K and M:
- Specimen K (lung): provides the surface for breathing (inspiration and expiration) and gaseous exchange during respiration.
- Specimen M (kidney): carries out osmoregulation and the production of urine, excreting metabolic waste and maintaining the body's acid-base (water and salt) balance.
(d) Drawing of specimen M (kidney), 8 cm to 10 cm long, fully labelled
The diagram below is a longitudinal section of the kidney (specimen M), drawn to the required size and labelled fully.
Detalles de la respuesta
(a) Location of specimens H, K and M in the body of a mammal
- Specimen H (liver): lies just below the diaphragm, in the upper part of the abdominal cavity (abdomen).
- Specimen K (lung): lies in the thoracic cavity (chest/thorax).
- Specimen M (kidney): attached to the dorsal (back) wall of the abdominal cavity.
(b)(i) Fluid in specimen L: bile.
(b)(ii) Two functions of the bile:
- It emulsifies fats and oils into tiny fat droplets, increasing the surface area for the action of the enzyme lipase.
- Its inorganic (alkaline) salts neutralise the acidic chyme leaving the stomach, providing a suitable alkaline medium for the pancreatic and intestinal enzymes to act.
(b)(iii) Specimen L (bile) is associated with specimen H (the liver), which secretes it.
(c)(i) Two observable differences between specimens H and K
| Specimen H (liver) | Specimen K (lung) |
|---|---|
| Solid, firm and turgid in texture | Soft, spongy and fluffy in texture |
| Dark red / reddish-brown in colour | Brighter pink / red in colour |
(c)(ii) Two observable features of specimen K (lung) that adapt it to its function:
- A thin, moist surface membrane over which respiratory gases dissolve and diffuse rapidly.
- A rich supply of blood capillaries (highly vascularised) that quickly transports the exchanged gases to and from the surface.
(c)(iii) One biological importance each of specimens K and M:
- Specimen K (lung): provides the surface for breathing (inspiration and expiration) and gaseous exchange during respiration.
- Specimen M (kidney): carries out osmoregulation and the production of urine, excreting metabolic waste and maintaining the body's acid-base (water and salt) balance.
(d) Drawing of specimen M (kidney), 8 cm to 10 cm long, fully labelled
The diagram below is a longitudinal section of the kidney (specimen M), drawn to the required size and labelled fully.
Pregunta 3 Informe
(a)(i) Cut a pieces of specimen A, place it on the white tile. Add a few drops of iodine solution. Record the observation and result in a tabular form.
(ii) Squeeze a few drops of specimen E on another clean white tile provided, add a few dre Record the observation and result in a tabular form.
(b)(i) State two observables differences between specimens A and B. (ii) Suggest two factors that are likely to be responsible for the state of specimen B.
(iii) With the aid of hand lens/magnifying lens, observe.specimen B. and name an organism that is likely growing on it. (iv) State the mode of feeding of the organism on specimen B (c) ) Make a drawing 6cm-8 cm long, of specimen C and label fully. one function each of any three parts labeled.
(a)(i) Iodine test on specimen A (bread)
| Test | Observation | Result (inference) |
|---|---|---|
| A piece of specimen A is placed on the white tile and a few drops of iodine solution are added | The brown iodine solution turns blue-black | Starch is present in specimen A |
(a)(ii) Iodine test on specimen E (orange juice)
| Test | Observation | Result (inference) |
|---|---|---|
| A few drops of specimen E are squeezed onto a clean white tile and a few drops of iodine solution are added | The iodine solution remains brownish / yellowish (no colour change) | Starch is absent in specimen E |
(b)(i) Two observable differences between specimens A and B
| Specimen A (fresh bread) | Specimen B (stale bread) |
|---|---|
| White / cream in colour | Dark brown / black in colour |
| Soft in texture, fresh, with no mould | Hard in texture, stale / decaying, bearing mould (Rhizopus / Mucor) |
(b)(ii) Two factors likely responsible for the state of specimen B
- Presence of moisture / humidity.
- Presence of warmth (a suitable temperature), together with fungal spores acting over time, which allowed micro-organisms to grow and spoil the bread.
(b)(iii) Organism likely growing on specimen B
A mould (fungus), for example Rhizopus (bread mould) or Mucor.
(b)(iv) Mode of feeding of the organism
Saprophytic: it feeds on the dead organic matter of the bread by secreting enzymes for external (extracellular) digestion and then absorbing the digested nutrients.
(c) Drawing of specimen C (boiled egg)
Below is a labelled drawing, 6 cm to 8 cm long, of the longitudinal section of the boiled egg (specimen C).
(ii) One function of any three labelled parts
| Labelled part | Function |
|---|---|
| Shell | Protects the egg and its contents, gives shape and allows gaseous exchange (aeration) |
| Albumen (egg white) | Supplies protein and water to, and cushions, the developing embryo |
| Yolk | Stores food (fat and protein) for the growth and nourishment of the embryo |
Other parts labelled include the shell membrane and the air space, both of which aid gaseous exchange for the embryo.
Detalles de la respuesta
(a)(i) Iodine test on specimen A (bread)
| Test | Observation | Result (inference) |
|---|---|---|
| A piece of specimen A is placed on the white tile and a few drops of iodine solution are added | The brown iodine solution turns blue-black | Starch is present in specimen A |
(a)(ii) Iodine test on specimen E (orange juice)
| Test | Observation | Result (inference) |
|---|---|---|
| A few drops of specimen E are squeezed onto a clean white tile and a few drops of iodine solution are added | The iodine solution remains brownish / yellowish (no colour change) | Starch is absent in specimen E |
(b)(i) Two observable differences between specimens A and B
| Specimen A (fresh bread) | Specimen B (stale bread) |
|---|---|
| White / cream in colour | Dark brown / black in colour |
| Soft in texture, fresh, with no mould | Hard in texture, stale / decaying, bearing mould (Rhizopus / Mucor) |
(b)(ii) Two factors likely responsible for the state of specimen B
- Presence of moisture / humidity.
- Presence of warmth (a suitable temperature), together with fungal spores acting over time, which allowed micro-organisms to grow and spoil the bread.
(b)(iii) Organism likely growing on specimen B
A mould (fungus), for example Rhizopus (bread mould) or Mucor.
(b)(iv) Mode of feeding of the organism
Saprophytic: it feeds on the dead organic matter of the bread by secreting enzymes for external (extracellular) digestion and then absorbing the digested nutrients.
(c) Drawing of specimen C (boiled egg)
Below is a labelled drawing, 6 cm to 8 cm long, of the longitudinal section of the boiled egg (specimen C).
(ii) One function of any three labelled parts
| Labelled part | Function |
|---|---|
| Shell | Protects the egg and its contents, gives shape and allows gaseous exchange (aeration) |
| Albumen (egg white) | Supplies protein and water to, and cushions, the developing embryo |
| Yolk | Stores food (fat and protein) for the growth and nourishment of the embryo |
Other parts labelled include the shell membrane and the air space, both of which aid gaseous exchange for the embryo.
