WAEC SSCE - Biology - 2021 (Practical)
Swali 1 Ripoti
Beakers D, E, F and G contain seeds that have been sown for seven days. Carefully remove one seed/seedling from each of the beakers labelled D, E, F and place each on the corresponding white tile labelled D, E, F and G. Study them and answer questions 2(a) to 2(c). (a) Observe the soils and seed/seedling then record the observation and result on the table below.
(b)(i) Name one condition for germination that was likely absent in the beakers labelled E, F and G
E: _________ F: _________ G: _________
(ii) Give two reasons for the result in beaker D.
(c) Make a drawing 8cm to 10cm long of one sees/seedling obtained from the beaker labelled D and label fully.
Beakers D, E, F and G form a germination experiment. Beaker D is the control in which a viable seed is supplied with all the requirements for germination (water, oxygen, suitable warmth). In each of E, F and G one requirement is withheld, so germination fails in those three and succeeds only in D.
(a) Observation and result
| Beaker | Observation | Result |
|---|---|---|
| D | Soil moist; seed has swollen, and a radicle (young root) and plumule (young shoot) have emerged | Germination occurred |
| E | Soil moist and warm, but the seed remains unchanged and later decays | No germination |
| F | Seed fully submerged under water and cut off from air; seed remains unchanged | No germination |
| G | Soil dry; seed remains hard and shrivelled | No germination |
(b)(i) Condition for germination likely absent
E: a viable seed (the seed was dead / non-viable).
F: oxygen / air (the seed was drowned under water).
G: moisture / water (the soil was dry).
(b)(ii) Two reasons for the result in beaker D
- All the conditions necessary for germination - water, oxygen (air), suitable warmth and a viable seed - were present together.
- It is the control experiment, in which nothing is withheld, so the embryo was able to grow normally into a seedling.
(c) Drawing of one seedling from beaker D
The seedling below is drawn large (about 9 cm long, within the 8-10 cm range required) and fully labelled.
Title: A germinated bean seedling from beaker D (epigeal germination).
Maelezo ya Majibu
Beakers D, E, F and G form a germination experiment. Beaker D is the control in which a viable seed is supplied with all the requirements for germination (water, oxygen, suitable warmth). In each of E, F and G one requirement is withheld, so germination fails in those three and succeeds only in D.
(a) Observation and result
| Beaker | Observation | Result |
|---|---|---|
| D | Soil moist; seed has swollen, and a radicle (young root) and plumule (young shoot) have emerged | Germination occurred |
| E | Soil moist and warm, but the seed remains unchanged and later decays | No germination |
| F | Seed fully submerged under water and cut off from air; seed remains unchanged | No germination |
| G | Soil dry; seed remains hard and shrivelled | No germination |
(b)(i) Condition for germination likely absent
E: a viable seed (the seed was dead / non-viable).
F: oxygen / air (the seed was drowned under water).
G: moisture / water (the soil was dry).
(b)(ii) Two reasons for the result in beaker D
- All the conditions necessary for germination - water, oxygen (air), suitable warmth and a viable seed - were present together.
- It is the control experiment, in which nothing is withheld, so the embryo was able to grow normally into a seedling.
(c) Drawing of one seedling from beaker D
The seedling below is drawn large (about 9 cm long, within the 8-10 cm range required) and fully labelled.
Title: A germinated bean seedling from beaker D (epigeal germination).
Swali 2 Ripoti
Study specimen A (Neck region/neck), B (Chest region/thoracic region/thorax) and C(Upper abdominal region/upper abdomen) and answer questiions 1(a) to 1(c).
(a)(i) Name the part of the body where specimens A, B and C would be found in a mammal. A: _________ B: _________ C: __________
(ii) State one function each of specimens A, B and C. A: ________ B: _________ C: _________
(b)(i) Make a drawing , 6cm to 8cm long of the anterior view of specimen C and label fully. (ii) State one function each of four of the parts labelled in 1(b)(i).
(c)(i) Mention the total number of each of specimens A, B and C in adult humans . A: _________ B: _________ C: _________ (ii) Name two other vertebrae in humans.
(a)(i) Part of the body where each specimen is found in a mammal
| Specimen | Identity | Region of the body |
| A | Cervical vertebra | Neck region |
| B | Thoracic vertebra | Chest / thoracic region |
| C | Lumbar vertebra | Upper abdominal / lower back region |
(a)(ii) One function of each specimen
- A (cervical vertebra): supports the head and provides a passage that protects the spinal cord as it leaves the skull.
- B (thoracic vertebra): articulates with the rib bones and provides a surface for the attachment of chest muscles while protecting the spinal cord.
- C (lumbar vertebra): bears the weight of the body and permits bending and rotation of the trunk.
(b)(i) Drawing of the anterior view of specimen C (lumbar vertebra), fully labelled
(b)(ii) One function of each of four labelled parts
- Neural spine: gives attachment to the back and abdominal muscles.
- Transverse process: gives a surface for the attachment of muscles.
- Neural canal: encloses and houses the spinal cord.
- Centrum (body): bears the weight of the body and provides mechanical support.
(c)(i) Total number of each specimen in adult humans
| Specimen | Total number |
| A (cervical vertebrae) | 7 |
| B (thoracic vertebrae) | 12 |
| C (lumbar vertebrae) | 5 |
(c)(ii) Two other vertebrae in humans: the sacral vertebrae (sacrum) and the coccygeal vertebrae (coccyx / caudal vertebrae).
Maelezo ya Majibu
(a)(i) Part of the body where each specimen is found in a mammal
| Specimen | Identity | Region of the body |
| A | Cervical vertebra | Neck region |
| B | Thoracic vertebra | Chest / thoracic region |
| C | Lumbar vertebra | Upper abdominal / lower back region |
(a)(ii) One function of each specimen
- A (cervical vertebra): supports the head and provides a passage that protects the spinal cord as it leaves the skull.
- B (thoracic vertebra): articulates with the rib bones and provides a surface for the attachment of chest muscles while protecting the spinal cord.
- C (lumbar vertebra): bears the weight of the body and permits bending and rotation of the trunk.
(b)(i) Drawing of the anterior view of specimen C (lumbar vertebra), fully labelled
(b)(ii) One function of each of four labelled parts
- Neural spine: gives attachment to the back and abdominal muscles.
- Transverse process: gives a surface for the attachment of muscles.
- Neural canal: encloses and houses the spinal cord.
- Centrum (body): bears the weight of the body and provides mechanical support.
(c)(i) Total number of each specimen in adult humans
| Specimen | Total number |
| A (cervical vertebrae) | 7 |
| B (thoracic vertebrae) | 12 |
| C (lumbar vertebrae) | 5 |
(c)(ii) Two other vertebrae in humans: the sacral vertebrae (sacrum) and the coccygeal vertebrae (coccyx / caudal vertebrae).
Swali 3 Ripoti
Study specimens L and M and answer questions (a) to (e).
(a) Classify each of specimens L and M into its:
(i) Phylum L: ________ M: _______
(ii) Class L:_______ M:_______
(b)
(i) State three observable features of members of the class of specimen L.
(ii) Name three other classes of the phylum to which specimen L belongs.
(c)
(i) State two ways each by which specimens L and M are of economic importance. L: _______ M: ________
(ii) State five ways by which specimen L can be controlled.
(d)(i) State five observable differences between specimens L and M.
(ii) State four observable similarities between specimens L and M.
(e) Name one habitat each of specimens L and M. L:_______ M:_______
(a) Classification
| Specimen L (mosquito) | Specimen M (butterfly) | |
|---|---|---|
| (i) Phylum | Arthropoda | Arthropoda |
| (ii) Class | Insecta | Insecta |
(b)(i) Three observable features of the class Insecta: body divided into head, thorax and abdomen; three pairs of jointed walking legs; a pair of jointed antennae (also wings, compound eyes and a chitinous exoskeleton).
(b)(ii) Three other classes of Phylum Arthropoda: Crustacea, Arachnida and Chilopoda (or Diplopoda).
(c)(i) Two ways each is of economic importance
- L (mosquito): it is a vector that transmits diseases such as malaria, and its bites cause discomfort and disturb rest.
- M (butterfly): it pollinates flowers and has aesthetic (ornamental) value, though its larvae destroy crops such as citrus by feeding on them.
(c)(ii) Five ways specimen L (mosquito) can be controlled
- Removing all stagnant water around the house to prevent breeding.
- Pouring oil on stagnant water to suffocate the larvae and pupae.
- Spraying insecticides in and around the rooms to kill adult mosquitoes.
- Clearing bushes around the house to remove hiding and breeding places.
- Sleeping under treated mosquito nets to prevent bites.
(d)(i) Five observable differences between specimens L and M
| Specimen L (mosquito) | Specimen M (butterfly) |
|---|---|
| Small, slender body | Larger, broader body |
| One pair of narrow, transparent wings | Two pairs of broad wings covered with coloured scales |
| Dull greyish colour | Brightly coloured, patterned |
| Feathery (plumose) antennae | Clubbed antennae |
| Proboscis is slender and piercing | Proboscis is long and coiled for sucking nectar |
(d)(ii) Four observable similarities between L and M: both have the body in three divisions (head, thorax and abdomen); both have three pairs of legs and one pair of antennae; both possess wings and a pair of compound eyes; both have a chitinous exoskeleton and a proboscis for feeding.
(e) One habitat each: L (mosquito): damp, dark places near stagnant water. M (butterfly): gardens and grassland among flowering plants.
Maelezo ya Majibu
(a) Classification
| Specimen L (mosquito) | Specimen M (butterfly) | |
|---|---|---|
| (i) Phylum | Arthropoda | Arthropoda |
| (ii) Class | Insecta | Insecta |
(b)(i) Three observable features of the class Insecta: body divided into head, thorax and abdomen; three pairs of jointed walking legs; a pair of jointed antennae (also wings, compound eyes and a chitinous exoskeleton).
(b)(ii) Three other classes of Phylum Arthropoda: Crustacea, Arachnida and Chilopoda (or Diplopoda).
(c)(i) Two ways each is of economic importance
- L (mosquito): it is a vector that transmits diseases such as malaria, and its bites cause discomfort and disturb rest.
- M (butterfly): it pollinates flowers and has aesthetic (ornamental) value, though its larvae destroy crops such as citrus by feeding on them.
(c)(ii) Five ways specimen L (mosquito) can be controlled
- Removing all stagnant water around the house to prevent breeding.
- Pouring oil on stagnant water to suffocate the larvae and pupae.
- Spraying insecticides in and around the rooms to kill adult mosquitoes.
- Clearing bushes around the house to remove hiding and breeding places.
- Sleeping under treated mosquito nets to prevent bites.
(d)(i) Five observable differences between specimens L and M
| Specimen L (mosquito) | Specimen M (butterfly) |
|---|---|
| Small, slender body | Larger, broader body |
| One pair of narrow, transparent wings | Two pairs of broad wings covered with coloured scales |
| Dull greyish colour | Brightly coloured, patterned |
| Feathery (plumose) antennae | Clubbed antennae |
| Proboscis is slender and piercing | Proboscis is long and coiled for sucking nectar |
(d)(ii) Four observable similarities between L and M: both have the body in three divisions (head, thorax and abdomen); both have three pairs of legs and one pair of antennae; both possess wings and a pair of compound eyes; both have a chitinous exoskeleton and a proboscis for feeding.
(e) One habitat each: L (mosquito): damp, dark places near stagnant water. M (butterfly): gardens and grassland among flowering plants.
