(a) Study carefully specimens A, B, C, and D. copy and complete the table below
Specimen
Part modified to form specimen
Mode of propagation
Stored material
A
B
C
D
(b) In a tabular form state four observable differences between specimens A and C.
(c) Crush a small portion of specimen D and divide it into three equal parts. (i) Place a portion on a white tile and add two (2) drops of iodine solution.
(ii) Place another portion in a test tube and add one (1) ml of distilled water and shake. Add few drops of sodium hydroxide solution and shake again. Slowly add a few drop of 1% Copper (ii) sulphate solution. (iii) Smear the third part on a filter paper, leave for about five (5) minutes and observe carefully
The specimens are organs of vegetative propagation. A common WAEC set is: A, onion; B, ginger; C, Irish potato; D, cassava. The completed table follows that reading.
(a) Completed table
Specimen
Part modified to form specimen
Mode of propagation
Stored material
A (Onion)
Modified leaves (fleshy leaf bases) forming a bulb
By bulb
Carbohydrate (sugar) / starch
B (Ginger)
Modified underground stem (rhizome)
By rhizome
Starch
C (Irish potato)
Modified underground stem (stem tuber)
By stem tuber
Starch
D (Cassava)
Modified root (root tuber)
By root tuber / stem cutting
Starch
(b) Four observable differences between specimen A (onion bulb) and specimen C (potato stem tuber)
Specimen A (onion)
Specimen C (Irish potato)
Formed from modified leaves
Formed from a modified stem
Made of concentric fleshy scale leaves
Is a single swollen solid structure
Has one main (terminal) bud
Has several buds (eyes) scattered over its surface
Food is stored in the fleshy leaf bases
Food is stored in the swollen stem tissue
(c) Tests on the crushed specimen D (cassava)
Test
Observation
Inference
(i) Portion + two drops of iodine solution
Turns blue-black
Starch is present
(ii) Portion + distilled water + sodium hydroxide + copper (II) sulphate
Remains blue (no purple colour)
Protein is absent (or present in only a trace)
(iii) Portion smeared on filter paper, left five minutes
The specimens are organs of vegetative propagation. A common WAEC set is: A, onion; B, ginger; C, Irish potato; D, cassava. The completed table follows that reading.
(a) Completed table
Specimen
Part modified to form specimen
Mode of propagation
Stored material
A (Onion)
Modified leaves (fleshy leaf bases) forming a bulb
By bulb
Carbohydrate (sugar) / starch
B (Ginger)
Modified underground stem (rhizome)
By rhizome
Starch
C (Irish potato)
Modified underground stem (stem tuber)
By stem tuber
Starch
D (Cassava)
Modified root (root tuber)
By root tuber / stem cutting
Starch
(b) Four observable differences between specimen A (onion bulb) and specimen C (potato stem tuber)
Specimen A (onion)
Specimen C (Irish potato)
Formed from modified leaves
Formed from a modified stem
Made of concentric fleshy scale leaves
Is a single swollen solid structure
Has one main (terminal) bud
Has several buds (eyes) scattered over its surface
Food is stored in the fleshy leaf bases
Food is stored in the swollen stem tissue
(c) Tests on the crushed specimen D (cassava)
Test
Observation
Inference
(i) Portion + two drops of iodine solution
Turns blue-black
Starch is present
(ii) Portion + distilled water + sodium hydroxide + copper (II) sulphate
Remains blue (no purple colour)
Protein is absent (or present in only a trace)
(iii) Portion smeared on filter paper, left five minutes
Carefully study specimens J and K and answer questions 4(a) to 4(d).
(a) Name the type of refuse in specimens: (i) J (ii) K.
(b) List three animal vectors of disease causing organisms that breed on a each of specimens J ana K.
(ii) Name four diseases each caused by animal vectors associated with each or specimen J and K.
(c) Name one method of disposal of each of specimens J and K in: (i) rural areas (ii) urban areas.
(d)(i)State four effects of improper disposal of specimen K
(ii) In a tabular form. state five differences between specimens J and K.
(iii) outline one way in which specimen J is of importance to farmers.
(a) Type of refuse: (i) Specimen J is dry refuse (solid waste). (ii) Specimen K is wet refuse (sewage / liquid waste).
(b)(i) Three animal vectors that breed on each: On J - housefly, cockroach and rat. On K - housefly, mosquito (female Anopheles or Aedes) and snail.
(b)(ii) Four diseases spread by the vectors of each: Associated with J - typhoid, cholera, dysentery and diarrhoea. Associated with K - malaria, yellow fever, bilharzia (schistosomiasis) and elephantiasis.
(c) One method of disposal of each: (i) Rural areas - J: refuse dump / burying / composting; K: pit latrine / soakaway pit. (ii) Urban areas - J: sanitary landfill / incineration; K: septic tank and sewage treatment.
(d)(i) Four effects of improper disposal of specimen K (sewage): contamination of water bodies (water pollution); offensive odour; source and spread of diseases; pollution of the soil.
(d)(ii) Five differences between specimens J and K:
Specimen J (dry refuse)
Specimen K (wet refuse / sewage)
Dry solid waste
Wet liquid waste
Contains little or no water
Contains a large proportion of water
Can be kept for a long period
Cannot be kept for long
Can be burnt
Cannot be burnt
Can be compacted / compressed
Cannot be compacted
(d)(iii) One way specimen J is of importance to farmers: when buried or composted it decays into organic manure that enriches the soil and improves its fertility.
(a) Type of refuse: (i) Specimen J is dry refuse (solid waste). (ii) Specimen K is wet refuse (sewage / liquid waste).
(b)(i) Three animal vectors that breed on each: On J - housefly, cockroach and rat. On K - housefly, mosquito (female Anopheles or Aedes) and snail.
(b)(ii) Four diseases spread by the vectors of each: Associated with J - typhoid, cholera, dysentery and diarrhoea. Associated with K - malaria, yellow fever, bilharzia (schistosomiasis) and elephantiasis.
(c) One method of disposal of each: (i) Rural areas - J: refuse dump / burying / composting; K: pit latrine / soakaway pit. (ii) Urban areas - J: sanitary landfill / incineration; K: septic tank and sewage treatment.
(d)(i) Four effects of improper disposal of specimen K (sewage): contamination of water bodies (water pollution); offensive odour; source and spread of diseases; pollution of the soil.
(d)(ii) Five differences between specimens J and K:
Specimen J (dry refuse)
Specimen K (wet refuse / sewage)
Dry solid waste
Wet liquid waste
Contains little or no water
Contains a large proportion of water
Can be kept for a long period
Cannot be kept for long
Can be burnt
Cannot be burnt
Can be compacted / compressed
Cannot be compacted
(d)(iii) One way specimen J is of importance to farmers: when buried or composted it decays into organic manure that enriches the soil and improves its fertility.
Study carefully specimen E and F and use them to answer questions 2(a) to 2(d).
(a) (i) What class of organism do specimen E and F belong to?
(ii) State three similarities between specimen E and F.
(iii) In a tabular form, state three differences between specimens E and F;
(b) State two ways each in which: (i) Specimen E (ii) Specimen F are of economic importance.
(C)(i) State one observable feature each of specimens E and F and how these features adapt the specimens against predation.
(ii) Name the habitats of specimens E and F.
(d) Remove all the wings of specimen E. Make a drawing 8-10 cm long of the dorsal view of specimen E and label fully.
(a)(i) Class of organism: Specimens E and F both belong to Class Insecta.
(a)(ii) Three similarities between specimen E and F:
Both have three pairs of jointed legs (six legs).
Both have the body divided into head, thorax and abdomen (segmented body) and possess a pair of antennae with mandibulate (biting) mouthparts.
Both are bilaterally symmetrical with jointed appendages.
(a)(iii) Three differences between specimens E and F:
Specimen E (Cockroach)
Specimen F (Soldier termite)
Head small relative to the body
Head large relative to the body
Wings present
Wings absent
Compound eyes present (has sight)
No eyes (blind)
Dark brown colour; small mandibles
Light brown colour; large mandibles
(b) Economic importance
(i) Specimen E (cockroach): destroys clothes, books and stored materials; contaminates food, reduces its quality and gives it a foul odour; serves as a vector (carrier) of disease-causing organisms.
(ii) Specimen F (soldier termite): speeds up decay by breaking down dead wood into humus, which increases soil fertility and improves soil drainage and aeration through its channels; it is a source of protein for poultry feed, and mud from the termitarium is used for building; however, it also destroys wood in roofs, houses, furniture, timber and crops.
(c)(i) Observable feature adapting each specimen against predation:
Specimen E (cockroach): its dorso-ventrally flattened body lets it hide quickly in cracks and crevices, and its brown colour blends with the surroundings as camouflage; its wings also allow it to fly away from predators.
Specimen F (soldier termite): its large, strong mandibles are used to bite in defence, and the snout-like projection of the head produces a poisonous defensive secretion for protection.
(c)(ii) Habitats: Specimen E (cockroach) lives in dark boxes, cupboards and cesspits; Specimen F (soldier termite) lives in the termitarium (termite mound/hill).
(d) Drawing of the dorsal view of Specimen E (cockroach) with all wings removed, 8-10 cm long, fully labelled:
Dorsal view of specimen E (cockroach) with the wings removed, fully labelled.
(a)(i) Class of organism: Specimens E and F both belong to Class Insecta.
(a)(ii) Three similarities between specimen E and F:
Both have three pairs of jointed legs (six legs).
Both have the body divided into head, thorax and abdomen (segmented body) and possess a pair of antennae with mandibulate (biting) mouthparts.
Both are bilaterally symmetrical with jointed appendages.
(a)(iii) Three differences between specimens E and F:
Specimen E (Cockroach)
Specimen F (Soldier termite)
Head small relative to the body
Head large relative to the body
Wings present
Wings absent
Compound eyes present (has sight)
No eyes (blind)
Dark brown colour; small mandibles
Light brown colour; large mandibles
(b) Economic importance
(i) Specimen E (cockroach): destroys clothes, books and stored materials; contaminates food, reduces its quality and gives it a foul odour; serves as a vector (carrier) of disease-causing organisms.
(ii) Specimen F (soldier termite): speeds up decay by breaking down dead wood into humus, which increases soil fertility and improves soil drainage and aeration through its channels; it is a source of protein for poultry feed, and mud from the termitarium is used for building; however, it also destroys wood in roofs, houses, furniture, timber and crops.
(c)(i) Observable feature adapting each specimen against predation:
Specimen E (cockroach): its dorso-ventrally flattened body lets it hide quickly in cracks and crevices, and its brown colour blends with the surroundings as camouflage; its wings also allow it to fly away from predators.
Specimen F (soldier termite): its large, strong mandibles are used to bite in defence, and the snout-like projection of the head produces a poisonous defensive secretion for protection.
(c)(ii) Habitats: Specimen E (cockroach) lives in dark boxes, cupboards and cesspits; Specimen F (soldier termite) lives in the termitarium (termite mound/hill).
(d) Drawing of the dorsal view of Specimen E (cockroach) with all wings removed, 8-10 cm long, fully labelled:
Dorsal view of specimen E (cockroach) with the wings removed, fully labelled.
