WAEC SSCE - Biology - 2022 (Essay)
Question 1 Report
Study specimens H, K, L, M and N and answer questions (a) to (f).
(a) State two observable structural differences between: (i) specimens H and L; (ii) specimens K and M.
(b)(i) State two ways each by which specimens H and M adapt the organisms to their modes of life. (ii) Name two types of food that the organism that possesses specimen H feeds on.
(c) Make a drawing, 8 cm to 10 cm long, of specimen K.
(d) Name one habitat of the organism that possesses specimen K.
(e) Name one feeding habit of each of the organisms that possesses specimen H and L.
(f) State two observable similarities between specimens: (i) H and L; (ii) K and M.
(a)
(i) Specimens H and L
- H has a short, stout, conical beak, whereas L has a long, slender, pointed beak.
- H has strong feet with claws suited for scratching the ground, whereas L has feet adapted mainly for perching.
(ii) Specimens K and M
- K has fins, whereas M has paddle-like flippers.
- K has a scaly body covering, whereas M has a smooth skin without scales.
(b)(i) Adaptations
| Specimen | Adaptive features |
|---|---|
| H | Its short, strong conical beak is used for picking and cracking seeds. Its strong clawed feet enable it to scratch the ground in search of food. |
| M | Its streamlined body reduces resistance while moving in water. Its flippers and powerful tail aid swimming and propulsion. |
(b)(ii) The organism possessing specimen H feeds on seeds or grains and insects.
(c) Drawing of specimen K, showing a fish about 8 cm to 10 cm long.
(d) One habitat of the organism possessing specimen K is a freshwater pond.
(e)
| Specimen | Feeding habit |
|---|---|
| H | Granivorous or seed-feeding. |
| L | Insectivorous. |
(f)
(i) H and L: Both have beaks, and both possess feathers and wings.
(ii) K and M: Both have streamlined bodies, and both have tails used in movement through water.
Answer Details
(a)
(i) Specimens H and L
- H has a short, stout, conical beak, whereas L has a long, slender, pointed beak.
- H has strong feet with claws suited for scratching the ground, whereas L has feet adapted mainly for perching.
(ii) Specimens K and M
- K has fins, whereas M has paddle-like flippers.
- K has a scaly body covering, whereas M has a smooth skin without scales.
(b)(i) Adaptations
| Specimen | Adaptive features |
|---|---|
| H | Its short, strong conical beak is used for picking and cracking seeds. Its strong clawed feet enable it to scratch the ground in search of food. |
| M | Its streamlined body reduces resistance while moving in water. Its flippers and powerful tail aid swimming and propulsion. |
(b)(ii) The organism possessing specimen H feeds on seeds or grains and insects.
(c) Drawing of specimen K, showing a fish about 8 cm to 10 cm long.
(d) One habitat of the organism possessing specimen K is a freshwater pond.
(e)
| Specimen | Feeding habit |
|---|---|
| H | Granivorous or seed-feeding. |
| L | Insectivorous. |
(f)
(i) H and L: Both have beaks, and both possess feathers and wings.
(ii) K and M: Both have streamlined bodies, and both have tails used in movement through water.
Question 2 Report
Answer Details
Question 3 Report
5.(a) State three differences between the alimentary canals of earthworm and cockroach.
(i) State three similarities between the alimentary canals of earthworm and cockroach.
(b) The diagram below is an illustration of a biological cycle.
Study it and answer questions 5(b)i) to 5(b)(iii)
[i]Name the biological cycle (i) Explain briefly three roles played by plants and animals in the cycle (ii) Name the process that occur in X, Y and Z.
c. complete the table below.
| organs associated with excretion in human | three diseases that affect the organ |
(d)i) What is decay of organic matter
(i) Name two groups of organisms that cause decay of organic matter.
(i) State one other factor that causes decay.
(iv) Name the biological cycle that involves decay.
(e) Explain briefly the mode of nutrition in carnivorous plants.
(a) Three differences between the alimentary canals of the earthworm and the cockroach:
| Earthworm | Cockroach |
|---|---|
| Canal is a straight tube from mouth to anus | Canal is a longer, more differentiated tube |
| Possesses a calciferous gland | Has no calciferous gland |
| Lacks gastric caeca | Possesses gastric caeca that secrete digestive enzymes |
| Has a typhlosole to increase absorptive surface of the intestine | Has no typhlosole |
Three similarities: both have a mouth, both have a muscular gizzard for grinding food, and both have a complete (one-way) alimentary canal ending in an anus with a distinct crop for storage.
(b)
(i) The biological cycle illustrated is the carbon cycle (carbon dioxide - oxygen cycle).
(ii) Three roles played by plants and animals in the cycle:
- Green plants take in carbon dioxide during photosynthesis and fix it into organic food, removing carbon dioxide from the air.
- Plants and animals release carbon dioxide back into the air during respiration.
- When plants and animals die, their bodies are decomposed, releasing carbon dioxide; animals also transfer carbon along food chains by feeding on plants.
(iii) Processes: X - photosynthesis, Y - respiration, Z - decay (decomposition) / combustion.
(c) Organs of excretion in humans and diseases affecting them:
| Excretory organ | Three diseases affecting the organ |
|---|---|
| Kidney | Nephritis, kidney stones, kidney failure |
| Skin | Eczema, scabies, ringworm |
| Lungs | Pneumonia, tuberculosis, bronchitis |
| Liver | Hepatitis, liver cirrhosis, jaundice |
(d)
(i) Decay of organic matter is the breaking down of dead plant and animal tissues into simpler substances by the action of micro-organisms.
(ii) Two groups of organisms that cause decay: bacteria and fungi.
(iii) One other factor that causes decay: suitable warmth (temperature); also moisture and oxygen.
(iv) The biological cycle that involves decay: the carbon cycle (and the nitrogen cycle).
(e) Carnivorous plants are green and carry out photosynthesis to make carbohydrates, but they grow in nitrogen-deficient soils. They trap and digest small insects using modified leaves (traps), secreting enzymes that break down the animal protein to obtain nitrogen and other mineral nutrients. Their nutrition is therefore partly autotrophic (photosynthetic) and partly heterotrophic (holozoic on insects).
Answer Details
(a) Three differences between the alimentary canals of the earthworm and the cockroach:
| Earthworm | Cockroach |
|---|---|
| Canal is a straight tube from mouth to anus | Canal is a longer, more differentiated tube |
| Possesses a calciferous gland | Has no calciferous gland |
| Lacks gastric caeca | Possesses gastric caeca that secrete digestive enzymes |
| Has a typhlosole to increase absorptive surface of the intestine | Has no typhlosole |
Three similarities: both have a mouth, both have a muscular gizzard for grinding food, and both have a complete (one-way) alimentary canal ending in an anus with a distinct crop for storage.
(b)
(i) The biological cycle illustrated is the carbon cycle (carbon dioxide - oxygen cycle).
(ii) Three roles played by plants and animals in the cycle:
- Green plants take in carbon dioxide during photosynthesis and fix it into organic food, removing carbon dioxide from the air.
- Plants and animals release carbon dioxide back into the air during respiration.
- When plants and animals die, their bodies are decomposed, releasing carbon dioxide; animals also transfer carbon along food chains by feeding on plants.
(iii) Processes: X - photosynthesis, Y - respiration, Z - decay (decomposition) / combustion.
(c) Organs of excretion in humans and diseases affecting them:
| Excretory organ | Three diseases affecting the organ |
|---|---|
| Kidney | Nephritis, kidney stones, kidney failure |
| Skin | Eczema, scabies, ringworm |
| Lungs | Pneumonia, tuberculosis, bronchitis |
| Liver | Hepatitis, liver cirrhosis, jaundice |
(d)
(i) Decay of organic matter is the breaking down of dead plant and animal tissues into simpler substances by the action of micro-organisms.
(ii) Two groups of organisms that cause decay: bacteria and fungi.
(iii) One other factor that causes decay: suitable warmth (temperature); also moisture and oxygen.
(iv) The biological cycle that involves decay: the carbon cycle (and the nitrogen cycle).
(e) Carnivorous plants are green and carry out photosynthesis to make carbohydrates, but they grow in nitrogen-deficient soils. They trap and digest small insects using modified leaves (traps), secreting enzymes that break down the animal protein to obtain nitrogen and other mineral nutrients. Their nutrition is therefore partly autotrophic (photosynthetic) and partly heterotrophic (holozoic on insects).
Question 4 Report
Answer Details
Question 5 Report
[a]complete the table below by ticking the appropriate group to which each of the listed elements required by plants belongs
| elements | Group | |
| microelement | macroelement | |
| hydrogen | ||
| copper | ||
| magnesium | ||
| zinc | ||
| phosphorus | ||
| manganese | ||
| boron | ||
| nitrogen | ||
| carbon | ||
| oxygen | ||
[b] [!] state three differences between the definition of a herbivore and a carnivore
[!!] four differences between the definition of a human and a goat
[c] what are milk teeth?
[a]
[b] Differences between a herbivore and a carnivore:
1. Diet: Herbivores primarily consume plant material, such as leaves, grass, and fruits, while carnivores eat mainly meat or animal tissue.
2. Teeth structure: Herbivores typically have specialized teeth for grinding and chewing plant matter, such as flat molars and incisors, while carnivores have sharp teeth, including canines and carnassials, for tearing and cutting flesh.
3. Digestive system: Herbivores have a longer digestive tract to break down and extract nutrients from plant material, while carnivores have a shorter digestive system as they obtain nutrients more easily from animal tissue. Differences between a human and a goat:
1. Anatomy: Humans have an upright posture and bipedal locomotion, while goats have a four-legged stance and quadrupedal locomotion.
2. Diet: Humans are omnivorous and have a diverse diet that includes both plant and animal-based food, while goats are herbivores and primarily graze on vegetation.
3. Communication: Humans have developed complex language systems for communication, while goats primarily communicate through vocalizations, body language, and scent marking.
4. Habitat and lifestyle: Humans have a wide range of habitats and live in diverse social structures, while goats are typically found in specific regions, such as mountains or grasslands, and live in herds.
[c] Milk teeth, also known as deciduous teeth or baby teeth, are the first set of teeth that humans and many other mammals develop. These teeth begin to emerge during infancy and are eventually replaced by permanent teeth as a child grows. Milk teeth play an important role in the early stages of life. They help infants and young children chew and break down food, facilitating proper digestion. These teeth also aid in speech development, as they enable the tongue and lips to make various sounds accurately. Milk teeth are temporary, and as the child grows, they gradually loosen and fall out. This process allows space for the permanent teeth to erupt and take their place. Generally, humans have 20 milk teeth, which include incisors, canines, and molars. The transition from milk teeth to permanent teeth usually occurs between the ages of 6 and 12. During this period, children experience the natural loss of milk teeth and the emergence of their permanent teeth. The permanent teeth are larger, stronger, and meant to last throughout adulthood.
Answer Details
[a]
[b] Differences between a herbivore and a carnivore:
1. Diet: Herbivores primarily consume plant material, such as leaves, grass, and fruits, while carnivores eat mainly meat or animal tissue.
2. Teeth structure: Herbivores typically have specialized teeth for grinding and chewing plant matter, such as flat molars and incisors, while carnivores have sharp teeth, including canines and carnassials, for tearing and cutting flesh.
3. Digestive system: Herbivores have a longer digestive tract to break down and extract nutrients from plant material, while carnivores have a shorter digestive system as they obtain nutrients more easily from animal tissue. Differences between a human and a goat:
1. Anatomy: Humans have an upright posture and bipedal locomotion, while goats have a four-legged stance and quadrupedal locomotion.
2. Diet: Humans are omnivorous and have a diverse diet that includes both plant and animal-based food, while goats are herbivores and primarily graze on vegetation.
3. Communication: Humans have developed complex language systems for communication, while goats primarily communicate through vocalizations, body language, and scent marking.
4. Habitat and lifestyle: Humans have a wide range of habitats and live in diverse social structures, while goats are typically found in specific regions, such as mountains or grasslands, and live in herds.
[c] Milk teeth, also known as deciduous teeth or baby teeth, are the first set of teeth that humans and many other mammals develop. These teeth begin to emerge during infancy and are eventually replaced by permanent teeth as a child grows. Milk teeth play an important role in the early stages of life. They help infants and young children chew and break down food, facilitating proper digestion. These teeth also aid in speech development, as they enable the tongue and lips to make various sounds accurately. Milk teeth are temporary, and as the child grows, they gradually loosen and fall out. This process allows space for the permanent teeth to erupt and take their place. Generally, humans have 20 milk teeth, which include incisors, canines, and molars. The transition from milk teeth to permanent teeth usually occurs between the ages of 6 and 12. During this period, children experience the natural loss of milk teeth and the emergence of their permanent teeth. The permanent teeth are larger, stronger, and meant to last throughout adulthood.
Question 6 Report
Study specimen D and E and answer questions
(a) and (b).
(a)i Name the specific habitats of each of specimens D and E.
D:...........................................
E:...........................................
(i) State five observable structural difference between specimens D and E.
(i) What is the behavioural adaptation that specimens D and E exhibit? (b) State two ways by which specimen E is of economic importance.
Study specimen G and answer questions 2(c) to (e).
(c) On the table below, name the types of teeth present in specimen G and state one function each of the types of teeth named.
| types of teeth | one function |
(d)(i) Name the mode of feeding of the organism from which specimen G was obtained.
(ii)(d) Name the mode of feeding of the organism from which specimen G was obtained.
State three ways by which specimen G adapts its organism to the mode of feeding stated in (d)(i)
(e) Name two mineral elements which are needed for the proper functioning of specimen G in the body.
(a)(i) habitats of specimens of D and E
D: Termatarium/anthill/old logs of trees/mounds dead tree stumps
E: nest/hive
(ii) observable structural differences between specimens D and E
| D/soldier termite | E/honeybee |
| presence of prominent/large/mandible | presence of poorly developed/less prominent mandible |
| stingvabsent | sting present |
| pollen comb | wing present |
| wing absent | presence of pollen basket |
| absence of prong | presence of prong |
| absence of proboscis | presence of proboscis |
| body not hairy[smooth] | body is hairy |
| absence of eye blind | presence of [two/pair/of] compound eyes |
| big in size /big head | small in size /small head |
[iii] (iii) Behavioural adaptation common1o specimens D and E
Social insects/nuptial flight/swarming
(b) Economic importance of specimen E
a. Production of honey
b. Production of beeswax/wax
c. Pollinating agent d. Employment
e. Their stings lead to allergies/anaphylactic shock/difficulty in breathing/rashes/skin irritations
f. Their stings could lead to death.
{c} Table
| Types of teeth | one function of teeth |
| incisor | cutting of vegetation/nibbling/gnawing/biting. |
| premolar | grinding/chewing |
| molar | grinding/chewing |
d[i] mode of feeding specimens G herbivorous
ii ways by which specimen G adapts its organism to its mode of feeding
a. sharp/chisel shaped/curved incisors for cutting vegetation/leaves /food/gnawing/bibbling/bitting
b. broad/ridged surface of premolar ; for grinding /chewing
Presence of diastema/space between incisor
grinding/chewing and premolar, allows the rolling of food into bolus/its separates.freshly cut food/grass from the one being chewed.
e.Mineral element needed for the proper functioning of specimen G
i.Calcium ii. Phosphorus iii. Copper
iv.Boron v. Zinc vi. Copper
vii.Magnesium viii. Iron ix. Potassium
Answer Details
(a)(i) habitats of specimens of D and E
D: Termatarium/anthill/old logs of trees/mounds dead tree stumps
E: nest/hive
(ii) observable structural differences between specimens D and E
| D/soldier termite | E/honeybee |
| presence of prominent/large/mandible | presence of poorly developed/less prominent mandible |
| stingvabsent | sting present |
| pollen comb | wing present |
| wing absent | presence of pollen basket |
| absence of prong | presence of prong |
| absence of proboscis | presence of proboscis |
| body not hairy[smooth] | body is hairy |
| absence of eye blind | presence of [two/pair/of] compound eyes |
| big in size /big head | small in size /small head |
[iii] (iii) Behavioural adaptation common1o specimens D and E
Social insects/nuptial flight/swarming
(b) Economic importance of specimen E
a. Production of honey
b. Production of beeswax/wax
c. Pollinating agent d. Employment
e. Their stings lead to allergies/anaphylactic shock/difficulty in breathing/rashes/skin irritations
f. Their stings could lead to death.
{c} Table
| Types of teeth | one function of teeth |
| incisor | cutting of vegetation/nibbling/gnawing/biting. |
| premolar | grinding/chewing |
| molar | grinding/chewing |
d[i] mode of feeding specimens G herbivorous
ii ways by which specimen G adapts its organism to its mode of feeding
a. sharp/chisel shaped/curved incisors for cutting vegetation/leaves /food/gnawing/bibbling/bitting
b. broad/ridged surface of premolar ; for grinding /chewing
Presence of diastema/space between incisor
grinding/chewing and premolar, allows the rolling of food into bolus/its separates.freshly cut food/grass from the one being chewed.
e.Mineral element needed for the proper functioning of specimen G
i.Calcium ii. Phosphorus iii. Copper
iv.Boron v. Zinc vi. Copper
vii.Magnesium viii. Iron ix. Potassium
Question 7 Report
[c} Human and goat
| Human | Goat |
| absence of diastema | presence of diastema |
| presence of canine | absence of canine |
| presence of incisor | absence of dental pad |
| presence of eight premolar | presence of twelve premolars |
| equal number of incisors in upper and lower jaw | presence of incisors in upper and lower jaw |
Answer Details
[c} Human and goat
| Human | Goat |
| absence of diastema | presence of diastema |
| presence of canine | absence of canine |
| presence of incisor | absence of dental pad |
| presence of eight premolar | presence of twelve premolars |
| equal number of incisors in upper and lower jaw | presence of incisors in upper and lower jaw |
Question 8 Report
(a) What are conversation laws?
(i) State three conservation laws
(b) State two reasons why animals are poached.
(i) Name five animals that are commonly poached.
(c) State four effects of excessive use of the forest.
(d) Explain briefly the following terms: i.blood transfusion ii.antigen
Answer Details
Question 9 Report
(a)(i) State three differences between the alimentary canals of earthworm and cockroach. (ii) State three similarities between the alimentary canals of earthworm and cockroach.
(b) The diagram below is an illustration of a biological cycle. Study it and answer questions (b)(i) to (b)(iii).
(i) Name the biological cycle. (ii) Explain briefly three roles played by plants and animals in the cycle. (iii) Name the process that occurs at X, Y and Z.
(c) Complete the table below.
| Organs associated with excretion in human | Three diseases that affect the organ |
|---|---|
(d)(i) What is decay of organic matter? (ii) Name two groups of organisms that cause decay of organic matter. (iii) State one other factor that causes decay. (iv) Name the biological cycle that involves decay.
(e) Explain briefly the mode of nutrition in carnivorous plants.
5(a)(i) Differences between the alimentary canals of earthworm and cockroach
| Earthworm | Cockroach |
|---|---|
| The alimentary canal is almost straight, extending from the anterior mouth to the posterior anus. | The alimentary canal is coiled and is differentiated into foregut, midgut and hindgut. |
| It has no gastric caeca. | It has gastric caeca at the junction of the foregut and midgut, which secrete digestive enzymes. |
| Its intestine has a typhlosole, which increases the surface area for absorption. | Its midgut has no typhlosole; instead, it has numerous gastric caeca. |
| No Malpighian tubules open into its alimentary canal. | Malpighian tubules open into the alimentary canal at the junction of the midgut and hindgut. |
5(a)(ii) Similarities between the alimentary canals of earthworm and cockroach
- Each has a complete alimentary canal with a mouth and an anus.
- Each has a pharynx, oesophagus, crop, gizzard and intestine.
- In each, food is digested, absorbed through the gut wall and undigested materials are egested through the anus.
5(b)(i) Name of biological cycle
The cycle is the carbon cycle.
Roles of plants and animals in the carbon cycle
- Green plants remove carbon dioxide from the atmosphere during photosynthesis and convert it into organic food substances.
- Animals obtain carbon compounds by feeding on plants or on other animals.
- Plants and animals release carbon dioxide back into the atmosphere during respiration. When they die, decomposers break down their remains and return carbon compounds to the environment.
5(b)(ii) Processes occurring at X, Y and Z
| Label | Process |
|---|---|
| X | Photosynthesis |
| Y | Respiration |
| Z | Decay or decomposition |
5(c) Completed table
| Organ associated with excretion in humans | Three diseases that affect the organ |
|---|---|
| Kidney |
|
5(d)(i) Decay of organic matter is the breakdown of dead plants, dead animals and their wastes into simpler substances.
5(d)(ii) The two groups of organisms that cause decay are bacteria and fungi.
5(d)(iii) Moisture or water is one factor that promotes decay.
5(d)(iv) The biological cycle involving decay is the carbon cycle.
5(e) Carnivorous plants are mainly autotrophic because they manufacture carbohydrates by photosynthesis. However, they trap small animals, especially insects, using modified leaves such as pitchers or snap traps. Enzymes digest the trapped animals, and the plants absorb mineral salts, especially nitrogen compounds, from them. This enables the plants to survive in nitrogen-deficient soils.
Answer Details
5(a)(i) Differences between the alimentary canals of earthworm and cockroach
| Earthworm | Cockroach |
|---|---|
| The alimentary canal is almost straight, extending from the anterior mouth to the posterior anus. | The alimentary canal is coiled and is differentiated into foregut, midgut and hindgut. |
| It has no gastric caeca. | It has gastric caeca at the junction of the foregut and midgut, which secrete digestive enzymes. |
| Its intestine has a typhlosole, which increases the surface area for absorption. | Its midgut has no typhlosole; instead, it has numerous gastric caeca. |
| No Malpighian tubules open into its alimentary canal. | Malpighian tubules open into the alimentary canal at the junction of the midgut and hindgut. |
5(a)(ii) Similarities between the alimentary canals of earthworm and cockroach
- Each has a complete alimentary canal with a mouth and an anus.
- Each has a pharynx, oesophagus, crop, gizzard and intestine.
- In each, food is digested, absorbed through the gut wall and undigested materials are egested through the anus.
5(b)(i) Name of biological cycle
The cycle is the carbon cycle.
Roles of plants and animals in the carbon cycle
- Green plants remove carbon dioxide from the atmosphere during photosynthesis and convert it into organic food substances.
- Animals obtain carbon compounds by feeding on plants or on other animals.
- Plants and animals release carbon dioxide back into the atmosphere during respiration. When they die, decomposers break down their remains and return carbon compounds to the environment.
5(b)(ii) Processes occurring at X, Y and Z
| Label | Process |
|---|---|
| X | Photosynthesis |
| Y | Respiration |
| Z | Decay or decomposition |
5(c) Completed table
| Organ associated with excretion in humans | Three diseases that affect the organ |
|---|---|
| Kidney |
|
5(d)(i) Decay of organic matter is the breakdown of dead plants, dead animals and their wastes into simpler substances.
5(d)(ii) The two groups of organisms that cause decay are bacteria and fungi.
5(d)(iii) Moisture or water is one factor that promotes decay.
5(d)(iv) The biological cycle involving decay is the carbon cycle.
5(e) Carnivorous plants are mainly autotrophic because they manufacture carbohydrates by photosynthesis. However, they trap small animals, especially insects, using modified leaves such as pitchers or snap traps. Enzymes digest the trapped animals, and the plants absorb mineral salts, especially nitrogen compounds, from them. This enables the plants to survive in nitrogen-deficient soils.
Question 10 Report
ai What is a cell?
ii name three scientists that are associated with the discovery of the cell.
b. make a diagram, 6cm to 8cm long of a plant cell and label only the organelle responsible for cell production
name one blood cell in humans that does not have the oraganelle labelled in [b]i.
iii What is the biological implication of the cell named in (b)(i) not possessing the organelle responsible for
cell reproduction?
(c) List six organelles found in a plant celI.
(a)(i) A cell is the basic structural and functional unit of life; it is the smallest unit capable of carrying out all the activities necessary for the survival of a living organism.
(a)(ii) Three scientists associated with the discovery of the cell are:
- Robert Hooke
- Anton van Leeuwenhoek
- Matthias Schleiden
(b)(i) A labelled diagram of a plant cell (drawn 6 cm to 8 cm long), with the nucleus - the organelle responsible for cell reproduction (cell division) - clearly labelled, is shown below.
The blood cell in humans that does not possess the nucleus is the red blood cell (erythrocyte). The mature mammalian red blood cell has no nucleus.
(b)(iii) Because the red blood cell has no nucleus, it lacks the DNA that controls cell division. The biological implications are:
- It cannot divide, reproduce or replace itself, so it has a short, limited lifespan (about 120 days) and must be continually replaced by new cells made in the red bone marrow.
- It cannot repair itself or synthesise new proteins and enzymes once damaged.
- The absence of the nucleus creates more internal space for haemoglobin, increasing the cell's oxygen-carrying capacity.
(c) Six organelles found in a plant cell:
- Nucleus
- Chloroplast
- Mitochondrion
- Endoplasmic reticulum
- Golgi apparatus
- Ribosome
Answer Details
(a)(i) A cell is the basic structural and functional unit of life; it is the smallest unit capable of carrying out all the activities necessary for the survival of a living organism.
(a)(ii) Three scientists associated with the discovery of the cell are:
- Robert Hooke
- Anton van Leeuwenhoek
- Matthias Schleiden
(b)(i) A labelled diagram of a plant cell (drawn 6 cm to 8 cm long), with the nucleus - the organelle responsible for cell reproduction (cell division) - clearly labelled, is shown below.
The blood cell in humans that does not possess the nucleus is the red blood cell (erythrocyte). The mature mammalian red blood cell has no nucleus.
(b)(iii) Because the red blood cell has no nucleus, it lacks the DNA that controls cell division. The biological implications are:
- It cannot divide, reproduce or replace itself, so it has a short, limited lifespan (about 120 days) and must be continually replaced by new cells made in the red bone marrow.
- It cannot repair itself or synthesise new proteins and enzymes once damaged.
- The absence of the nucleus creates more internal space for haemoglobin, increasing the cell's oxygen-carrying capacity.
(c) Six organelles found in a plant cell:
- Nucleus
- Chloroplast
- Mitochondrion
- Endoplasmic reticulum
- Golgi apparatus
- Ribosome
Question 11 Report
specimens A and C and answer question 1(a) to 1(e).
(a) Classify specimens A and C based on their life cycle.
A;.....................................................................
B;.......................................................................
(b) State four observable differences between specimens A and C.
(c) State three ways by which the damage to specimen A could have been prevented.
(d) Name the type of germination that would be observed when specimens A and C are planted.
A...........................................................
C...........................................................
(e) Place a flat side of specimen C on the tile.
provided, cut through the specimen longitudinally.
Make a drawing, 6 cm to 8 cm long of the cut surface of one half of specimen c and label fully.
specimen C and label fully.
(i) Add a drop of iodine solution to the cut surface of th other half of specimen C and record the activity on the table below
1.(a) Classification of specimens A and C according to thier lifecycle
A: Annual/perennial
C: Annual
b) Observable diferences between specimens
A and C
| A weevil-damaged bean seed | c/maize grain |
| brown,red,black,white coloured | white/yellow/cream/coloured |
| one scar present | two scars present |
| hilium present | hilium absent |
| presence of hole on the seed | absence of holes |
| kidney shaped | shield/oblong shaped |
| testa present/pericarp absent | pericarp/fruit wall present |
| has bulging body | presence of two flat sides |
| presence of micropyle | micropyle absent |
Ways by which the damage to specimen A could have been prevented
Storage in air-tight containers/vacuum seal the bean seeds/add oxygen absorber
i. Use of pesticides/fumiganting/secticide
ii. Freezing
iv. Irradiation/radiation of seeds
v.Hygienic storage on sanitation
d) Type of germination of specimens A and C when planted
A: Epigeal
C: Hypogeal
[ei]Drawing/diagram of longitudinal section
L.S.)of specimen C/maize grain
Answer Details
1.(a) Classification of specimens A and C according to thier lifecycle
A: Annual/perennial
C: Annual
b) Observable diferences between specimens
A and C
| A weevil-damaged bean seed | c/maize grain |
| brown,red,black,white coloured | white/yellow/cream/coloured |
| one scar present | two scars present |
| hilium present | hilium absent |
| presence of hole on the seed | absence of holes |
| kidney shaped | shield/oblong shaped |
| testa present/pericarp absent | pericarp/fruit wall present |
| has bulging body | presence of two flat sides |
| presence of micropyle | micropyle absent |
Ways by which the damage to specimen A could have been prevented
Storage in air-tight containers/vacuum seal the bean seeds/add oxygen absorber
i. Use of pesticides/fumiganting/secticide
ii. Freezing
iv. Irradiation/radiation of seeds
v.Hygienic storage on sanitation
d) Type of germination of specimens A and C when planted
A: Epigeal
C: Hypogeal
[ei]Drawing/diagram of longitudinal section
L.S.)of specimen C/maize grain
Question 12 Report
(a)(i) What is an ecological niche?
(i) State five roles played by a mango tree in its ecological niche.
(b)i) State two reasons why ecologists use sampling techniques in population studies.
(i) State four examples of sampling techniques used in population studies.
(c)Name four types of fingerprints in humans.
(d)) Name the plant used by Gregor Mendel in his experiment.
(ii) State two reasons why the plant named in 3(d) was used.
