2014 WASSCE – BIOLOGY 2 SOLUTION
(a)(i) Characteristic of Living organisms:
- Movement/locomotion
- Excretion
- Respiration
- Reproduction
- Irritability/sensitivity/response
- Growth/development
- Nutrition/feeding
- Competition
- Adaptation
- Life span/death
(ii) Movement: Living things change the position of the whole body/parts of the body; from one place to
another; in search of food/shelter/mates, etc.
Excretion: This involves the removal/getting rid of waste products of cell metabolism; membole wastes are
poisonous if allowed to accumulate.
Respiration This is the breakdown/burning of food substances; by aerobic/anaerobic respiration; to release
energy needed for all processes of life.
Reproduction: This is the ability of living organisms to produce new individuals of their own kind; this
ensures the continuity of the species of an organism.
Irritability: Response/ reaction of organisms; towards changes in the environment; to ensure survival.
Nutrition: the process involved in obtaining/manufacturing food; can be autotrophic/heterotrophic; and
utilizing it for growth and maintenance/life processes.
Growth: This is the irreversible increase; in size and weight of an organism; which leads to complexity and
maturation.
Competition: Ability of organisms to struggle; for all necessity of life; to survive in their environment.
Adaptation: Ability of organisms to adjust; to changes in environment; for survival.
Life span/death: All living organisms have definite period of existence; all organisms die.
b Differences between plants and animals;
Animals plants
move from place to place, locomotion, move Are fixed/do not move from place to place, and move only
with the whole body parts of the body, root/stem/leaf
Heterotrophic mode of nutrition that depend on Autotrophic mode of nutrition/ manufacture their own food
already-made food using the energy from the sun
No chlorophyll/chloroplast chlorophyll/chloroplast present
No cell wall Has a cell wall made of cellulose
sense organs present sense organs absent
Growth is limited/definite, growth in all parts
growth is unlimited/indefinite .growth is apical or terminal
of the body
stores carbohydrates as glycogen stores carbohydrates as starch
Has special excretory body No special excretory body
Response is fast, short termed response very slow/short termed
Respiratory organs present No respiratory organs
(c)(i) Name of organism:
Euglena/Chlamydomonas.
(ii) Animal features: For Euglena
— Gullet for feeding.
— Has flagellum for locomotion in water.
— Myonemes for movement.
— Has pellicle that gives it a definite shape.
— Has eye spot to detect light intensity.
— Has contractile vacuole for osmoregulation and excretion.
Plant features:
- Definite shape.
— Has chioroplasts containing chlorophyll used to absorb light.
— Paramylum granules.
— Pyrenoid.
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(a) Definition of terms:
(i) Elimination: Removal of undigested food; from the body of living organisms.
(ii) Excretion: Removal of waste products of metabolism; from the cells/tissues of an organism; may be toxic
if retained in the body.
(iii) Secretion: Production and release of substances; useful to the body; by specialized glands of living
organism.
(b) Digestion of boiled fish in the gut of humans: Boiled fish is a source of protein; chewed and swallowed
into the stomach; digestion of protein starts from the stomach; stomach secrets gastric juice; containing
pepsin, rennin and hydrochloric acid; pepsin in acidic medium acts on the boiled fish and convert it to
peptides; peptides move into the duodenum/small intestine; into which pancreatic juice is secreted;
undigested protein is acted upon by trypsin in alkaline medium; into peptides/peptones, erepsin finally acts
on peptides/peptones in alkaline medium; and converts it into amino acids.
(c) Diagram of villus
Title TL: - Longitudinal section of villus. Size: (8 — 10cm long).
Quality (Q): Clarity of lines. Neatness of labels.
Details: Epithelium layer shown (EL) Conical shape of villus (one cell thick) (CV).
Labels (L): Epithelium layer blood capillary, lacteal, lymphatic vessels, goblet cells, venule, arteriols, cryps of
lieberkuhn, cells of paneth, muscularis mucosa.
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(a)(i) Biosphere: Total/whole area, part of the earth/lithosphere/ hydrosphere/water, and atmosphere/air,
inhabitable by living things/where life exists.
(ii) Habitat: A place/home; within an environment, where an organism naturally lives/dwells.
(b) Mode of nutrition of named carnivorous plants:
• - Carnivorous plants have green leaves and are able to manufacture their own food carry out
photosynthesis.
• They have roots to absorb water and mineral salts from the soil.
• Usually grow in places with little nitrogenous salts.
• Use insects/other small animals as source of Nitrogen.
• They have devices/modified leaves with bright colour/sents/sugary liquids/stcky wet surfaces for
attracting and trapping insects.
• Once the insects is trapped, the plant secretes enzymes to kill and digest it.
• The soluble nitrogenous compounds are absorbed/assimilated by the plant.
Name of carnivourous plants: -
• Butterwort/Pinquicula
• Bladderwort/ Utricularia
• Sundew/Drosera
• Venus fly-trap/Dionaea
• Pitcher plants/Nepenthes/Sarracenta.
(c) Importance of fruits and seed dispersal: -
• Prevents overcrowding of plants.
• Prevents undersirable competition for space/light/water and nutrients.
• Prevents diseases from spreading among plant species.
• Results in colonization of new areas with new plants.
• Results in adaptation to adverse/harsh/unsuitable environment.
(d) Soil conservation method: -
• Contour ploughing/ridges are made along the contour of a slopping land/to prevent water running
down the hill/slope/and washing away soil.
• Strip cultivation/the land is divided into strips along the contours of the slopes/crops are planted in
rows that alternate with the strips planted with cover crops/grasses.
• Terracing/constriction of terraces which create barriers to hinder rapid water flow down the slope.
• Mulching/materials left after weeding or harvest are left to lie on the soil/ protecting the soil against
agents of erosion.
• Afforestation/cover cropping/growing grasses, trees and shrubs to cover and protect the soil.
• Crop rotation/growing crops on a piece of land in sequence/season after season to maintain its fertility.
• Storm drains/construction of barriers/to stop free-flow of surface water through farms.
• Application of manure/fertilizer/to stabilize the soil.
• Avoid bush burning.
• Avoid over grazing.
(a)(i) Co-dominance: Co-dominance occurs when both the alleles in an heterozygous individual are fully
expressed; that is both alleles exert their effects so that the hybrid has a phenotype; that is different from what
the parents exhibit.
(ii) Calculation of individuals with co-dominant blood group: Mention of co-dominant blood group is AB.
Evidence of calculation 32.8% of 250 OR 32.8/100 x 250 = 82 individuals/ people.
(iii) Total number of individuals that can donate blood to blood group B: The total number of individuals
will be from groups B and 0.
—14% of the population is Blood group B 14% of 250 OR 14/100 x 250 = 35 individuals/people.
— 45.2% of the population is Blood group 0 45.2% of 250 OR 45.2/100 x 250 = 113 individuals/people.
— Total number of people = 113 of group 0+ 35 of group B = 148 Individuals/people can donate blood to the
accident victim in B. OR The total number of individuals from (B and 0) blood group B and 0
— 14% + 45.2 = 59.2%.
— 59.2% of 250. 592/100 x 250 = 148 people/individuals.
(b)
(a) Reasons why animals move from place to place:
(i) To search for food.
(ii) Escape predators.
(iii) Find mates for reproduction.
(iv) To disperse/reduce competition/overcrowding by moving to new locations.
(v) Avoid dangers. (vi) Find new and favourable habitats.
(b) Function of structures found in plant:
(i) Epidermis: For protection of inner cells from injury, infection, prevent excessive loss of water.
(ii) Phloem: Responsible for the transportation of enzymes/hormones; manufactured food.
(iii) Sclerenchyma: Strengthens the stem/provide mechanical support; makes plants flexible.
(c) Examples of organism:
(i) Parasitic plants: Viscum/mistletoe; dodder plant/Cassytha; Cuscuta; phytophisor; peronospora.
(ii) Saprophyta: Bacteria; fungi/Rhizopus; Mucor, Aspergillus; Mushroom/Agaricus.
(d) adaptive features of plants in salt water swamps: -
• Succulent stem/root/store water; to dilute the salt.
• Presence of pneumatophores/breathing roots; for breathing atmosphere air/oxygen.
• Presence of stilt roots; for anchorage.
• Viviparous seedling; to ensure their survival/continuity.
• Some a secrete excess salt into swamps; to maintain balance of body salt.
(e) Factors that:
(i) Increase population density:
• Increased birth rate/natality
• immigration, increase a food availability
• low mortality rate.
(ii) Decrease population density:
• Emigration
• diseases
• drought/famine/natural disaster
• high mortality rate
• low natality rate.
(f) Ways modern agricultural activities may threaten the survival of species: -
• Deforestation/commercial farming destroys habitats of species.
• Destruction/loss of natural vegetation/habitat.
• Over hunting of games reduces population of species.
• Improper/Indiscriminate application of chemical/salinizationteutrophication, pesticides destroys
species.
• Lack of afforestation practices.
• Inappropriate fishing methods threaten the population of fish.
(g) Reasons why mitosis is important to living organisms: -
• It ensures growth.
• Involved asexual ,reproduction e.g. fission, budding, spore formation.
• Ensures retention of diploid condition. Repair of tissues within organisms.
• Transfer of exact genetic code from parents to offspring.
(h) Causes of food spoilage: -
• Microbial attacks by bacteria or fungi/or saprophytic action.
• Pest attack by beetles, weevils that destroy stored grains.
• Improper storage which results in deterioration and spoilage of stored foods.
• Destruction of stored fruits and meat by some worms, usually larva of flies.
• Delay in transportation due to bad roads.
• Lack of market facilities for the commodity.
• Poor harvesting method/damage to fruits/ vegetables/tubers during harvesting.
• Poor unhygienic handling/processing/exposure to dust.
• Storage in contaminated containers.
• Use of contaminated water to wash food.
