WAEC GCE 2020 - BIOLOGY ANSWER

BIOLOGY OBJ

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(2a)
Carbon(iv)oxide + water --> Glucose + Oxygen

(2b)
(i)6
(ii)6
(iii)1
(iv)6

(2c)
(i)Plants
(ii)Chloroplast

(2d)
- Green plants use this process to make food from sunlight, Carbon(iv)oxide and water in the atmosphere.
- It is their primary source of food

(2e)
(i)Sunlight - sunlight induces the first step in this process
(ii)Chlorophyll - it is responsible for giving the plant its green colour

(2f)
- Autotrophic mode of nutrition
- Heterotrophic mode of nutrition
- Holozoic mode of nutrition

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(3a)
TABULATE

BIOLOGY ASSOCIATION || EXAMPLE
Commensalism - Sharks and remora fish, Tigers and golden jackals

Mutualism - Bees and flowers, humans and bacteria in the gut

Parasitism - Humans and tapeworms, cows and ticks

Neutralism - Rainbow trout, and dandevon cactus and tarantulas

(3b)
Pollution can referred to as the introduction of harmful materials or substances into our environment thereby causing adverse charges.

(3ci)
(i)It contributes to global warming
(ii)It leaves a huge carbon footprints

(3cii)
(i)it also contributes to global climate change
(ii)It emits mercury which is a neurotoxin as well as carbon dioxide

(3ciii)
(i)When it spills in aquatic bodies, it causes loss of aquatic lives
(ii)On land, crude oil spills reduce food productivity


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(6a)
(i) Dominance refers to the exertion of a major controlling influence of one or more species upon all other species by virtue of their number, size, productivity or related activities.

(ii) Size: Population size is the number of individual organisms in a population.

(iii) Density: This the number of living organisms per unit area or volume.

(6b)
(i) Frog has lungs for breathing but also breathes through its skin.
(ii) They have webbed feet, which help them to swim
(iii) They have long and strong hind limbs, which help them in leaping and catching their prey.

(6c)
(i) This is a mismatched blood transfusion. The blood will agglutinate which will lead to fatality. In such a situation, a reaction known as hemolytic transfusion reaction causes the patient's body to form antibodies that attack the new blood cells.

(ii) The patient' blood is tested and to get a matched to be transfused.

(iii) Discontinuous variation

(iv) To know the patient's rhesus factor and blood group which are parameters necessary for a successful blood transfusion

(6di)
(i) Bacteria
(ii) Plants
(iii) Animals

(6dii)
(i) Nitrosomoners
(ii) Nitrobacta
(iii) Fungi

(6e)
(i) Cook the food well
(ii) Always cover the food
(iii) Ensure the environment is always clean

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