2020 WAEC BIOLOGY PRACTICAL QUESTIONS/ANSWERS VERIFIED EXPO

(4a)
TABULATE
– Specimen P-
– Test: 2 drops of specimen P in water
– Observation time(seconds): 3-4 seconds before it dissolves
– Medium of spread: Water
– Sense organ: Eye

-Specimen Q-
– Test: Teaspoon of specimen Q + water
– Observation time(seconds): Dissolves within 65 seconds
– Medium of spread: Water
– Sense organ: Eye

-Specimen R-
– Test: Cut section of specimen R
– Observation time(seconds): 2 seconds or almost immediately
– Medium of spread: Air
– Sense organ: Nose

(4b)
Osmosis

(4c)
(i)
– Increase in temperature
– Difference in concentration
(ii)
– Molecular size
– Increase in temperature
(iii)
– Increase in temperature
– Difference in concentration

(4di)

(4dii)
It is Whorl

(4diii)
– Loop
– Whorl
– Arch/Compound

(4div)
– Crime detections
– Identification of individuals
– Genetic variation in man

(4dv)
Discontinuous variation

=======================

(1ai)

TABULATE

– TEST: Specimen B + 2drops of iodine solution

– OBSERVATION: No precipitate is found (No reaction is occurring)

INFERENCE: It indicates specimen B contains no starch content

(1aii)
TABULATE

– TEST: Specimen B + 2ml of NaOH(aq) + 3 drops of CuSO4 + shake

– OBSERVATION: The mixture will turn to purple or violet colour

– INFERENCE: Protein is present

(1b)
(i) Test for starch
(ii) Test for protein (Biurets test)

(1c)
– Additional income is obtained through quality mushrooms
– They contain vitamins and proteins and Laos acts as antioxidants supporting the immune system

(1di)
Fungi

(1dii)
– Eukaryotic organism
– Absence of chlorophyll
– Cell walls made of chitin instead of cellulose

(1diii)
– Molds
– Mildews
– Smuts
– Rusts
– Yeast

(1ei)
Mullosca

(1eii)
– Presence of tentacles
– Possession of soft and unsegmented bodies
– Body is covered by a mantle and she’ll
– They are bilaterally symmetrical
– They are triploblastic with three layers

(1fi)
– Specimen C (mushrooms) are decomposers breaking down surface waste releasing nitrogen back into the soil in form of ammonium nitrate, a nutrient essential for plant survival

(1fii)
Saprophytic mode of nutrition
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(2a)
E: Succulent Fruit
F: Berry/Flesh Fruit
H: Legume/Pod

(2b)
E: Parietal Plancentation
F: Axile Plancentation

(2c)
E: Human
F: Animal
H: Explosive Mechanism

(2di)
Specimen E attract birds, squirrels, and other small mammals. Consumption of the fruit will lead to dispersal of the seeds in feces (by human)

(2dii)
(i)Vitamin C
(ii)Magnesium

(2ei)
Green

(2eii)
It signify that they are still young

(2fi)
Marginal placentation

(2fii)

Posted by admin on 28th August 2020.

Tags: 2021 WAEC BIOLOGY PRACTICAL QUESTIONS/ANSWERS VERIFIED EXPO, WAEC BIOLOGY PRACTICAL QUESTIONS/ANSWERS VERIFIED EXPO

Categories: WAEC