2021 WAEC Biology Practical Questions and Answers

Study Specimen A and B and answer question 1(a) to 1(c). (a) (i) Name the habitat of each of specimens A and B. (ii) Name the adult stage into which each of specimens A and B would develop. (iii) Name of the phylum and class common to the adult stage of specimens A and B. (b) State three observations features of biological significance in; (i) Specimen A; (ii) Specimen B. (c)(i) State four observable structural differences between specimens A and B. (ii) State three observable similarities between specimens A and B. (1ai) (2020 Answers) 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 WAEC Biology Practical 2021

Questions and Answers (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 (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) (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 – Observationtime(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