NABTEB NOV/DEC 2021 GCE BIOLOGY PRACTICAL ANSWERS

Alternative to Biology Practical (9:00am-11:00am)

NABTEB NOV/DEC GCE BIOLOGY PRACTICAL ANSWERS 2021:

(1i)

Fertilization

(1ii)

[pick any two]

(a) The presence of hair or fur.

(b) Sweat glands.

(c) Glands specialized to produce milk, known as mammary glands.

(d) Three middle ear bones.

(1iii)

280 days or 40 weeks

(1iv)

Calyx

(1v)

[Pick any two]

(a) auxin.

(b) abscisic acid

(c) ethylene

(d) gibberellins

(e) cytokinins

(1vi)

(a) iron

(b) magnesium

(1vii)

[Pick any two]

(a) Crocodilians

(b) Snakes

(c) amphisbaenians

(d) lizards

(1viii)

When controlled by a particular allele of a gene and which will only be displayed when the individual is homozygous for this allele.

(1ix)

– O negative blood

(1x)

(a) anemometer is an instrument that measures wind speed and wind pressure.

(b) pooter is used in ecology for collection of insects.

(1xi)

[Pick any four]

(a) Mid- brain

(b) Occipital lobe

(c) Temporal lobe

(d) Parietal lobe

(e) Frontal lobe

(f) Cerebral cortex

(g) Cerebellum

(1xii)

Hemoglobin (Heme + Globin)

(1xiii)

[Pick any two]

(a) Bile production and excretion.

(b) Excretion of bilirubin, cholesterol, hormones, and drugs.

(c) Metabolism of fats, proteins, and carbohydrates.

Enzyme activation.

(d) Storage of glycogen, vitamins, and minerals.

(1xiv)

Commensalism

(1xv)

[Pick any two]

(a) grasshoppers

(b) cicadas

(c) cockroaches

(d) Lice

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(2a)

[TABULATE]

(i)

Ecological Instrument:

– Rain gauge

Ecological Factor Measured:

– Precipitating rain

(ii)

Ecological Instrument:

– Anemometers

Ecological Factor Measured:

– Wind Speed

(iii)

Ecological Instrument

– Secchi disk:

Ecological Factor Measured

– Turbidity or Transparency of water

(iv)

Ecological Instrument:

-Barometer

Ecological Factor Measured:

– Atmospheric pressure

(v)

Ecological Instrument:

– Photometer

Ecological Factor Measured:

– Strength of electromagnetic radiation

(2b)

(i) Diatoms —> Mosquito Larvae —> King fisher

(ii) Primary Producer: Diatoms

(iii) Tertiary customer: King fisher

(2c)

There is a tendency of over crowding in the ecosystem due to the fact that there is possibility of decrease in death rate as a result of tertiary consumer (king fisher) from the environment

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(3ai)

-TEST: To a piece of yam iodine solution was added

-OBSERVATION: The colour will change to blue black

-INFERENCE: Starch is present

(3aii)

-TEST: To a small quantity maltose in a test tube was added Benedict solution , the mixture was boiled for 4-6 minutes

-OBSERVATION: A brick red precipitate is seen

-INTERFERENCE: Glucose is present

(3aiii)

-TEST: To small quantity of egg white was added 3cm³ of million regent , the mixture was warmed in a water bath for few minutes

-OBSERVATION: A red precipitate would appear

-INTERFERENCE: Protein is present

(3aiv)

-TEST: A few drops of Sudan (III) was added to oil in a test tube and then boiled

-OBSERVATION: A red coloration appeared before boiling. A black precipitate was observed on boiling

-INTERFERENCE: Fat & Oil is present

(3b)

(i) Starch — yam, rice

(ii) Lipid — palm oil , groundnut

(iii) Protein — Milk , cheese

(iv) Vitamins — Soya beans , palm wine

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(4a)

(i) Anterior Contractile Vacuole

(ii) Cilium

(iii) Meganucleus

(iv) Micronucleus

(v) Gullet

(vi) Food vacuole

(vii) Posterior Contractile Vacuole

(4bi)

Paramecium

(4bii)

Aquatic habitats

(4biii)

Protozoa

(4biv)

-Amoeba

-Plasmoduim

(4c)

(ii) Cilium: It serves as locomotion through surrounding of water

(v) Gullet: It is responsible for ingestion of food

(iii) Posterior Contractile Vacuole: Gets rid of excess water