2021 NABTEB GCE BIOLOGY VERIFIED ANSWERS

(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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*SECTION B*

(2ai)
– TEST
(ai) To a piece of yam iodine solution was added

– OBSERVATION
(ai) The colour will change to blue black

– INFERENCE
(ai) Starch is present

(2aii)
– TEST
(aii) To a small quantity maltose in a test tube was added Benedict solution , the mixture was boiled for 4-6 minutes

– OBSERVATION
(aii) A brick red precipitate is seen

– INTERFERENCE
(aii) Glucose is present

(2aiii)
-TEST
(aiii) To small quantity of egg white was added 3cm³ of million regent , the mixture was warmed in a water bath for few minutes

– OBSERVATION
(aiii) A red precipitate would appear

– INTERFERENCE
(aiii) Protein is present

(2aiv)
– TEST
(aiv) A few drops of Sudan (III) was added to oil in a test tube and then boiled

– OBSERVATION
(aiv) A red coloration appeared before boiling. A black precipitate was observed on boiling

– INTERFERENCE
(aiv) Fat & Oil is present

(2b)
(i) Starch — yam, rice
(ii) Lipid — palm oil , groundnut
(iii) Protein — Milk , cheese
(iv) Vitamins — Soya beans , palm wine

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(3a)
(i): Contractile Vacuole
(ii): Cilium
(iii): Maganucleus
(iv): Micronucleus
(v): Oral grove
(vi): Anal pore
(vii): Contractile Vacuole

(3b)
– Paramecium

(3bi)
– Aquatic habitats

(3bii)
– it is formed or have aquatic environment usually in straight warm water

(3biii)
-Protozoa

(3biv)
– Amoeba
-Plasmoduim

(3c)
(i) Oral grove : helps to direct food to the mouth..

(ii) Anal pore : where waste is ejected after the nutrients from food have been absorbed into

(iii) Contractile Vacuole: gets rid of excess water

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(4a)
[TABULATE]

(i)
Ecological Instrument
– Rain gauge

Ecological Factor Measured
– Precipitating rain

(ii)
Ecological Instrument
– Anemometers

Ecological Factor Measured
– Wind Speed

(iii)
Ecological Instrument
– Nephelometric Turbidity Units

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

(4b)
(i) Diatoms —> Mosquito Larvae —> King fisher

(ii) Diatoms = Producer
(iii) Tertiary customer (King fisher)

(4c)
— They 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