2021 NABTEB GCE BIOLOGY VERIFIED ANSWERS

 

2021 NABTEB GCE BIOLOGY VERIFIED ANSWERS

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(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

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Completed