2021 - JAMB Biology Past Questions & Answers - page 1

1

One of the functions of the xylem is?

A

strengthening the stem

B

manufacturing food

C

reducing loss of water

D

conducting manufactured food

CORRECT OPTION: a

Vascular tissue is comprised of the xylem and the phloem, the main transport systems of plants.

xylem, plant vascular tissue that conveys water and dissolved minerals from the roots to the rest of the plant and also provides physical support.

2

Which of the statements below is not characteristic of wind-pollinated flowers?

A

Stigmas are usually large and feathery

B

Nectary is usually absent

C

The pollen grains have rough spiny surfaces

D

The flowers are not scented.

CORRECT OPTION: c

Wind-pollinated flowers:

  • No bright colors, special odors, or nectar.
  • Small.
  • Most have no petals.
  • Stamens and stigmas exposed to air currents.
  • Large amount of pollen.
  • Pollen smooth, light, easily airborne.
  • Stigma feathery to catch pollen from wind.
3
Some of the features of an animal are scales, teeth, nares, and backbone. The animal is likely to be a?
A

toad

B

bird

C

lizard

D

rat

CORRECT OPTION: c
  •  cold-blooded ness;
  • The teeth of reptiles are also less specialized in function than are mammalian teeth.
  • a dry skin with scales but not feathers (a characteristic of birds) or hair (a characteristic of mammals);

NB: Birds do not have teeth, although they may have ridges on their bills that help them grip food.

       Birds swallow their food whole, and their gizzard (a muscular part of their stomach) grinds up the food so they can digest it.

4

Choose the sequence which represents the correct order of organisms in a food chain

A

Grass, snake, toad, grasshopper, hawk

B

Grass, grasshopper, toad, snake, hawk

C

Grass, grasshopper, snake, toad, hawk.

D

Grass, snake, grasshopper, toad, hawk

CORRECT OPTION: b

The functional group in a food chain include:

Primary producer → Primary consumer → Secondary consumer

Grass, grasshopper, toad, snake, hawk

5

Flatworms and roundworms are said to be invertebrates because?
A

they are small animals

B

they can live inside the vertebrates

C

some of them are unicellular

D

they have no backbones

CORRECT OPTION: d

- The most familiar invertebrates include the Protozoa, Porifera, Coelenterata, Platyhelminthes, Nematoda, Annelida, Echinodermata, Mollusca and Arthropoda.

- Invertebrates are animals that neither possess nor develop a vertebral column, derived from the notochord.

6

When a Spirogyra cell is immersed in a salt solution more concentrated than its cell sap, it?

A

remains unchanged

B

takes tip water and burst

C

absorbs a little water

D

loses water and shrivels

CORRECT OPTION: d

Exosmosis is the movement of water outside the cells when a cell is placed in a hypertonic solution.

The cell becomes flaccid by the movement of water outside.

7

Which of the following is NOT regarded as a pollutant on land or in the air?

A

Smoke

B

Nitrogen

C

Noise

D

Sulphur dioxide

CORRECT OPTION: b

Air Pollutants

  • Carbon Monoxide.
  • Lead.
  • Nitrogen Oxides.
  • Ozone.
  • Particulate Matter.
  • Sulfur Dioxide.
  • Other Air Pollutants.

The primary pollutants of concern in land and soil are heavy metals, such as lead, mercury and others, pesticides and other persistent organic pollutants, and pharmaceuticals, such as antibiotics used for livestock management.

Nitrogen (N), nonmetallic element of Group 15 [Va] of the periodic table.

It is a colourless, odourless, tasteless gas that is the most plentiful element in Earth's atmosphere and is a constituent of all living matter.

8
The initial volume of water poured into a bag of dry soil was 50ml and the amount that drained through was 35mI. The percentage water content of the fully soaked soil is therefore?
A

46.7

B

25.0

C

20.0

D

30.0

CORRECT OPTION: d

Percentage of water content (retained) = \(\frac{Water absorbed}{Weight of soil} * 100\) 

→ \(\frac{50 - 35}{50} * 100\)

= 30%

9

When the original king and queen of termites die, they are replaced by 

A

the king and queen of another colony

B

some adult reproductives from the same colony

C

some adult workers which are specially fed to breed

D

developing nymphs nurtured as secondary reproductives

CORRECT OPTION: d

When the queen dies, production of the blocking pheromone stops, and secondary reproductives may be produced.

In the Reticulitermes species, the queen and king may be replaced by numerous secondary reproductives, and the colony may become very large with the added productivity of many queens.

10
In demonstrating the importance of mineral elements in plants, the culture bottle must be darkened to?
A

prevent algal growth in culture solution

B

allow root growth

C

prevent breakdown of mineral elements

D

prevents photosynthesis in the root

CORRECT OPTION: a

Always use a completely opaque water storage tank - Algae uses photosynthesis to reproduce 

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