2022 - JAMB Biology Past Questions and Answers - page 3

The correct answer is Option C

Cnidarians and flatworms, which are simple organisms, have every cell in their body located near the external environment

Their cells are kept moist, and direct diffusion allows gases to spread out quickly. Flatworms are tiny, flat worms that "breathe" literally by diffusing fluid across their outer membrane.

Annelids possess a closed circulatory system where blood remains entirely contained in vessels.

Although many species of annelids have simple gills, they do not have lungs.

The correct answer is Option C

Chromosomal regions known as centromeres play a crucial role in mediating the assembly of kinetochores and attachment to the spindle during cell division.

The correct answer is Option B

If both X chromosomes of a woman have the nonworking gene, she will be colorblind.

As sons inherit their only X chromosome from their mother, the chances are high that they will also be colorblind.

The correct answer is Option B

Blood is carried away from the heart through arteries, which branch into smaller vessels called arterioles.

Arterioles then distribute blood to capillary beds, where exchange of substances occurs with the body tissues. The capillaries lead back to venules, which are small vessels that flow into larger veins and eventually transport the blood back to the heart. Veins, in turn, are responsible for carrying the blood back to the heart.

The correct answer is Option C

The trees of temperate woods and those of rainforests are very different. Trees in the rainforest can reach enormous sizes and are stabilised in the shallow forest soils by strong, strut-like buttresses at the base of the trunk. Huge creepers wrap themselves in a web around tree trunks.

The correct answer is Option D

Meiosis generates new combinations of genetic material in each of its four daughter cells by exchanging DNA between paired chromosomes. The exchange of DNA creates a wide range of genetic variation, resulting in the production of gametes that exhibit incredible diversity.

The correct answer is Option A

If both partners have the AS genotype, they should not marry as their children may inherit the sickle cell anemia gene and have the SS genotype, or they may inherit the AS or AA genotype.

When an individual with the AA genotype marries someone with the AS genotype, their offspring can have either AA or AS genotypes, which is considered favorable.

The correct answer is Option B

A wind vane is usually used to measure the wind's direction.

The correct answer is Option D

Most fungi are saprophytic, including bread mould.

Saprophytic organisms are those that eat decayed or dead things.

The correct answer is Option B

Plants absorb atmospheric CO2 as photosynthetic organisms, chemically lowering the carbon.

In addition to providing the carbon skeletons for the organic molecules that make up a plant's structure, this signifies the acquisition of chemical energy that can be stored by the plant.