2023 - JAMB Biology Past Questions and Answers - page 1

The most inclusive level of classification in the Linnaean system is the Kingdom. The hierarchy, from broadest to most specific, is Kingdom, Phylum, Class, Order, Family, Genus, and Species.

Vegetative propagation is a method of asexual reproduction in plants. In this process, new individuals are produced from the vegetative parts of a single parent plant, such as stems, roots, or leaves, without the involvement of seeds or spores.

The primary organ involved in gas exchange during respiration in humans is the Lungs. The lungs contain tiny air sacs called alveoli where the exchange of oxygen and carbon dioxide occurs.

The heart is a muscular organ that contracts to circulate blood throughout the body. It is responsible for pumping blood, which carries oxygen and nutrients, to various parts of the body and returning deoxygenated blood to the lungs for oxygenation.

The characteristic typical of the phylum Arthropoda is the presence of a segmented body. Arthropods, including insects, spiders, crustaceans, and myriapods, have bodies divided into distinct segments with jointed appendages.

Nitrogen fixation is the process in the nutrient cycle that converts atmospheric nitrogen into a form that plants can utilize. This conversion is typically done by nitrogen-fixing bacteria, which convert atmospheric nitrogen gas into ammonia or related compounds.

Fishes do not sink in water primarily due to the presence of a swim bladder (option I) or air bladder (option II). These structures help control the fish's buoyancy in the water. Air sacs (option III) and air in spongy bones (option IV) are not typically associated with buoyancy control in fishes.

Steppe grasslands are regions with vast expanses of grasses and herbs but are largely devoid of trees.

The climate in steppe regions often features hot summers with temperatures that can reach or exceed 40 °C (104 °F) and winters that are relatively warm compared to other cold climates but can still experience temperatures below freezing.

This combination of temperature extremes and the absence of significant tree cover aligns with the description provided in the question.

The inheritance of traits from parents to offspring is described by Genetics. Genetics is the branch of biology that studies how traits are passed from parents to their offspring through genes.

The correct identification of excretory organs in animals is Lungs, kidneys, and skin. These organs play a role in eliminating waste products from the body.