Biology 2022 Jamb Examination

Male agama lizards perform conspicuous displays — head-bobbing, push-ups, and bright coloration — primarily as courtship behaviours to attract females and advertise fitness. These displays also serve to establish territory, but their main reproductive function is to increase mating opportunities with receptive females.

The phenotype of an organism encompasses all observable traits — morphology, biochemical properties, behaviour and physiological characteristics — resulting from the interaction of its genotype with the environment. It contrasts with genotype, which is the genetic makeup that may or may not be expressed.

Enzymatic digestion of complex carbohydrates (starches and disaccharides) breaks them down into simple monosaccharides. Glucose is the primary final product absorbed by the small intestine and used by cells for energy production via cellular respiration or stored as glycogen.

The pentadactyl limb pattern (five-digit limb structure) appearing across diverse vertebrates indicates a common ancestral origin and subsequent modification for different functions. This homology provides strong evidence for evolution by descent with modification rather than independent creation.

Insufficient thyroxine (thyroid hormone) production during childhood disrupts normal brain and physical development, causing cretinism. Affected children show stunted growth, mental retardation, and other developmental abnormalities unless treated early with hormone replacement.

Petaloid sepals are sepals that resemble petals and therefore perform the visual role typically associated with petals: attracting pollinators. Their showy appearance increases the flower's visibility to insects, birds or other pollinating agents, thereby enhancing reproductive success.

Carolus Linnaeus developed the binomial nomenclature and hierarchical classification system (kingdom, phylum, class, order, family, genus, species). His system standardized naming and grouping of organisms based on shared characteristics, forming the foundation of modern taxonomy.

Camels are specially adapted to arid environments and can tolerate substantial dehydration without harmful effects. They conserve water through concentrated urine, reduced sweating, and physiological tolerance to body water loss, allowing survival for long periods without drinking.

Volvox is a colonial alga composed of many flagellated cells connected by thin cytoplasmic strands. The labelled part II corresponds to these cytoplasmic connections which facilitate communication and coordination among individual cells within the colony.

The diagram shows a spherical colonial organism composed of many cells arranged on the colony surface with cytoplasmic connections and coordinated flagellar movement. These features identify the organism as Volvox, a colonial green alga.