Biology 2025 Jamb Examination

Niche differentiation occurs when members of the same species occupy different ecological roles at different life stages to avoid competing for the same resources. The Toad is a perfect example: the larvae (tadpoles) live in water and eat algae, while the adults live on land and eat insects. This ensures that the young and adults do not compete for food or space.

Seaweeds (multicellular algae) and Barnacles (crustaceans that attach to rocks or ships) are characteristic of Marine habitats. They are specifically adapted to survive in high-salinity environments and the physical stresses of ocean waves and tides.

Competition between individuals of different species (such as a cow and a goat) for the same limited resource (grass) is known as interspecific competition. Intraspecific competition, by contrast, occurs between members of the same species.

Oxygen is a vital component of aerobic respiration. Once transported to the cells, it is used in the mitochondria to oxidize glucose, a process that results in the release of energy from food (ATP) needed for all cellular activities.

These tiny, non-functional bones are 'vestigial structures.' Their presence provides evidence for evolution, suggesting that whales evolved from four-legged land ancestors that gradually adapted to a fully aquatic lifestyle, causing the hind limbs to shrink over millions of years.

The genotype refers to the complete set of genetic material (alleles) an organism carries, which determines its hereditary traits. In contrast, the phenotype is the physical expression or observable characteristics of those genes, such as eye color or height.

While chameleons also change color to communicate or regulate temperature, their ability to match their environment is a primary form of defence known as camouflage. By blending into the background, they remain hidden from predators like snakes and birds.

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A reflex action is an involuntary, rapid response to a stimulus that does not involve conscious thought. Sneezing is a protective reflex triggered by irritation in the nasal cavity to expel foreign particles. Walking, dancing, and crying (emotional) are voluntary or complex behaviors controlled by the brain's higher centers.

Amino acids are the building blocks of proteins. They are linked together by peptide bonds to form long chains called polypeptides, which then fold into specific three-dimensional shapes to perform various biological functions.

A Secchi disc is a plain white (or black and white) circular disk that is lowered into the water until it is no longer visible. The depth at which it disappears is used to calculate the transparency or turbidity of the water. An anemometer measures wind speed, a barometer measures pressure, and a hygrometer measures humidity.