Biology 2017 Jamb Examination

Eye color is an example of morphological variation because it involves a visible structural characteristic of an individual. Morphological variations are those differences in the physical traits, shape, size, or appearance of organisms within a species.

The cell membrane is composed primarily of a lipid bilayer interspersed with proteins. Lipids provide structural integrity and fluidity, while proteins serve as channels, receptors, and enzymes, facilitating selective transport and communication between cells and their environment.

A food chain represents the linear sequence of organisms through which energy and nutrients flow in a community. Each organism feeds on the preceding one, demonstrating the dependency of consumers on producers and other consumers in an ecosystem.

Nitrogen gas is released naturally into the atmosphere during lightning strikes, which convert atmospheric nitrogen into compounds like nitrates. This process, part of the nitrogen cycle, replenishes the nitrogen available for plant and microbial use, supporting ecosystem productivity.

These traits are morphological variations because they refer to the structural or physical differences among individuals. Morphological variations are observable and measurable features like size, shape, color, and unique patterns such as fingerprints, contributing to diversity within a species.

Savannas are grassland ecosystems with scattered trees, large herbivores, and periodic fires. The vegetation and animal life are adapted to dry and wet seasons, making them distinct from dense tropical forests, montane forests, or arid deserts.

Red blood cells, or erythrocytes, are specialized cells responsible for transporting oxygen from the lungs to tissues and carrying carbon dioxide back. Their biconcave shape increases surface area, facilitating efficient gas exchange and oxygen delivery throughout the body.

The joint between the femur and tibia is a hinge joint, allowing movement primarily in one plane, such as flexion and extension. This structural adaptation provides stability and support for locomotion while bearing body weight efficiently.

Cofactors are non-protein chemical compounds, such as metal ions or organic molecules, that assist enzymes in catalyzing reactions. They may help stabilize enzyme structure, participate in reactions, or bind substrates, enhancing enzyme efficiency and activity.

The diagram shows an anemometer, which is an instrument used to measure wind speed. Anemometers are critical in meteorology and environmental studies, helping monitor weather conditions, assess energy potential for wind turbines, and study climate patterns.