Biology 2004 Jamb Examination

The correct answer is D. Na+ and K+.

The action potential in nervous transmissions primarily involves the movement of sodium ions (Na+) and potassium ions (K+). During an action potential, Na+ ions rush into the neuron, causing depolarization, and then K+ ions exit the neuron, causing repolarization. This exchange of ions across the neuron's membrane is crucial for the propagation of electrical signals along nerves.

The anther is the part of the stamen (the male reproductive organ of a flower) that produces and releases pollen. It is usually located at the top of the filament.

C. II to III

The correct answer is D. 2 ATP molecules and alcohol.

During anaerobic fermentation (specifically alcohol fermentation), one glucose molecule is converted into ethanol (alcohol), carbon dioxide, and 2 ATP molecules. Pyruvic acid is an intermediate, but it's not the final product, and the process does not yield 38 ATP molecules or water and carbon dioxide, which are products of aerobic respiration.

The part labelled III is the hair follicle. Hair follicles are dynamic, tube-like structures in the dermis that generate hair, anchor it, and regulate its growth cycle (anagen, catagen, telogen). They are essential for skin repair (healing wounds), producing sebum, acting as sensory receptors for touch, and contributing to thermoregulation.

In the diagram, the structure labeled IV is the sweat gland. It is responsible for producing sweat, which helps regulate body temperature through evaporative cooling

The correct option is B. budding.

Explanation: Both Hydra and yeast reproduce through a process called budding. In this type of asexual reproduction, a new organism develops from an outgrowth or bud on the parent organism. The bud eventually detaches to become an independent organism.

The correct option is B. more rapid elongation of the hypocotyls than the epicotyl.

In epigeal germination, the hypocotyl (the part of the stem below the seed leaves) elongates rapidly, pushing the cotyledons above the soil surface. This is a characteristic feature of epigeal germination, as opposed to hypogeal germination, where the epicotyl (the part of the stem above the seed leaves) elongates more rapidly, leaving the cotyledons underground.

The correct option is D. is a medium for all metabolic reactions.

Explanation: Water is essential for all living cells because it acts as a medium in which various metabolic reactions occur. It facilitates the transport of nutrients and waste products, helps maintain cell structure, and participates directly in many biochemical processes.

The correct option is A. capillaries.

Explanation: The surface of an alveolus in mammals is richly supplied with capillaries. These tiny blood vessels allow for the exchange of gases (oxygen and carbon dioxide) between the air in the alveoli and the blood in the capillaries.