Biology 2018 Jamb Examination

Cold-blooded animals, or poikilotherms, are those whose internal body temperature varies with the temperature of the environment. They cannot internally regulate their body heat and depend on external sources, such as sunlight, to maintain optimal activity levels.

Arteries are blood vessels that carry oxygenated blood away from the heart to various tissues of the body. The aorta, as the largest artery, distributes oxygen-rich blood to systemic circulation, ensuring that all organs receive the necessary oxygen for cellular respiration.

The pancreas is a mixed gland because it has both endocrine and exocrine functions. The endocrine part secretes insulin and glucagon into the blood to regulate blood glucose, while the exocrine part produces digestive enzymes released into the small intestine.

A population refers to a group of organisms of the same species living in a defined geographical area at the same time. Populations are essential for studying ecology, as they allow understanding of reproduction rates, resource use, and interactions within a species.

Tikka disease affects groundnut crops and is caused by a fungal pathogen. It leads to leaf spots, reduced photosynthesis, and ultimately lower yield. Effective crop management and resistant varieties are essential to control this disease.

Humans can be infected at stage 2 of the depicted life cycle, which represents the infective stage of the parasite. Infection usually occurs through direct contact, ingestion, or vectors, depending on the parasite’s transmission mode, leading to disease manifestation in humans.

The total salt content in human blood is approximately 0.85 to 0.9%, mainly consisting of sodium chloride along with small amounts of potassium, calcium, and magnesium salts. This concentration is essential for maintaining osmotic balance and proper physiological functions.

The scolex is the anterior end of a tapeworm and serves as the attachment organ. It typically has suckers and hooks that enable the parasite to anchor itself to the intestinal wall of the host, ensuring it remains in place to absorb nutrients.

Lizards are cold-blooded, or poikilothermic, animals. Their body temperature fluctuates with the surrounding environment, and they rely on external heat sources, such as sunlight, to regulate their physiological activity and metabolism.

The oxidation of 1 gram of glucose releases approximately 4 kilocalories of energy. This energy is used in cellular processes such as metabolism, growth, and movement, and forms the basis for understanding caloric content in nutrition.