Biology

Cockroaches belong to the class Insecta, which typically have three pairs of walking legs. Therefore, a cockroach has three pairs of walking legs.

Muscles, tissues, and blood are primarily composed of proteins, which are essential for their structure and function. Carbohydrates, vitamins, and fats play other roles but are not the main building blocks of these body components.

Insulin is the hormone that regulates the metabolism of sugar by facilitating the uptake of glucose into cells and maintaining blood sugar levels. Thyroid hormones influence metabolism broadly but do not specifically regulate sugar metabolism. Glucose is the sugar itself, not a regulator.

Fish respire through their gills, which extract oxygen from water. They do not use lungs or fins for respiration, and the nose is not involved in breathing.

Human bone contains calcium, boron, and phosphate as part of its mineral and organic matrix. However, chondroitin sulfate is primarily found in cartilage, not bone, making it the correct answer for what human bone does not contain.

Ecology is the branch of biology that studies organisms and their interactions with each other and their environment. Acoustics relates to sound, Ichthyology is the study of fish, and 'None of these' is incorrect.

Fishes primarily excrete nitrogenous waste in the form of ammonia, which is highly soluble in water and can be easily eliminated through their gills and urine. This is typical for aquatic animals that live in water-rich environments.

Theophrastus is widely regarded as the Father of Botany because he was the first to systematically study and write about plants and their classification. His works laid the foundation for the science of botany.

Dolphins use both sight and sound to perceive their environment. They have good vision underwater and rely heavily on echolocation (sound) to navigate and find prey.

The hypothalamus is the part of the brain responsible for regulating body temperature by maintaining homeostasis through various mechanisms such as sweating and shivering.