Diversity of Life and Microbiology MCQs for MDCAT

Correct answer: A. Community

A community is the assemblage of populations of different species (plants and animals) living together in the same habitat.

Correct answer: B. Chitin

Chitin, a nitrogen-containing polysaccharide, is the structural component of fungal cell walls, unlike the cellulose of plant cell walls.

Correct answer: A. Flagella

Many bacteria achieve motility through flagella, whip-like appendages that rotate to propel the cell.

Correct answer: C. Ascaris lumbriocoides

Ascaris lumbricoides is a common nematode parasite found in the intestines of both humans and pigs.

Correct answer: C. Mutualism

Mutualism is a symbiotic relationship between two species of organisms in which both partners benefit from the association.

Correct answer: C. Cytochrome' c'

For instance, cytochrome c, a respiratory protein is found in all aerobic species.

Correct answer: D. South American mainland

The animals species on the Galapagos islands resemble species living on the South American mainland. This is because the Galapagos islands are located about 600 miles off the coast of Ecuador in South America. The islands were formed by volcanic activity, and over time, various animal species migrated to the islands from the mainland.

Correct answer: B. Parasitic nutrition

Feeding by living in or on another organism (host) belonging to a different species is called **parasitic nutrition** (Option B). Parasites obtain nutrients from their host organism, often causing harm or damage to the host in the process.

Correct answer: C. Trout Fish

Trout fish belong to the phylum Chordata, which is characterized by animals that possess a notochord at some stage of development, a dorsal nerve cord, pharyngeal slits, and a post-anal tail. Trout specifically belong to the class Actinopterygii (ray-finned fishes) and the order Salmoniformes. They are typically found in freshwater habitats like rivers and lakes and are known for their streamlined bodies and gills for respiration. Trout are popular among anglers and play a significant role in freshwater ecosystems as both predators and prey.

Correct answer: A. Excretion

Option A is correct.The green glands found in arthropods are concerned with excretion. Green glands are paired excretory organs that are found in the head of crustaceans. They are responsible for filtering waste products from the blood and excreting them from the body. Green glands are also thought to play a role in osmoregulation, the process of maintaining a balance of water and salts in the body. The other options are not functions of the green glands:Respiration is the process of exchanging oxygen and carbon dioxide between the body and the environment. Arthropods respire through a variety of structures, including gills, tracheae, and book lungs. Digestion is the process of breaking down food into smaller molecules that can be absorbed by the body. Arthropods digest food in a variety of ways, including through their mouths, stomachs, and intestines.Circulation is the movement of blood throughout the body. Arthropods have an open circulatory system, in which the blood does not flow in closed vessels.

Correct answer: D. Monotrichous

A bacterium with a single polar flagellum is classified as Monotrichous. This means that the flagellum is located at one end (pole) of the bacterial cell.

Correct answer: C. Coelantrata

Alternation of generations is a life cycle characteristic of the phylum Cnidaria, which includes Jellyfish,Corals,Sea anemones,Hydra