Biology

People with blood type O negative (O-) lack A, B, and Rh antigens, making their blood compatible with all other blood types, so they are called universal donors.

The scientific name of humans is Homo sapiens, which is the accepted binomial nomenclature in biological classification.

Dead red blood cells are primarily removed and stored in the spleen, which acts as a blood filter and recycles old or damaged red blood cells.

Animals that live in trees, including tree trunks, are called arboreal because 'arboreal' refers to tree-dwelling organisms. The other options refer to animals that fly (volant), live both in water and on land (amphibious), or live in water (aquatic).

Tetanus is caused by the bacterium Clostridium tetani, which produces a toxin leading to the disease. The other options are incorrect as tetanus is not caused by a virus, bacteriophage, or Salmonella.

The snake is widely recognized as a symbol of medicine, notably represented in the Rod of Asclepius, which features a serpent entwined around a staff and is associated with healing and medical practice.

The ability of the eye to see in the dark is due to rhodopsin, a purple pigment found in the rod cells of the retina that is sensitive to low light levels. Retinene is related but not the pigment responsible for night vision.

The uvula is a small fleshy extension at the back of the soft palate, hanging above the throat. It is part of the oral cavity and plays a role in speech and swallowing, confirming that it is located in the throat area.

The maxilla bones are the upper jaw bones in the human skull, forming the upper jaw and holding the upper teeth in place. Therefore, they are found in the jaw.

Hummingbirds are unique among birds because they can fly backwards due to their specialized wing structure and rapid wing beats, which allow them to hover and maneuver precisely.