Biology Questions

AIDS: The term means Acquired Immunity Deficiency Synodrome. The virus attacks the T cells of the (white corpuscle type) blood and destroys them.

A pulse can be detected most easily in Arteries as they are under much greater pressure than veins because they are carrying blood away from the heart which is the pumping machine to force blood to move to all of the body.

Every time the hear contracts, it can be felt in an artery where a surge of blood has just been forced.

A capillary is too small to feel a pulse and a lacteal is part of the lymphatic system found in the small intestine.

The floridian starch is reserve food materials in the red algae or the members of class Rhodophytae. It is a characteristic feature of this group.

Genetic drift or allelic drift is the change in the relative frequency in which a gene variant (allele) occurs in a population due to random sampling and chance.

When is genetic drift a major factor in evolution is

* When there is low gene flow.

* When there is no selective pressure.

* When there is a bottleneck.

Jean Piaget was a cognitive psychologist who identified four stages of development: the sensorimotor stage from birth to 2 years, the preoperational stage from age 2 to age 7, the concrete operational stage from age 7 to 11, and the formal operational stage from age 11 to adult. He identified milestones that occur at each stage.

According to Piaget, the main task of the sensorimotor stage is for the child to learn the concept of object permanence, use senses and motor skills to understand the world.

Prokaryotic cells lack a nucleus and do not have an extensive system of interior membranes. They are encased in a cell wall and many contain external structures such as a capsule, flagellum, or pili. Prokaryotes – have a relatively uniform interior that is not subdivided by internal membranes.