A) The polar body is the egg cell which is then fertilized by the sperm cell. B) Far fewer eggs are produced by the female than sperm produced by the male. C) Meiosis I begins in the female fetus. D) Meiosis II is not completed until after the egg cell makes contact with the sperm cell.
What he was more interested in was the way in which fundamental concepts like the very idea of number, time, quantity, causality, justice and so on emerged. Piaget (1936) was the first psychologist to make a systematic study of cognitive development. His contributions include a stage theory of child cognitive development, detailed observational studies of cognition in children, and a series of simple but ingenious tests to reveal different cognitive abilities.
B.F. Skinner. Skinner was one of the most influential psychologists of the 20th century. He founded the school of thought known as radical behaviorism, which built on and expanded the theory of behaviorism.