Chapter 2

Question 1

Chromosome

Answer 1

One of 46 molecules of DNA that almost every cell of the human body contains, which has all the genes. Other species have fewer chromosomes

Question 2

Zygote

Answer 2

The single cell that is formed from the fusing of two gametes, a sperm and an ovum

Question 3

Gamete

Answer 3

Reproductive cell. Sperm or an I understand that can produce a new individual if it combines with a genre from the other sex

Question 4

Allele

Answer 4

Any of the possible forms of a gene. Genes with various alleles are called polymorphic

Question 5

Phenotype

Answer 5

Observable characteristics of a person

Question 6

Dizygotic twins

Answer 6

Twins who are formed when two separate ova are fertilized by to separate sperm at roughly the same time

Question 7

Germinal period

Answer 7

First two weeks of development after conception, characterized by rapid cell division and the beginning of cell differentiation

Question 8

Fetal period

Answer 8

Stage of prenatal development from nine weeks after conception until birth, during which the fetus grows in size and matures in functioning

Question 9

Age of viability

Answer 9

The age (about 22 weeks) at which a fetus may survive outside the mothers uterus if specialized medical care is available