The genetic difference between individuals

How many sperm does it need to fertilize an egg?

Long strings of genetic materials known as deoxyribonucleic acid

It is a helix-shaped molecule made up of nucleotide base pairs.

How many chromosomes does an egg and sperm contains?

The actual carrier of hereditary traits that control or partially control a number of visible characteristics, known as traits, such as eye color, hair color, and so on.

a specific version of a gene.

A person's ________ is the genetic makeup of that individual.

refers to the individual's inherited physical characteristics, which are a combination of genetic and environmental influences.

When someone has two copies of the same allele, they are said to be ________ for that allele.

When someone has a combination of alleles for a given gene, they are said to be __________.

Two types of allele

a tool used to predict how genes will interact in the production of offspring.

Developmental psychologists seek to learn the causes of ________

Prenatal Stage: Week 1-2

Prenatal Stage: week 3-8

Prenatal Stage: week 9-40

occurs when sperm fertilizes an egg and forms a zygote

begins as a one-cell structure that is created when a sperm and egg merge. The genetic makeup and sex of the baby are set at this point.

It is a fragile process, and fewer than one-half, of all zygotes survive beyond the first two weeks.