Sexual Reproduction and Meiosis (11.1)

sexual reproduction

type of reproduction in which the genetic material from two different cells combine producing an offspring

egg

Female sex cell

sperm

Male sex cell

Fertilization

an egg cell and a sperm cell join together

zygote

fertilized egg

gametes

sex cells

body cells

Any cells in the body other than reproductive cells

diploid

cells that have pairs of chromosomes

haploid

cells that have only one chromosome from each pair

meiosis

one diploid cell divides and makes four haploid sex cells

homologous chromosomes

Pair of chromosomes that have genes for the same traits arranged in the same order

Interphase

stage where chromosomes are copied

prophase I

Crossing over occurs

metaphase I

Paired homologous chromosomes line up across the center of the cell

anaphase I

Homologous chrmosomes move to the opposite sides of the cell.

telophase I

A nuclear membrane forms around each group of chromosomes

prophase II

nuclear membrane breaks apart

metaphase II

sister chromatids line up at the center of the cell

anaphase II

sister chromatids separate

telophase II

Nuclear membrane reforms, cytoplasm divides, 4 daughter cells formed

humans diploid chromosome number

46

humans haploid chromosome number

23

number of divisions in meiosis

2

number of divisions in mitosis

1

advantage of sexual reproduction

genetic variation