10.1 Meiosis

-the production of haploid cells with unpaired chromosomes - word means "to diminish". -process creates gametes (sperm and eggs), cells that are haploid (1N)
-gametes combine to create a zygote which is diploid (2N)

Chromosome Structure

Each chromosome has mane alleles, or alternate forms of genes

Homologous Chromosomes - each chromosome has a match, called a homolog

Human Karyotype - chromosomes are numberd and paired according to size and banding pattern

Diploid vs Haploid

Body cells have the full set of chromosomes – they are DIPLOID (2N) 
Sex cells (sperm and eggs) have half a set – they are HAPLOID (1N)


The last set is the sex chromosomes (XX or XY)


10.2 Genetic Variation

Crossing-Over - during prophase I, homologous pairs join together (synapsis) and exchange genetic information, chromatids are no longer exact duplicates

During metaphase, chromosomes line up in PAIRS, randomly – a  phenomenon known as INDEPENDENT ASSORTMENT

independent assortment

Fertilization = combining the genes of two different parents, offspring contain variation due to crossing over and independent assortment

10.3 The Phases of Meiosis

major events

Key points of Meiosis

-The process results in 4 daughter cell
-daughter cells are haploid (N)
- cells have unique combinations of chromosomes|
- cells do not have homologous pairs

- Meiosis creates gametes (sperm and eggs)

10.4 Meiosis Compared to Mitosis

10.5 The Human Life Cycle

GAMETOGENESIS - process of creating gametes ( Oogenesis & Spermatogenesis )


Haploid Life Cycle
(protists, algae, fungi)

haploid life cycle

Diploid Life Cycle (animals)

diploid life cycle