-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)
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
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
Fertilization = combining the genes of two different parents, offspring contain variation due to crossing over and independent assortment
-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)
GAMETOGENESIS - process of creating gametes ( Oogenesis & Spermatogenesis )
Haploid
Life Cycle |
Diploid Life Cycle (animals) |