Ch. 6

Chapter 6

Section 1: Chromosomes & Meiosis

Your body produces 2 types of cells....

1. Germ Cells aka Sex Cells aka Gametes

2. Somatic Cells aka body cells (all other cells in your body)

The number of chromosomes varies within species....

Humans have 23 pairs of chromosomes in each cell (46 chromosomes total)

Fruit flies have 4 pairs of chromosomes in each cell (8 chromosomes total)

Dogs have 39 pairs in each cell

Cats have 19 pairs...

No matter what species you have each chromosome has its pair (the same size and copies of the same genes)

These two pairs of chromosomes are called HOMOLOGOUS CHROMOSOMES

The EXCEPTIONS are the Sex Chromosomes... 

Fertilization happens when an egg (having 23 chromosomes, Haploid cell) combines with the sperm (having 23 chromosomes, Haploid cell) forming a DIPLOID CELL

Haploid Vs Diploid

Syndromes of Sex Linked Chromosomes

Turner Syndrome

                               

Klinefelter Syndrome

Extra Y Chromosome

Some More Info

What about Down Syndrome

 Are Men Going Extinct?

Mitosis vs Meiosis

DIFFERENCES: Meiosis has 2 Divisions & The Result are 2 GENETICALLY DIFFERENT HAPLOID cells

UNIQUE OCCURRENCE IN PROPHASE I

(CROSSOVER)

Review