Chapter 9 - Cell Cycle

Types of Cells

Somatic Cells

• Most cells in the body

• Diploid - 2 copies of each chromosome (homologous)

Gametes

• Made in sexual reproduction

• Haploid - 1 copy of each chromosome

2 Types of Cell division

Mitosis

• results in two genetically identical cells

• occurs in somatic cells

• unicellular

Meiosis

• results in four genetically unique haploid gametes

• occurs in germ cells in the gonads

how many egg cells are produced in oognium and why

1 functional egg cell

• after meiosis 1, there are 2 intermediate daughter cells produced that remain intermediate until a person hits puberty, where it continues meiosis 2

• each division in meiosis degrades ½ egg cells produced (so ½ egg cells degrades in meiosis 1 and 2/4 egg cells degrade in meiosis 2)

• at the end, only one egg cell is fertilized and the other is discarded

how many sperm cells are produced in sporatagonia

4 sperm cells

• they are “shein” quality

Functions of mitosis

• reproduction of unicellular eukaryotes

• development

• growth

• tissue renewal

The Genome

• entirety of the genetic material in a cell

chromosome structure

consists of a single double-stranded DNA molecule

extrachromosomal plasmids

carry beneficial (but non essential) genes