Midterm paper

CELL BIOLOGY LAB Mitosis

Pre-lab Resources Dr. Lisa Brinn

Cell Life Cycle ■ Interphase – G0 ■ Normal functions

– G1 ■ 8-12 hours ■ Prepares for division

– S ■ 6-8 hours ■ DNA replication ■ Protein synthesis

– G2 ■ 2-5 hours ■ Las minute protein synthesis

M phase Mitosis begins

Prophase

■ Begins after completed DNA replication – Early prophase ■ Centrioles move apart

– Late prophase ■ Disintegration of nuclear membrane and nucleoli ■ chromosome - called chromatids ➙ connected at centromere

Metaphase

■ Centromeres move to the metaphase plate

Anaphase

■ Centromere of each chromatid splits – Called daughter chromosomes

■ Ends ➙ daughter chromosomes arrive near centrioles at opposite ends of dividing cell

Telophase

■ Reverse of prophase – Cell prepares to return to interphase

■ Formation of nuclear membranes

■ Enlargement of nuclei – Chromosomes gradually uncoil ■ Nucleoli reappears ■ Nuclei resembles those of interphase cells

Cytokinesis

■ Telophase – End of mitosis proper

■ Cytokinesis – Division into two daughter cells

Meiosis

■ Mitosis – Division of somatic cells

■ Meiosis – Cell division - produce gametes in sexual reproduction ■ With half the genetic material of parent cells

– These can then join during sexual reproduction ➙ produce diploid zygote