Sexual Reproduction

Three kinds of eukaryotic cell reproduction

Eukaryotic Life Cycles

Mitosis

Meiosis

Meiosis

Spindle Connections inCell Divisions

Overview of Meiosis

Independent AssortmentRecombination of genes located on different chromosomes

1/2 time1/2 time

A

AB

B

b

b

b

b

B

Ba

a

ABAb

aB ab

A

A

a

a

b

b

B

B

Anaphase I

Non-homologous pairs of chromosomes orient independently of one another on the metaphase plate of the spindle

Below, the relative movement of the A and B chromosomes is illustrated:

Crossing-OverRecombination of genes located on the same chromosomes

nucleus

Meiosis I Bivalent

2 paired homologues(4 chromatids)

5 cross-overs

Synaptonemal Complex

LELELELE CECE

R NR N DyadDyadDyadDyad

2 Dyads

chiasmata

chromatid

synapsing bivalent

Synaptonemal Complex Time Course

Synaptonemal Complex

Homologous Recombination

strand invasion ensures homologous nicks

Eukaryotic Life Cycle

Syngamy(Fertilization)

Syngamy

Sperm Sperm and Egg

QuickTime™ and aVideo decompressor

are needed to see this picture.

QuickTime™ and aVideo decompressor

are needed to see this picture.

QuickTime™ and aVideo decompressor

are needed to see this picture.

QuickTime™ and aVideo decompressor

are needed to see this picture.

Sperm, Egg, and Zygote

Why did sex evolve?

Review of Genetic Changes

Summary - Questions

Summary - Answers

Haploid Mitosis

Diploid Mitosis

Mitoses

Meiosis

Syngamy

Practice

Practice - Questions

Practice - Answers