Chapter 11: Reproduction and Meiosis

Asexual reproduction

Organisms copy their DNA and split the contents of the cell in two.

Sexual reproduction

Requires two parents for a sperm cell and egg cell.

Genetic Variability

Result of sexual reproduction

Meiosis

The process where haploids are generated from a diploid

4 haploid cells

Results of meiosis

Synapsis

Where homologous pairs form a

Crossing over

The end of Meiosis 1

When the cleavage furrow start cytokinesis.

Non-disjunction

Occurs in anaphase of mitosis, anaphase I and anaphase II

Monosomy

2n-1

Trisomy

2n+1

Inheritance/Heredity

The transmission of traits from one generation ot the next.

Edouard van Beneden

Discovered Meiosis

Fertilization/Syngamy

the fusion of gametes

This leads to a reductive division

Pairing of Homologous chromosomes

Prophase I

When genetic exchange occurs

Monozygotic twins

Identical. One egg, one sperm

Dizygotic twins

Fraternal, two eggs, two sperm

Nondisjunction

Errors in cell division

Structural nondisjunction

Mutations in Chromosomal structure

Where nondisjunction occurs

Anaphase

Somatic Mutation

There is a patch of the body with an affected area

What does a Trisomy in 21 create

Down syndrome

What does a Trisomy in 18 create

Edward syndrome

What syndrome does Trisomy 13 create

Patau syndrome

Gart gene

Puts out too much purine in the blood during fetal development

Turner Syndrome (X0)

The only monosomy nondisjunction humans can survive with.

Chromosome deletions

A segment of the chromosome is removed

Cri-du-chat

Deletion of the P arm of Chromosome 5

Williams Syndrome

Deletion of the Q arm on Chromosome 7

Chromosome Duplication

Doubles a particular region of a chromosome

Charcot-Marie-Tooth disease

A duplication on chromosome 17

Fragile X syndrome

When too many CGG bases are repeated

Chromosome Translocation

When one part of 1 chromosome moves to another chromosome.

What disease you get when there is a translocation between 22 → 9

Chronic Myelogenous Leukemia