Bio 101 Chapter 7

Diploid

two sets of Chromosomein an organism, one set inherited from each parent, resulting in a total of two copies of each chromosome.

Haploid

One set of Chromosome

Gamets

Reproductive cells (egg and sperm)

Chromosome

holds genetic information

Sister Chromatids

Identical copies formed after DNA replication

Homologues

Chromosome pairs of the same length with genes in the same location

Locus

Gene in specific location

Zygote

Egg + Sperm

Prophase 1

Chromosomes condense, nuclear envelope breaks down, crossing over occurs and Tetra formation.

Metaphase 1

Pairs of homologus chromosomeline line up at the cell's equator. chromosomes

Anaphase 1

Homologous chromosomes are pulled apart to opposite poles of the cell.

Telophase 1

is the final stage of meiosis I where the chromosomes arrive at the poles, the nuclear envelope re-forms, and the cell begins to divide.

Prophase 2

a new spindle forms around the chromosomeswhich have become condensed and are generally not paired.

Metaphase 2

Chromosomes line up at the equator

Anaphase 2

Centromeres divide. Chromatids move to opposite poles of the cell.

Telophase 2

A nuclear envolpe forms around each set of chromosomes. The cytoplasm divides.

Crossing Over

Occurs between non sister chromatids of homogolus chromosomes during prophase 1.

Exchange of genetic material.

Mix of Paternal and Maternal

Does not create new, instead combines alleles

Independent Assortment

random line up that happens in metaphase 1 and anaphase 1. Only occurs in Meiosis 1.

Chiasmata

The part or place where chromosomes are crossed over when exchanging genetic information

Autosomes

22 pairs of chromosome. One set from each from parent. Excludes Sex chromosome

Nondisjunction

When a cell receives too many or too few during the separation.

Trisomy

Three copies of chromosome (extra chromosome-genetic error)

Monosomy

Only one copy of a chromosome.(genetic error)

Autosomal Dominant

Trait will be passed down in the first Generation. YY

Autosomal recessive

yy-