Foundations of Biology

Leads to production of male and female gametes

The division of the cytoplam into two distint cells

Leads to the production of somatic "body belonging" cells

A single long DNA that is wrapped in proteins in a highly organized manner.

number and types of chromosomes present in an organism

DNA copies in a replicated chromosome

same type of chromosomes

a section of DNA that influences one or more herditary traits in an individual

the binding of two chromatids at a specialized region of the chromosome

chromatids from the same chromosome

Nondividing phase in mitosis, cell is either growing and preparing to divide or fulfilling its specialized function in a multicellular individual

replication of genetic material is separated from the partitioning of chromosome copies during M phase, part of interphase

describes the orderly sequence of events that starts with the formation of a eurkaryotic cell

number of distinct types of chromosomes

the number of each type of chromosomes present

organisms whose cells contain just one of each type of chromosomes

Cells contain two versions of each type of chromosome

Diploid cells have one _________ and one _______

organisms with three or more versions of each type of chromosome

Phase that chromosomes condense into compact structures

In this phase, animal centrosomes complete their migration to the opposite poles of the cell

In this phase, the centromeres of the chromatids split

In this phase, the nuclear envelope begins to form around each set of chromosomes

cytokinesis begins with this in animal cells

During ______, the diploid (2n) parent cell produces two haploid (n) daughter cells

During _______, the sister chromatids of each chromosome separate and go to different daughter cells

Daughter cells become gametes through

Phases of Meiosis 1:

Homolog pairs come together in a pairing

structure that results from synasis, consisting of two homologs

In this phase, Crossing over between homologous non-sister chromatids

In this phase, paired homologs seperate and begin to migrate to opposite ends of the cell

In this phase, the homologs finish migrating to the poles of the cell

The end result of meiosis 1:

Phases of Meosis 2:

In this phase, the spindle apparatus forms & one spindle fiber attaches to the cetromere of each sister chromatid

In this phase, replicated chromosomes line up at the metaphase plate

In this phase, Sister chromatids seperate. The resulting daughter chromosomes begin moving to opposite sides of the cell

In this phase, Chromosomes arrive at opposite sides of the cell. A nuclear envelope forms around each haploid set of chromosomes, and each cell undergoes cytokinesis

Meiosis 2 results in _____ haploid cells, each with one type of chromosome

Chromosomal segments are swapped between adjacent homologs

Two pairs of non-sister chromatids are brought close together and are held there by a network of proteins

At each point where crossing over occurs, the non-sister chromatids from each homolog get physically broken at the same point and ________________

Results in four gametes with a chromosome composition different from that of the parent cells, maternal and paternal chromosomes cross over during meiosis 1

If bothe homolog or both sister chromatids move to the same pole of the parent cell, the products of meosis will be abnormal, this error is

In nondisjunction, two gametes will have an extra copy of a chromosome

In nondisjunction, two gamates will lack that chromosome

An example of trisomy, extra copy of chromosome 21

Typically do not survive to produce viable offspring

XXY, developes in males

karotype XXX

Occurs in females, their karyotype is XO (they lack the second X)