haploid

a cell with one set of chromosomes

diploid

a cell with two sets of chromosomes; twice the haploid number

crossing over

when chromosomes in a tetrad swap pieces of each other, leading to genetic diversity

homologous pair

a pair of chromosomes, one from each parent, that have relatively similar structures and gene values

daughter cells

new cells produced by cell division

G1 phase

part of interphase in which the cell undergoes the most growth

M phase

stage of cell cycle in which mitosis and cytokinesis occur

prophase

first & longest phase of mitosis in which the chromosomes become visible

telophase

last phase of mitosis in which the chromatids arrive at the poles, the spindle breaks down and the nuclear envelope reforms.

metaphase I

second stage of meiosis I in which chromosomes line up double file

metaphase II

second stage of mitosis II in which the chromosomes line up across the cell.

Cyclin

proteins that help facilitate the cell cycle

fertilization

creation by the physical union of male and female gametes

mitotic spindle

this guides the DNA to the two sides of the cell during mitosis

gametes

cells produced by meiosis; another name for sex cells

G2 phase

stage of interphase in which the cell prepares for mitosis (m phase)

mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

metaphase

phase of mitosis in which the chromosomes line up in the middle of the cell and attach to the mitotic spindle

cytokinesis

process by which the cytoplasm of a cell divides; in an animal cell, it is called furrowing, in a plant cell the cell plate forms

anaphase II

The third phase of meiosis II. The sister chromatids are spearated at their centromeres and pulled to opposite sides of the cell. The number of chromosmes was reduced by half during meiosis I.

cancer

disease in which some of the body's cells multiply uncontrollably

cell cycle

set of events during which the cell grows and divides

chromatin

the messy, unwound form of DNA that is found in the nucleus prior to cell division.

centrioles

organelles that form the mitotic spindle

interphase

period of the cell cycle between cell divisions

S phase

part of interphase in which cell DNA is replicated

meiosis

cell division that produces reproductive cells in sexually reproducing organisms- creates four new sex cells with a haploid amount of chromosomes

anaphase

phase of mitosis in which the mitotic spindle pulls the sister chromatids to opposite ends of the cell

prophase I

first stage of meiosis I, where tetrads (a set of two tightly bound chromosomes) are formed and may cross over

prophase II

The first phase of meiosis II. Prophase II is identical to mitotic prophase, except that the number of chromosomes was reduced by half during meiosis I.

telophase II

The fourth and final phase of meiosis II. Telophase II is identical to mitotic telophase, except that the number of chromosomes was reduced by half during meiosis. I.