lab 4 mitosis and meiosis

mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes (somatic cells)

Meosis

the process by which the number of chromosomes is reduced by half to form sex cells (gametes)

Haploid

An organism or cell having only one complete set of chromosomes.

Diploid

containing two complete sets of chromosomes, one from each parent.

Interphase

the resting phase between successive mitotic divisions of a cell, or between the first and second divisions of meiosis.

G1 phase

The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.

S phase

The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.

G2 phase

The second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

G0 phase

A nondividing state in which a cell has left the cell cycle.

prophase

kinetochore

A specialized region on the centromere that links each sister chromatid to the mitotic spindle.

non-kinetochore microtubules

they do not attach to the chromosomes to and help to move poles of cell apart

kinetochore microtubules

Connects the centrosome with the kinetochore in the centromere region of the chromosome.

aster

A radial array of short microtubules that extends from each centrosome toward the plasma membrane in an animal cell undergoing mitosis.

Cytokinesis

division of the cytoplasm

Metaphase

Anaphase

sister chromatids

Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II.

daughter chromosomes

Sister chromatids that are separated by mitosis

Telophase

The end result of mitosis and cytokinesis is

2 identical daughter cells

Prophase 1 (crossing over)

metaphase 1 (independent assortment)

anaphase 1

Homologous chromosomes separate

Telophase 1

2 daughter cells are formed, each daughter cell contains only one chromosome of the homologous pair.

Interkinesis

Period of time between meiosis I and meiosis II during which no DNA replication takes place.

prophase 2

The duplicated chromosomes and spindle fibers reappear in each new cell.

metaphase 2

Centromeres of chromosomes line up randomly at the equator of each cell.

anaphase 2

sister chromatids separate and move to opposite poles

telophase 2

A nuclear membrane forms around the chromosomes in each of the 4 new cells.