Honors Biology Unit 3.5: Cell Division and Mitosis

Cell Division

process by which a single cell divides to produce two identical offspring cells

Mitosis

division of the nucleus and genetic material

Cytokinesis

division of the cytoplasm

Chromosomes

condensed structures in the nucleus that carry genetic material in the form of DNA

Sister Chromatids

the paired structures that make up an X-shaped, replicated chromosome

Centromere

near the center of a chromosome, spot where the sister chromatids are attached

Chromatin

long, uncondensed strands of DNA wrapped around proteins called histones

Histone Proteins

DNA coils around these proteins in chromatin

Interphase

longest phase of a cell's life cycle; when it carries out its regular activities; growth and DNA replication occur

G1 phase

sub-stage of interphase in which the cell increases in size, organelles increase in number

S phase

sub-stage of interphase in which cell makes a copy of the DNA in its nucleus; centrioles replicate

G2 phase

sub-stage of interphase in which additional cell growth occurs; cell is preparing to enter mitosis

Prophase

First phase of mitosis in which duplicated chromosomes condense and mitotic spindle fibers begin to form; nuclear membrane disappears

Spindle Fibers

Special microtubules made by centrioles which connect to centromeres and pull apart chromosomes.

Asters

Microtubules and fibers that radiate out from the centrioles and anchor them in mitosis

Cleavage Furrow

The area of the cell membrane that pinches in and eventually separates the dividing cell

Cell Plate

Structure that forms across the midline of a dividing plant cell; location where the new cell wall forms during cytokinesis.

Metaphase

Phase of mitosis in which the chromosomes line up across the center/equator of the cell

Anaphase

Phase of mitosis in which the chromosomes separate and begin to move to opposite ends of the cell

Telophase

Cell finishes dividing, chromosomes lengthen and become thinner, nuclear membrane reappears, cytoplasm gets divided up evenly