Mitosis

Nuclear division process that halves the chromosome number. Basis of sexual reproduction.

Nuclear division mechanism that maintains the chromosome number. Basis of body growth, tissue repair and replacement in multi-celled eukaryotes; also asexual reproduction in some plants, animals, fungi, and protists

sex cells: eggs or sperm

growth, repair and reproduction

The 23rd pair...homologs can be different XX or XY

every pair of chromosomes except the sex chromosomes. they deal with everything else...homologs are alike

how bacteria reproduce. They duplicate their DNA and split

Two: mitosis, and meiosis. mitosis reproduces every other body cells (growth (cells added for growth--not just getting cells bigger), repair and reproduction in single-celled organisms). Meiosis is for sexual reproduction

division of the nucleus

division of the cytoplasm

binary fission. Duplicate their DNA (aka chromatin) then split

is DNA and associated proteins in a long, thin, hair-like form, rarely visible with a microscope

A structure that consists of DNA and associated proteins; carries part or all of acell’s genetic information

chromatin is long, thin and hair-like DNA that is rarely visible with a microscope. Chromosomes are the shortened, condensed, coiled DNA that is readily visible with a microscope.

Constricted region in a eukaryotic chromosome where sister chromatids are attached.

Chromosomes that have 2 of each chromosomes. They are two copies of the same chromosome

One of two attached members of a duplicated eukaryotic chromosome

when cells have only half of the homologous pairs of chromosomes (sex cells)

when cells have both members of homologous pairs (mitosis)

chromosomes that have 2 copies of each

pictures scientists take of chromosomes which they cut and paste to match pairs. Example amniocentisis

• G1 (growth phase)
• S (dna duplicates)
• G2 (2nd growth phase)
• M (Mitosis)
• (G1, S, G2 are interphase. cells stay in interphase most of the time)

• Prophase
• Metaphase
• Anaphase
• Telophase

• –Centrioles
• separate (no centrioles in plants)

• –Spindle
• fibers form

• –Nuclear
• envelope and nucleolus disappears

• –Chromatin
• thickens into chromosomes

• –Spindle
• is complete

• –Sister
• chromatids line up & down the middle along the cell’s equator

Sister chromatids separate and move towards opposite ends of the cell

cancer

helps cancer cells divide uncontrollably

neoplasm forming masses of abnormal cells

In a sheath, contained

not in a sheath and spreads

Brac 1 and Brac 2

malignant cells spreads to and disrupts function in other body tissues

• –Cytokinesis
• takes place

• –Spindle
• fibers dissappear

• –Nuclear
• envelope and nucleolus reform

• –Chromosomes
• unwind and uncoil back into chromatin

sex organ cells (testes and ovary)

regular body cells