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DNA & Chromosomes
Term | Definition |
---|---|
Cell cycle | the regular pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells. |
Mitosis | The division of the cell nucleus and its contents |
Cytokinesis | The process that divides the cell cytoplasm. |
Chromosome | One long continuous thread of DNA that consists of numerous genes along with regulartory information. |
Histones | A group of proteins that are associated with chromosomes. |
Chromatin | The loose combination of DNA and proteins |
Chromatid | One half of a duplicated chromosome. |
Centromere | A region of the condensed chromosome that looked pinched. |
Somatic cells | Body cells |
Gametes | Sex cells |
Homologous Chromosomes | Two chromosomes-- one inherited from the mother, one from the father-- that have the same and general appearance. |
Autosomes | Chromosomes that contain genes for characteristics not directly related to the sex of an organism. |
Sex chromosomes | Directly in control of the development of sexual characteristics. |
Sexual reproduction | involves the fusion of two gametes that results in off-spring that are a genetic mixture of both parents. |
Fetilization | The fusion of the egg cell and the sperm cell |
Diploid | A cell that has two copies of each chromosome |
Haploid | A cell only has one copy of each chromosome |
Meiosis | A form of nuclear division that divides a diploid cell into haploid cells. |
Gametogenesis | The production of gametes |
Sperm | The male gamete |
Egg | The female gamete |
Polar bodies | Cells with little more than DNA that are eventually broken down |
Bacteriophage | Takes over a bacterium's genetic machinery and directs it to make more viruses |
Nucleotide | The monomers that make up DNA |
Double helix | In which two strands of DNA wind around each other like a twisted ladder |
Base pairing rules | Thymine always pairs with adenine (T--A) and cystosine always pairs with guanine (C--G) |
Replication | The process by which DNA is copied during the cell cycle |
DNA polymerases | A group of enzymes that bond new nucleotides together |