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DNA and Chromosomes
Biology
| 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 regulatory information. |
| Histones | A group of proteins associated with each chromosome. |
| Chromatin | The loose combination of DNA and proteins. |
| Chromatid | One half of a duplicated chromosome. |
| Centromere | A region of the condensed chromosome that looks pinched. Sister chromatids are held together at the centromere. |
| Telomeres | The ends of DNA molecules form structures called telomeres, which are made of repeating nucleotides that do not form genes. |
| Prophase | Chromatin condenses into tightly coiled chromosomes. |
| Metaphase | The spindle fibers attach to a protein structure on the centromere of each chromosome and align the chromosomes along the cell equator, around the middle of the cell. |
| Anaphase | Sister chromatids separate from each other. |
| Telophase | A complete set of identical chromosomes is positioned at each pole of the cell. |
| Somatic cells | Make up most of your body tissues and organs. |
| Gametes | Sex cells: ova, or eggs, in the female, and spermatozoa, or sperm cells, in the male. |
| Homologous Chromosomes | Two chromosomes that have the same length and general appearance. |
| Autosomes | Chromosomes that contain genes for characteristics not directly related to the sex of an organism. pairs 1 through 22 |
| Sex chromosomes | Directly control the development of sexual characteristics. |
| Sexual Reproduction | Involves the fusion of two gametes that results in offspring that are a genetic mixture of both parents. |
| Fertilization | The actual fusion of an egg and a sperm cell. |
| Diploid | A cell has two copies of each chromosome. |
| Haploid | A cell has only 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. Smaller than egg. |
| 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. |
| Nucleotides | Monomers that make up DNA. |
| Double Helix | Two strands of DNA wind around each other like a twisted ladder. |
| Base pairing rules | T always pairs with A and C always pairs with G. |
| Replication | DNA is copied during the cell cycle. |
| DNA polymerase | A group of enzymes that bond the new nucleotides together. |