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DNA and Chromosomes
Biology I
Term | Definition |
---|---|
Cell Cycle | Is the regular pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells |
Mitosis | Is the division of the cell nucleus and its contents. |
Cytokinesis | Is the process that divides the cell cytoplasm. |
Chromosomes | Is one long continuous thread of DNA that consists of numerous genes along with regulatory information. |
Histones | At almost all times during the cell cycle, each of your chromosomes is associated with a group of proteins. |
Chromatin | At this stage--the "spaghetti" stage-- the loose combination of DNA and proteins. |
Chromatid | One half of a duplicated chromosome. |
Centromere | A region of the condensed chromosomes that looks pinched. |
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 | Also called body cells, make up most of your body tissues and organs. |
Gametes | Are sex cells-- ova, or eggs, in the female, and the spermatozoa, or sperm cells, in the male. |
Homologous Chromosomes | Are two chromosomes-- one inherited from the mother, one from the father-- that have the same length and general appearance. |
Autosomes | Chromosomes that contain genes for characteristics not directly related to the sex of the organism. |
Sex chromosomes | That directly control the development of sexual characteristics. |
Sexual reproduction | Involves the fusion of two gametes that results in off-spring that are a genetic mixture of the both parents. |
Fertilization | The actual fusion of an egg and a sperm cell. |
Diploid | Means a cell has two copies of each chromosome: one copy from the mother, and one from father. |
Haploid | Means that a cell only has one copy of each chromosome. |
Meiosis | Is a form of nuclear division that divides a diploid cell into haploid cells. |
Gametogenesis | Is 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. |
Traits | Are distinguishing characteristics that are inherited, such as eye color, leaf shape, and tail length. etc. |
Genetics | Is the study of biological inheritance patterns and variation in organisms. |
Purebred | If a lone of plants has self-pollinated for long enough, that line becomes genetically uniform. |
Cross | In genetics, the mating of two organisms. |
Law of segregation | Organisms inherit two copies of each gene, one from each parent. Organisms donate only one copy of each gene in their gametes. Thus, the two copies of each gene segregate, or separate, during gamete formation. |
Bacteriophage | Or "phage" for short, takes over a bacterium's genetic machinery and directs it to make more viruses. |
Nucleotides | The small units, or 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 (T) always pairs with Adenine (A), and Cytosine (C) always pair with Guanine (G) |
Replication | This process by which DNA is copied during the Cell Cycle. |
DNA polymerases | A group of enzymes that bond together new nucleotides together. |