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Sexual Reproduction
Question | Answer |
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Cell division G1 and G2 phase | this is when a cell doubles in organelles and cytoplasm...cell growth |
S Phase | DNA replicaton occurs, cells entering ths phase have twice as much DNA than in the other phases |
M phase | mitotic cell phase, the cell divides in two. Contains prophase, metaphase, anaphase and telophase |
Mitosis | this celluar division produces two diploid daughter cells that are genetically identical |
Meiosis | produces daughter cells that contian half the genetic material |
Diploid cells | contains two copies of every chromosome, forming a pair of homologous chromosomes |
homologous chromosomes | contain genetic information from both parents |
Mitosis: Prophase | First the nucleoli disappears and the chromatin condense. Then the nuclear envelope breaks down, lastlymitotic spindle is assembled |
Mitosis: Metaphase | Sister chromatids align on metaphase plate |
Mitosis: Anaphase | Chromosmoes separate into chromatids. Microtubules connect to chromatids (now chromosomes), shorten and pulls them to opposite polls. Lastly formation of cleave furrow. |
Mitosis: Telophase | New nuclear envelope develops around each pole forming two nuclei. Cytokineis occurs |
diploid | two copies of each chromosome = 46 |
Prophase I | Nucleolus disappears, chromatin condense into chromosomes, envelope starts to break down. Homologous chromosomes pair up forming tetrads, crossing over occurs. |
Metaphase I | homologous pairs of chromosomes are spread across the metaplate |
Anaphase I | Homologous chromosomes separate, and sister chromatids remain together |
Telophase I | Cell divides into two cells. At this point the cells are considered to be haploid |
Prophase II | Nuclear envelope disappears and the spindle developes |
Metaphase II | Chromosomes allign on metaphase plate centromeres divid, leaving pairs of sister chromatids |
Anaphase II | Sister chromatides pulled to opposite polls by spindle fibers |
Telophase II | Nuclear membrane forms around eahc new cucleous. Four halpoid cells have been produced. |
nondisjuncton | failure to separate during meosis |