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Bio 1100 week 4
Chromosomes & The Cell Cycle
| Question | Answer |
|---|---|
| Chromatid | What chromosomes divide into during cell division. |
| Homologous chromosomes | The cell has 2 sets of each chromosome; 1 from father and 1 from mother. These chromosomes in a homologous pair have the same genes at the same loci but possible different alleles. |
| Haploid cells | Found in Gametes and have 1 set of chromosomes. |
| Diploid Cells | Found in all body cells, except gametes. 2 sets of chromosomes. |
| Functions of Mitosis | Growth and repair |
| Functions of Meiosis | Reduction in half of the number of chromosomes during gametogenisis. |
| Daughter cells of Meiosis are ______ | Haploid. |
| Daughter cells of mitosis are _____ | Diploid. |
| ECC Gap 1 | The cells primary growth phase. Normal cellular functions take place. (making proteins, getting rid of waste etc.) |
| ECC Gap 0 | Some cells pause in G1 phase and enter a state called G0 which is a resting phase. |
| ECC S phase (DNA synthesis) | Preparation for division begins. Every chromosome creates an exact duplicate of itself in a process called replication. |
| ECC Gap 2 | Second period of growth and preparation for cell division. |
| ECC Mitosis | The parent cell's nucleus, with its duplicated chromosomes divides. |
| ECC Cytokinesis | The cytoplasm is divided into two daughter cells, each of which has a complete set of the parent cell's DNA and other cellular structures. |
| Mitosis Step 1 Prophase | Nuclear envelope disintegrates, chromosomes condense, mitotic spindle forms. |
| Mitosis Step 2 Metaphase | Chromosomes align on metapahase plate. |
| Mitosis Step 3 Anaphase | The 2 sister chromatids of each chromosome part and migrate towards opposite ends of the cell as daughter chromosomes. |
| Mitosis Step 4 Telophase / Cytokinesis | Telophase: Chromosomes uncoil, nuclear envelope reforms. Cytokinesis: Cytoplasm divides, 2 genetically-identical daughter cells form. |
| Kinetochore | A complex of proteins associated with the centromere of a chromosome during cell division, to which the microtubules of the spindle attach. |
| Sister chromatids | The 2 identical copies formed by the replication of a single chromosome. |
| Gametes | A mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote. |
| Gametogenisis | Biological process by which diploid or haploid cells undergo cell division and differentiation to form mature haploid gametes. |
| Meiosis Prophase 1 | chromosomes condense, mitotic spindle forms, pairs of homologous chromosomes connect to each other, and non sister chromatids exchange DNA segments (crossing over) |
| Meiosis Metaphase 1 | Pairs of homologous chromosomes randomly line up at metaphase plate (independent assortment) |
| Meiosis Anaphase 1 | Each chromosome separates from its homologous, guided by the microtubules of the spindle. |
| Meiosis Telophase 1 / Cytokinesis 1 | Chromosomes arrive at the cell poles / Two haploid cells form. |
| Meiosis Prophase 2 | New spindle forms in each cell. |
| Meiosis Metaphase 2 | Chromosomes align on the metaphase plate. |
| Meiosis Anaphase 2 | The 2 sister chromatids of each chromosome part and migrate towards opposite ends of the cell as daughter chromosomes. |
| Meiosis Telophase 2 / Cytokinesis 2 | Nuclear envelope reforms / four genetically different haploid daughter cells form. |
| Crossing over | Exchange of genetic material between homologous chromosomes. |
| Tetrads | group set of 4. |
| How is sex determined in humans | Individual have two copies of the sex chromosomes in every cell. Females have two copies of the X chromosomes. Males have one X chromosome and one Y chromosome. |
| Define meiotic non-disjunction and aneuploidy. | chromatids join together abnormally when they shouldn't causing the number of chromosomes in one cell to increase. |
| Provide examples of genetic condition caused by an abnormal amount of chromosomes. | Down syndrome. |
| How is sex determined in Bees, ants and wasps. | Sex is determined by the number of chromosome sets an individual possesses. |
| How is sex determined in birds. | Mother determines sex |
| How is sex determined in turtles. | Sex is determined by the temperature at which the eggs are incubated. |
| aneuploidy | abnormal # of chromosomes. |
| If non-disjunction of a chromosome pair occurs in meiosis 2, what will be the result at the completion of Meiosis. | 25% of the gametes will be n+1, 25% will be n-1, and 50% will be normal. |
| A human skin cell contains 46 chromosomes. Before mitosis begins, this cell must duplicate its genetic material. What are the products of this duplication. | 92 chromatids, in 46 chromosomes. |