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AP Biology
Chapter 9 - Mitosis & Meiosis guided notes, definitions
Question | Answer |
---|---|
Mitosis | A nuclear division, divides the nucleus so that both daughter cells are genetically identical |
Nuclear division | Divides the genetic material in the nucleus |
Cytokinesis | After nuclear division, divides the cytoplasm |
Gene | A segment of DNA that serves as a unit of hereditary information |
Chromotin | The complex of DNA and proteins that make up eukaryotic chromosomes |
Chromosomes | Structures in the cell nucleus that consist of chromotin and genes |
Genome | The genetic material in a cell or individual organism |
Meiosis | A nuclear division, reduction division, producing daughter cells that contain half the genetic information of the parent cell |
What is meant by the concept that cells go through a cell cycle? | Life of a cell from its origin to division into 2 new daughter cells |
What are the key roles of cell division? | Eukaryotic chromosomes, cell cycle, and mitosis |
What is the significance of chromosome replication? | They contain hundred of thousands of genes |
Phases of the cell cycle | Interphase and M phase - Interphase contains G1 (gap1), S phase (DNA synthesis), and G2 (gap 2) - M phase contains M (mitosis) and then cell ceases division |
Stages of Interphase and Mitosis | Interphase, Prophase, Prometaphase, Metaphase, Anaphase, and Telophase |
How does the spindle apparatus distribute chromosomes to the daughter cells? | It pulls them to the opposite poles |
What is the role of kinetochores and the microtubules? | Use motor proteins that "walk" chromosomes along attached microtubule |
How does cytokinesis differ in animal and plant cells? | Plant cells go through cell plate. Animal cells go through cleavage furrow |
Eukatyotic mitosis is thought to have evolved from | binary fission. |
Why is the regulation of the cell cycle critical to normal cells? | For normal growth, development, and maintenance |
What is the G1 checkpoint and where does it fit into the cycle? | It decides if DNA synthesis can begin. It's a primary decision (restriction) point, if the cell gets a "go signal" it will divide, if not the cell exits the cycle and goes to the G0 phase |
What evidence is there that regulation is chemical in nature? | Cytoplasm gets a cue from chemical signals when it's time for the cell to divide. The signals are usually proteins. |
Kinase | Enzymes that catalyze the transfer of phosphate groups from ATP to acceptor molecules |
Cyclin | Regulatory proteins whose levels oscillate during the cell cycle; activate CDKs |
CDKs | Protein kinases involved in controlling the cell cycle |
Describe the mechanism for regulating the passage of the cell into anaphase. | APC (anaphase-promoting complex) initiates anaphase by allowing degradation of the protein |
Describe what triggers mitosis from G2. | CDK associates with cyclin which forms M-CDK. M-CDK phosphorylates proteins which activate mitosis |
What is the role of ubiquitin? | Small regulatory protein |
What happens when cancer develops? | Unlimited growth, ignore checkpoints, escape apoptosis, immortality |
What is the role of p53? | Halts cell division if it detects damaged DNA |
Asexual Reproduction | Single-celled eukaryotes reproduce asexually and simple multicellular eukaryotes reproduce asexually. |
Sexual Reproduction | Involves the union of two sex cells, or gametes, to form a single cell called a zygote. |
What is the role of meiosis in sexual reproduction? | Has 2 cell divisions, produces up to 4 cells, genetic information from parents is shuffled, haploid cell has unique combination of genes. |
What is a karyotype? | Map of organisms chromosomes |
Indentify several things that can be seen with a karyotype? | You can see the chromosome makeup, how many chromosomes, if there is anything abnormal |
Products of mitosis | Produces 2 cells for growth and repairs somatic cells |
Products of meiosis | Produces 4 cells in 2 cell divisions and produces gametes |
Explain the double division of meiosis. | DNA replication create sister chromatid. They divide twice to create 4 cells. |
Independent Assortment | Homologous chromosomes in Meiosis 1 |
Random Fertilization | Any 2 parents will produce a zygote with over 70 trillion diploid cominations |
Crossing Over | Creates completely new combinations of traits in next generation. |
Differences between mitosis and meiosis. | Mitosis - 1 division, daughter cells genetically indentical to parent cell, and produces 2 cells |
Differences between mitosis and meiosis. | Meiosis - 2 divisions, daughter cells genetically different from parent, and produces 4 cells |
What is the significance of genetic variation and natural selection? | Genetic variation drives evolution. |