Term
| What are Hela cells and why are they so significant? |
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Definition
| Hela cells are cancer cells from a woman long ago that are rapidly dividing and are still being used to this day to do research. |
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Term
| What three major events must occur before cytokinesis can? |
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Definition
| Reproductive signal , replicating of DNA, cell segregation |
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Term
| How does cell division differ from eukaryotic and prokaryotic cells? |
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Definition
| Eukaryotic uses bianry fission and prokarotic uses mitosis or meiosis |
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Term
| What are the three steps of interphase? |
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Definition
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Term
| What happens in G1 of interphase? |
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Definition
| each cell is single and unreplicated and gets the signal to continue in the cycle |
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Term
| What happens in S of interphase? |
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Definition
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Term
| What happens in G2 of interphase? |
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Definition
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Term
| Explain how an unduplicated chromosome becomes a duplicated chromosome containing sister chromatids? |
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Definition
| It replicates in the S phase |
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Term
| How do sister chromatids compare genetically? |
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Definition
| They are genetically identical |
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Term
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Definition
Interphase is the preparation for mitosis
Mitosis is nuclear division |
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Term
| What do condensins do for chromosome structure? |
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Definition
| Coat the DNA molecules and make them more compact |
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Term
| What do histones do for chromosome structure? |
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Definition
| Package DNA (holds it together) |
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Term
| What do cohesin do for chromosome structure? |
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Definition
| Hold sister chromatids together |
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Term
| Compare the number of chromosomes and the amount of DNA contained in the nucleus during the G1 phase vs. the G2 phase |
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Definition
Chromosome count doesn't change
DNA 1:2 |
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Term
| What are the 4 stages of mitosis? |
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Definition
| Prophase, Metaphase, Anaphase, and Telophase |
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Term
| What 2 roles do microtubules play? |
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Definition
1) form spindle
2) attach to two sister chromatids to make sure they end on opposite poles |
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Term
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Definition
Centromere- link sister chromatid
Centrosome- main microtubule organizer |
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Term
| What happens in prophase? |
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Definition
| Chromatins are compacting, nuclear envelope is decomposing, spindle starts to form |
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Term
| What happens in metaphase? |
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Definition
| Centromeres align at the cells equator |
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Term
| What happens in anaphase? |
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Definition
| Paired sister chromatids separate, new daughter chromosomes move toward poles |
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Term
| What happens in telophase? |
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Definition
| Daughter chromosomes reach the poles, nuclear envelope and nucleoli re-form, chromatins decondenses |
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Term
| Why are cytokinesis and mitosis different? |
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Definition
| Mitosis is nuclear division and cytokinesis is the splitting of the cytoplasm after mitosis is done |
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Term
| What is the main biological function of mitosis |
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Definition
| to segregate copies of genetic information |
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Term
| How does cytokinesis differ between animal and plant cells? Why does it differ? |
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Definition
In animal cells it has a contractile ring In plant cells it starts with membranous vesicles from the golgi apparatus appear along the plane of cell division
They differ because of the plant cells rigid cell wall |
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Term
| What is the genetic state of offspring after asexual reproduction? What is a clone? |
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Definition
Genetic clones
Identical copy of parent |
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Term
| What is the biological function of sex? |
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Definition
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Term
| Compare somatic cells with gametes. |
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Definition
somatic cells are not needed for reproduction and are made in mitosis
Gametes are cells made for sex and made in meiosis |
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Term
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Definition
| When two haploid gametes are fused to form a zygote |
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Term
| How many nuclear divisions in meiosis vs mitosis |
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Definition
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Term
| What is the main function of meiosis? |
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Definition
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Term
| What are four major differences between meiosis and mitosis? |
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Definition
| MITOSIS: 1 Cell Division. 2 Daughter Cells. Daughter Cells are identical to Parent Cells. No crossing over. MEIOSIS: 2 Cell Division. 4 Daughter Cells. Daughter Cells are haploid. Crossing over takes place. |
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Term
| Explain synapsis during prophase I and how this leads to crossing over. What chromosomes typically ‘cross over’? |
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Definition
| The homologous chromosomes pair by adhering along their lengths, the four chromatids of each pair of homologous chromosomes form a tetrad. |
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Term
| How is meiosis II similar to mitosis? How is meiosis II different from mitosis? |
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Definition
In both cases chromosomes line up and sister chromatids are separated by the action of the spindle fibers. The daughter cells are genetically identical to one another.
end result meiosis produces 4 cells with 1/2 the normal number of chromosomes and mitosis only 2 cells with the normal complement of chromosomes |
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Term
| What is nondisjunction and what genetic problems can it lead to? |
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Definition
| Failure of chromosome pairs or sister chromatids to split properly;Aneuploidy |
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Term
| What is nondisjunction and what genetic problems can it lead to? |
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Definition
| Failure of chromosome pairs or sister chromatids to split properly;Aneuploidy |
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Term
| What is down syndrome? Why does it happen? |
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Definition
| An extra 21st chromosome that leads to intellectual impairments, because of Aneuploidy |
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Term
| What 3 ways does sexual reproduction lead to genetic variations? |
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Definition
| Crossing over in Prophase 1, Random assortment in metaphase 1, fertilization of random gamete |
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Term
| Compare and contrast necrosis with apoptosis. |
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Definition
| Necrosis- cell death from environmental causes Apoptosis- genetically programmed cell death |
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Term
| How can the lack of apoptosis be bad for a human? |
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Definition
| overpopulation of cells, more prone to diseases |
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Term
| What 2 ways do cancer cells differ from normal cells? |
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Definition
| Cancer cells lose control over cell division, cancer cells can migrate to other locations in the body |
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Term
| What is the difference between a benign tumor and a malignant tumor? |
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Definition
| Benign- look like parent tissues, stays in the same location Malignant- don’t look like parent tissue, can move locations |
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Term
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Definition
| Malignant growth of cells at a distance from primary site |
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Term
| What are oncogenes and what is their role in cancer development? |
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Definition
| Negative regulators, inactive in cancer cells |
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Term
| What are tumor suppressors and what is their role in cancer development? |
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Definition
| Is a gene that protects a cell from one step on the path to cancer. When this gene mutates to cause a loss or reduction in its function, the cell can progress to cancer |
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Term
| Describe how one cancer drug functions in the cell. |
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Definition
| Paclitaxel- interferes with the mitotic spindle, preventing the chromosomes from dividing which keeps cancer cells from dividing. But it also prevents other cells from dividing. |
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