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40 Cards in this Set
- Front
- Back
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Cell Division |
All cells reproduce by division. |
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Why do cells divide? |
Organismal reproduction Growth Repair |
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Asexual Cell Division |
Occurs in all organisms. Daughter cells are identical copies of mother cell (clones). Mitosis (division of nucleus in eukaryotes) Binary fission (division in half in prokaryotes) |
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Sexual Reproduction |
Meiosis- daughter cells are not identical copies of mother cell. Only in eukaryotes. |
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Prokaryotic Cell Division |
Binary fission. DNA is duplicated (single chromosome). One chromosome moved to each side of cell. Cell split in two (takes 20 min). Results in two genetically identical daughter cells. |
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Eukaryotic Cell Division |
Asexually by mitosis. Cell grows and duplicates organelles and DNA. DNA moved to opposite sides of cell. Cell split in two (takes 90 min) Results in two genetically identical daughter cells. |
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What does cell division have to do with cancer? |
Occurs when cell division becomes uncontrolled. |
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Tumor |
A mass of cells that exhibit abnormal growth with no function (cancerous). |
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Benign tumor |
(noncancerous) doesn't affect surrounding tissues. |
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Malignant tumor |
(cancerous) invades surrounding tissues. |
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Metastatic tumor |
(cancerous) cells break away from a malignant tumor and start a new cancer at another location. Travels through circulatory system and lymphatic system. |
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Cancer is... |
loss in regulation of cell division (mitosis) and/or cell death (apoptosis) |
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Cancer cells differ from normal cells |
Divide when they shouldn't. Invade surrounding tissues. Move to other locations in the body. |
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Top 3 cancer in men |
Prostate, lung, and rectum/colon |
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Top 3 cancer in women |
breast, lung, colon/rectum |
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Risk factors |
increase a person's risk of developing a disease tobacco with carcinogens alcohol high fat low fiber diet lack of exercise obesity age increase weakening immune system ovarian cells that divide frequently |
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How do cancerous cells develop? |
Loss in regulation of... Mitosis- increase in number of cells. Programed cell death (apoptosis) decrease in number of cells. Both controlled by genes. |
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Growth and repair |
Mitosis Single cell to an adult of 3 trillion cells Also how wounds heal |
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Cell cycle |
Tells cells when it's time to divide. Ordered sequence of stages. Preparatory and division phases. One cell to two identical cells. |
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Cell cycle has three steps |
Interphase- Growth, organelles/DNA replication Mitosis- The copied chromosomes are moved into daughter nuclei (occurs in somatic or body cells) Cytokinesis- the cell is split into 2 daughter cells |
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Interphase |
Three phases. G1: cell grows, organelles duplicate S: DNA replicates G2: cell makes proteins needed to complete mitosis Most of the cycle is spend in interphase (prep stage) |
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Gene |
Section of DNA that has the instructions for making all proteins. (we have 24,000 genes) |
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DNA |
Adenine (A) pairs with thymine (T) Cytosine (C) pairs with guanine (G) |
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Chromosome |
One molecule of DNA is wrapped around proteins to form a chromosome containing hundreds of genes. Eukaryotic chromosome=an organized molecule of DNA+protein Can be coiled to various extents (condensation) |
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Duplicated chromosomes |
Held together at the centromere called sister chromatids. Duplicated through DNA replication. |
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DNA replication |
DNA molecule split up the middle of the helix. Nucleotides added to each side. Result is two identical daughter molecules, each with one parental strand and one new strand (semiconservative replication) |
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Chromatid |
Copies of linear DNA molecule wound around proteins. |
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DNA Polymerase |
The enzyme that replicates DNA |
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Point mutations |
Mutations can occur during DNA Replication Chemical changes in just one base pair of a gene and occur in two categories: Base-pair substitutions- replace one nucleotide and its partner with another pair of nucleotides. Insertion or deletion- are additions or losses of nucleotides in a gene. |
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What happens in mitosis |
DNA evenly split between two daughter cells. Cytoplasm and Organelles evenly split between two daughter cells. Parent cell divides into two identical daughter cells. |
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Mitosis followed by cytokinesis which splits the two nuclei into two daughter cells |
Four stages: Prophase Metaphase Anaphase Telophase |
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Prophase |
Chromosomes condense. Nuclear envelope disappears. Microtubules pull the chromosomes around during cell division. Animal cells: microtubules attached to centrioles at the poles of the cell. |
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Metaphase |
Chromosomes are aligned across the middle of the cell by microtubules. "metaphase plate" |
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Anaphase |
Centromeres split. Sister chromatids are pulled apart toward opposite poles. |
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Telophase |
Nuclear envelopes reform around chromosomes. Chromosomes revert to uncondensed form. |
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Cytokinesis |
Two daughter cells are formed from the original one. After cytokinesis, cells reenter interphase. Animals: proteins pinch the original cell into two new cells. |
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Cytokinesis in plants |
Starts with vesicles forming the cell plate. New cell wall formed between the cells forming daughter cells. The cell wall is made from cellulose. |
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Cell Cycle control |
Normal cells halt at checkpoints Proteins survey the condition of the cell. 3 Checkpoints: G1, G2, and metaphase. |
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Growth factors |
stimulate cells to divide They bind to receptors to trigger a response from a cell. |
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G0 phase |
Cell stops dividing or a stage of quiescence |
