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29 Cards in this Set
- Front
- Back
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What is the cell cycle and why do cells divide? |
the regular pattern of growth, dna duplication, and cell division that occurs in eukaryotic cells; cells divide for growth, repair, and replacement |
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4 stages of the cell cycle |
Gap 1- cell growth and normal functions DNA Synthesis- copying of DNA Gap 2- additional growth Mitosis- division of the nucleus |
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What happens during interphase? |
G1 (Gap 1)- Cell growth and normal function S (Synthesis)- the copying of DNA G2 (Gap 2)- additional growth G0 (Gap 0)- a cell performs its assigned task but never divides |
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How and why do cells package their DNA? |
DNA is packaged by wrapping around histones and coiling into chromosomes. This is because DNA needs to form a chromosome in order to align and separate during mitosis. |
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What happens during cytokinesis? |
Animal- membrane forms a furrow or trench, membrane pinches closed, forming a separate cell around each nucleus Plant- cell plate forms between the two nuclei, cellulose and other materials are laid down, cytoplasm is divided evenly between daughter cells |
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Surface area to volume raitios |
Small cells have small SA:V SA increases slower than volume as the cell gets larger Larger cells are less efficient |
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Ways that cells increase their surface area to volume ratio |
thin extensions for the cytoplasm increase surface area faster than volume (cilia, folds, extensions of cell membrane) |
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What are checkpoints? |
when the cell checks itself for defective cell division |
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The three checkpoints and what happens at each |
G1- Checks for proper functioning and growth G2- Checks for proper DNA copying M- Checks for spindle fiber attachment |
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What can be learned about evolution from studying the molecules that regulate the cell cycle? |
All organisms share a common ancestry because we all use the same proteins to regulate our cell cycles. |
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mitosis |
the division of the cell nucleus and its contents |
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cytokinesis |
the process that divides the cell cytoplasm |
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chromosomes |
one long continuous tread of DNA that consists of genes and regulatory information |
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Histones |
a group of proteins that DNA wraps around at regular intervals |
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Chromatin |
a loose combination of DNA and proteins in the "spaghetti" stage of mitosis |
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chromatid |
one half of a duplicated chromosome |
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Apoptosis |
programmed cell death |
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carcinogen |
substances that can cause cancer |
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benign tumor |
cancer cells remain clustered together |
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malignant tumor |
cancer cell break away, or metastasize, and spread throughout the body |
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How is a cancer cell different from a normal cell? |
cancer cells do not perform specialized functions needed by the body, and cell division is uncontrolled in cancer cells |
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what is the product of asexual reproduction? |
genetically identical clones |
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how do prokaryotes reproduce? |
binary fission |
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4 types of asexual reproduction |
binary fission- two roughly equal parts are created budding- offspring grows from the side of the parent fragmentation- parent breaks off into pieces that each become a new individual vegetative reproduction- new plant forms from a modifies stem or root structure |
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describe the structural organization of multicellular organisms |
cell-tissue - organ - organ system - organism |
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Why do cells differentiate? |
cells must specialize, use only parts of the DNA that are needed, their location in the developing embryo helps determine what they will become |
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In a changing, unstable environment, is it more or less advantageous for an organism produced by asexual reproduction? |
Less, because cells that come from sexual reproduction have genetic diversity, whereas asexual reproduction is very fast and efficient |
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Why are stem cells unique? |
they have the ability to divide and renew themselves for long periods of time, to remain differentiated in form, and to develop into a variety of specialized cell types |
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the catholic church encourages the use of what type of stem cells in research? |
adult stem cells |
