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Chapter 5 vocab
Question | Answer |
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cell cycle | the life cycle of the cell; in eukaryotes, it consists of a cell-growth period in which DNA is synthesized and a cell-division period in which mitosis takes place |
mitosis | in eukaryotic cells, a process of cell division that forma two nuclei, each of which has the same number of chromosomes |
cytokinesis | the division of the cytoplasm of a cell; it follows the division of the cell's nucleus by mitosis or meiosis |
chromosome | in a eukaryotic cell one of the structures in the nucleus that are made up of DNA and protein; in a prokaryotic cell the main ring of DNA |
histone | a type of protein molecule found in the chromosomes of eukaryotic cells but not prokaryotic cells |
chromatin | the substance that composes eukaryotic chromosomes; it consists of specific proteins DNA and small amounts of RNA |
chromatid | one of the 2 strands of a chromosome that become visible during meiosis or mitosis |
centromere | the region of the chromosome that holds the 2 sister chromatids together during mitosis |
telomere | the region at the tip of a chromosome; a region of repeating DNA sequence that forms one of the end points of the DNA segment that makes up a chromosome |
prophase | first phase of mitosis when chromatin condenses, the nuclear envelope breaks down, the nucleolus disappears, and the centrosomes and centrioles migrate to opposite sides of the cell |
metaphase | 2nd phase of mitosis when spindle fibers align the chromosomes along the cell equator |
anaphase | 3rd phase of mitosis during which chromatids separate and are pulled to opposite sides of the cell |
telophase | last phase of mitosis when a complete set of identical chromosomes is positioned at each pole of the cell, the nuclear membranes start to form, the chromosomes begin to uncoil, and the spindle fibers disassemble |
growth factor | broad group of proteins that stimulate cell division |
apoptosis | programmed cell death |
cancer | a type of disorder of cell growth that results in invasion and destruction of surrounding healthy tissue by abnormal cells |
benign | having no dangerous effect on health, especially referring to an abnormal growth of cells that are not cancerous; remain clustered; cured by removal |
malignant | cancerous tumor in which cells break away and spread to other parts of the body, causing harm to the organism's health |
metastasize | to spread by transferring a disease-causing agent from the site of the disease to other parts of the body |
carcinogen | substance that produces or promotes the development of cancer |
asexual reproduction | reproduction that does not involve the union of gametes and in which a single parent produces offspring that are genetically identical to the parent |
binary fission | a form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size |
tissue | a group of similar cells that perform a common function |
organ | a collection of tissues that carry out a specialized function of the body |
organ system | two or more organs that work in a coordinated way to carry out similar functions |
cell differentiation | the process by which a cell becomes specialized for a specific structure or function during multicellular development |
stem cell | cell that can divide for long periods of time while remaining undifferentiated |
Kinases | enzymes that when activated, transfer a phosphate group from one molecule to a specific target molecule which increases energy of the target molecule or changes its shape |
Cyclins | group of proteins that are rapidly made and destroyed at certain points in the cell cycle (checkpoints) |
hormones | growth factor |
Platelets | sticky fragments of bone marrow that form clots to stop bleeding |
Erythropoietin | stimulates the production only of cells that will become red blood cells (need more in mtns. bc less O2) |
Oncogenes | accelerate the cell cycle |
Radiation... | kills cells & shrinks tumors |
Chemotherapy | drugs that can kill actively dividing cells |
Totipotent | can grow into any other cell type |
Pluripotent | can grow into any cell type except for totipotent |
Multipotent | can grow only into cells of a closely related family |