| Question | Answer |
| translocation | Attachment of a chromosomal fragment to a non-homologous chromosome |
| inversion | Fragment reattaches to the original chromosome but in the reverse direction |
| duplication | Fragment from one chromosome joins to a sister chromatid or homologous chromosome |
| deletion | Fragment of a chromosome is lost |
| 2 ways nondisjunction can happen | In Meiosis I: Results in 2 gametes with n+1, 2 with n-1. In Meiosis II: Results in 2 normal games, 1 with n-1, 1 with n+1 |
| nondisjunction | Occasional mishap in meiotic spindle distributing chromosomes to daughter cells. Chromosome pairs fail to separate. Explains how abnormal chromosome numbers come about |
| trisomy 21 | Three number 21 chromosomes, 47 total. Down Syndrome. Person with an extra copy of chromosome 21. Characteristic set of symptoms |
| 3 sources of genetic variability in sexually reproduction organisms | Independent orientation. Random fertilization. Crossing over |
| 3 sources of genetic variability in sexually reproduction organisms | Independent orientation. Random fertilization. Crossing over |
| genetic recombination | Production of gene combinations from those carried by the original chromosomes |
| chiasma | The sites of crossing over. X-shaped regions. Where two homologous chromosomes area attached to each other |
| crossing over | An exchange of corresponding segments between two homologous chromosomes. Produces new combinations of genes. Occurs in prophase I of meiosis |
| random fertilization | Homologous chromosomes can bear two different kinds of genetic information. Causes variation among offspring |
| independent assortment | Arrangement of homologous pairs in meiosis I. Random, causes variation |
| Compare the differences of mitosis and meiosis | Mitosis: Growth, repair asexual reproduction, 2 Identical daughter cells, One nuclear division. Meiosis: Sexual reproduction, 4 Haploid daughter cells, 2 nuclear divisions, Meiosis 1: Tetrads, crossing over |
| list the steps of meiosis II | Prophase, Metaphase, Anaphase and Telophase II occur as in mitosis |
| cytokinesis | Chromosomes uncoil. Nuclear envelope re-forms |
| telophase 1 | Chromosomes arrive at the poles of the cell |
| anaphase 1 | Migration of chromosomes toward the two poles of the cell. Sister chromatids remain attached at the centromeres |
| metaphase I | Chromosome tetrads align on metaphase plate. Spindle microtubules attached to kinetochores at the centrosomes. Each tetrad poised to move toward opposite poles |
| synapsis | Homologous chromosomes come together as pairs. Tetrads formed |
| prophase 1 | 90% of meiotic division. Chromatin coils up. Synapsis. Chromosomes become visible. Crossing over occurs. Nucleoli disappear |
| meiosis | Produces haploid gametes in diploid organisms. Preceded by duplication of chromosomes. 2 consecutive cell divisions. Results in 4 daughter cells |
| zygote | Fertilized egg. Diploid. Two haploid cells come together |
| gametes | Single set of chromosomes. 22 autosomes, plus a single sex chromosome. Haploid cells, Haploid cell number: n=23 Keep chromosome number from doubling each generation |
| Diploid cell number for humans | 2n = 46 |
| diploid cell | Any cell with two homologous sets of chromosomes |
| autosomes | Other 22 pairs of chromosomes that do not determine sex |
| sex chromosomes | Important. Determine sex. Female = XX. Male = XY. 23 chromosome |
| locus | Located at a particular place |
| homologous chromosomes | Two chromosomes composing a pair. Carry genes controlling the same inherited characteristics |
| somatic cell | Typical body cell. 46 chromosomes. 23 pairs |
| how are tumors treated | Surgically removed. High-energy radiation: Damages DNA in cancer cells much more than it does in normal cells. Some side affects if damages normal cells. Chemotherapy: Drugs used that disrupt cell cycle, Cause cell to stop actively dividing past metaphase. Side affects include nausea, hair loss, susceptibility to infection |
| leukemias and lymphomas | Blood-forming tissues |
| sarcomas | Arise in tissues that support the body, such as bone and muscle |
| carcinomas | Originate in external or internal coverings of the body |
| how are cancers named | based on site of origin |
| metastasis | Spread of cancer cells via the circulatory system beyond their original site |
| malignant tumor | Can spread into neighboring tissues and other parts of the body, displacing normal tissue and interrupting organ function. Can cause blood vessels to grow toward the tumor. Tumor cells may enter blood and lymph vessels of the circulatory system and move to other parts of the body |
| benign tumor | Remains at original site. Usually treated with surgery. Can cause problems if it grows in and disrupts certain organs |
| tumor | Formed by abnormally growing mass of body cells |
| cancer | Disease of cell cycle. Cells do no respond normally to control systems, divide excessively. Caused by single cell undergoing transformation, converting it to a cancer cell. Usually destroyed by immune system |
| 3 major checkpoints with stop and go-ahead signals that regulate the cycle | G1, G2, M. G1 most important. If denied, enters G0 phase (non-dividing) |
| cell cycle control system | Cyclically operating set of molecules in the cell that both triggers and coordinates key events in the cell cycle |
| anchorage dependence | Must be in contact with solid surface to divide |
| density-dependent inhibition | Crowded cells stop dividing. Form single layer and then stop. Physical contact of cell-surface proteins responsible for inhibiting cell division |
| growth factor | Protein secreted by certain body cells that stimulates other cells to divide. At least 50 different types. Different cell types respond to different growth factors |
| cytokinesis plant cell | Vesicles containing cell wall material collect at the middle of the parent cell. Form cell plate which grows outward and fuses with cell membrane |
| cleavage furrow | Shallow groove in cell surface. Only in animal cells. Actin microfilaments interact with myosin and contract, which pinches the parent cell in two |
| cytokinesis | Division of cytoplasm. Occurs along with telophase. Cleavage furrow pinches cells apart |
| telophase | Cell elongation continues. Daughter nuclei begin to form around chromosomes. Chromatin fiber uncoils. Nucleoli reappear. 2 genetically identical cells formed |
| anaphase | Motor proteins pull chromosomes apart. Attached fibers shorten, non-attached lengthen. Cell elongated as poles move farther apart. Over when chromosomes have reached the poles |
| metaphase | Mitotic spindle fully formed, attaches to centromeres. Chromosomes convene on metaphase plate |
| prophase | Chromatin fibers become tightly coiled and folded. Nucleoli disappear. Sister chromatids appear. Mitotic spindle begins to form from the centrosomes |
| interphase | Growth. Cell synthesizes new molecules and organelles. G1, S, G2. Chromosomes duplicated but still in the form of loosely-packed chromatin. Nucleus has one or more nucleoli |
| mitotic spindle | Chromosome movement depends on it. Football-shaped structure of microtubules that guides the separation of the two sets of daughter chromosomes. Emerges from 2 centrosomes. In centrioles. Microtubule-organizing centers |
| What are the 5 stages of mitosis | Prophase, Prometaphase, Metaphase, Anaphase and Telophase |
| mitosis in evolution | May be solution to problem of allocating identical copies of a large amount of genetic material in a number of separate chromosomes to two daughter cells |
| Cytokinesis | Cytoplasm divided in two |
| Mitosis | Nucleus and its contents divide and are evenly distributed to form two daughter nuclei |
| Mitotic Phase (M Phase) | When cell actually divides. Only about 10% of cell life. Produces two genetically identical daughter cells with single nuclei. Two parts: Mitosis and Cytokinesis |
| G2 | Cell grows more and completes preparation for cell division |
| S | Cell continues to grow and copies its chromosomes |
| G1 | Cell grows |
| mitotic interphase | Most of the cell cycle. Cell roughly doubles everything in its cytoplasm and replicates chromosomal DNA. Metabolic activity of the cell is high. Cell performs its functions for organism. 90% of cell life. 3 subphases: G1, S, G2 |
| what are the who broad stages of the cell cycle | Growing Stage (Interphase). Cell Division State (Mitosis) |
| cell cycle | Ordered sequence of events that extends from the time a cell is first formed until its own division into two cells |
| centromere | Narrow 'waist' between sister chromatids |
| sister chromatids | Two identical copies of a DNA molecule. Once they separate, are called chromosomes |
| how many chromosomes does the human body have | 46 |
| chromatin | Chromosomes exist as diffuse mass of long, thin fibers. Combination of DNA and protein molecules |
| binary fission | How Prokaryotes reproduce. 1 circular DNA molecule w/ single chromosome. 1. Duplicate chromosome and separate copies. 2. Cell elongates and moves copies. 3. Division of daughter cells |
| cell division | How cells reproduce. Can reproduce entire organism or only small part. Enables sexually reproducing organisms to develop from a single cell. Continues to function in renewal and repair |
| how can you develop domestic breeds | Controlled breeding to display particular traits. Attempt to make like beget like more than it would in nature |
| sexual reproduction | Like does not beget like. Resemble parents but not identical. Can produce variation among offspring |
| chromosomes | Structures that contain most of organisms DNA. Each eukaryotic chromosome has 1 long DNA molecule w/ lots of genes and proteins |
| asexual reproduction | "Like begets like" Genetically identical offspring by a single parent. One simple principal of inheritance |
77 cards - created nov 19, 6:22pm