AP Biology Mitosis and Meiosis Flashcards
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| 8801828818 | two | How many daughter cells are produced in mitosis? | 0 | |
| 8801828819 | genome | -consists of all the DNA in a cell -holds specific genetic traits | 1 | |
| 8801828820 | chromosomes | -packages in a cell which contain DNA molecules -humans have 46 -each species has a specific number |  | 2 |
| 8801828821 | chromatin | -makes up chromosomes -complex of DNA and protein |  | 3 |
| 8801828822 | somatic cells | -have two sets of chromosomes -go through mitosis -nonreproductive | 4 | |
| 8801828823 | gametes | -have half as many chromosomes as somatic cells -go through meiosis -reproductive cells | 5 | |
| 8801828824 | sister chromatids | -each duplicated chromosome has two -separate during cell division -should be exactly identical |  | 6 |
| 8801828825 | centromere | -narrow waist of the duplicated chromosome -where the two chromatids are most closely attached |  | 7 |
| 8801828826 | cytokinesis | -division of the cytoplasm | 8 | |
| 8801828827 | interphase | -where 90% of a cell's life is spent -cell growing and chromosomes copying -3 subphases: -G1 -Synthesis (S) -G2 | 9 | |
| 8801828828 | S | In which subphase of interphase are the chromosomes duplicated? | 10 | |
| 8801828829 | prophase | -first stage of mitosis -chromosomes condense -spindle fibers start to form -nuclear envelope starts to break down | 11 | |
| 8801828830 | prometaphase | -second stage of mitosis -the nuclear envelope fragments -the spindle microtubules attach to the kinetochores of the chromosomes |  | 12 |
| 8801828831 | metaphase | -third phase of mitosis -chromosomes line up end to end in the center of the cell -spindle fibers attach to the kinetochores of each sister chromatid |  | 13 |
| 8801828832 | anaphase | -fourth phase of mitosis -sister chromatids separate and move toward opposite ends of the cell |  | 14 |
| 8801828833 | telophase | -fifth and final stage of mitosis -genetically identical daughter nuclei form at opposite ends of the cell -nonkinetochore microtubules from opposite poles overlap and push each other elongating the cell |  | 15 |
| 8801828834 | mitotic spindle | -apparatus of microtubules that control chromosome movement during mitosis |  | 16 |
| 8801828835 | centrosome/centrioles | -microtubule organizing center -replicates, each set goes to opposite ends -spindle fibers grow out from them |  | 17 |
| 8801828836 | kinetochores | -protein complexes that assemble on sections of DNA at centromeres -where spindle fibers and microtubules attach |  | 18 |
| 8801828837 | metaphase plate | -midway point between the spindles two poles -where chromosomes line up in metaphase |  | 19 |
| 8801828838 | cleavage furrow | -formed during late telophase and cytokinesis in animal cells |  | 20 |
| 8801828839 | cell plate | forms in plant cells during cytokinesis |  | 21 |
| 8801828840 | binary fission | -prokaryotic method of reproduction and cell division -chromosome replicates and the two daughter chromosomes actively more apart |  | 22 |
| 8801828841 | cell cycle control system | -directs sequential event of the cell cycle -regulated by internal and external force -receives signals from the cytoplasm |  | 23 |
| 8801828842 | checkpoints | -where the cell cycle stops until a go-ahead signal is received |  | 24 |
| 8801828843 | G0 | -the nondividing stage of the cell if it does not pass the G1 checkpoint | 25 | |
| 8801828844 | growth factors | proteins released by certain cells that stimulate other cells to divide, one of the most well-studied is Platelet-derived growth factor (PDGF) | 26 | |
| 8801828845 | density dependent inhibition | crowded cells stop dividing | 27 | |
| 8801828846 | cancer cells | -cells that exhibit neither density dependent inhibition nor anchorage dependence -escape the usual control system -do not need growth factors to divide | 28 | |
| 8801828847 | tumors | -masses of abnormal cells within otherwise normal tissue -formed by cancer cells | 29 | |
| 8801828848 | benign tumor | -lump of abnormal cells remaining only at the original site of the cancer | 30 | |
| 8801828849 | malignant tumor | invade surrounding tissue | 31 | |
| 8801828850 | metastasize | exporting cancer cells to other parts of the body, where they may form secondary tumors | 32 | |
| 8801828851 | 46 | What is the chromosome number for humans? | 33 | |
| 8801828852 | homologous chromosomes | -2 chromosomes in each pair(one from mom, one from dad) -same length and shape -carry genes controlling the same inherited characters, but may have different alleles (versions of the gene), so not exactly idenitical |  | 34 |
| 8801828853 | diploid cell | -has two sets of chromosomes -human # is 46 -2n |  | 35 |
| 8801828854 | haploid | -gamete -contains a single set of chromosomes -n | 36 | |
| 8801828855 | fertilization | the union of gametes (sperm and egg) | 37 | |
| 8801828856 | zygote | -fertilized egg -one set of chromosomes from each parent -diploid cell produces somatic cells by mitosis | 38 | |
| 8801828857 | prophase I | -stage of meiosis -occupies more than 90% of the time required for meiosis -chromosomes condense -tetrads form, synapse and crossing over | 39 | |
| 8801828858 | synapsis | -homologous chromosomes loosely pair up in meiosis -align gene by gene -get together with homologous pair | 40 | |
| 8801828859 | crossing over | nonsister chromatids exchange DNA segments in meiosis |  | 41 |
| 8801828860 | metaphase I | -stage of meiosis -homologous pairs line up side by side in the middle of the cell and the spindle fibers attach to them |  | 42 |
| 8801828861 | anaphase I | -stage of meiosis -chromosomes move toward each pole -sister chromatids move as one unit toward the pole (centromere does not split) |  | 43 |
| 8801828862 | telophase I | -stage of meiosis -beginning: each half of the cell has a haploid set of chromosomes -each chromosome consists of two sister chromatids |  | 44 |
| 8801828863 | prophase II | -stage of meiosis -spindle apparatus forms |  | 45 |
| 8801828864 | metaphase II | -stage of meiosis -chromosomes line up end to end at metaphase plate -kinetochores of sister chromosomes attach to microtubules extending from opposite poles |  | 46 |
| 8801828865 | anaphase II | -stage of meiosis -sister chromatids of each chromosome move as two newly individual chromosomes toward opposite poles |  | 47 |
| 8801828866 | telophase II | -stage of meiosis -chromosomes arrive at opposite poles -nuclei form and the chromosomes begin decondensing |  | 48 |
| 8801828867 | independent assortment of chromosomes | -mechanism contributing to genetic variation -homologous pairs of chromosomes orient randomly -metaphase I -each pair of chromosomes sorts maternal and paternal homologs into daughter cells independently of the other pairs -the number of combinations possible when chromosomes assort independently into gametes is 2^n where n is the haploid number |  | 49 |
| 8801828868 | crossing over | -mechanism contributing to genetic variation -produces recombinant chromosomes -begins in early prophase I -homologous chromosomes pair up gene by gene -homologue portions of two nonsister chromatids trade places -combines DNA from two parents into a single chromosome |  | 50 |
| 8801828869 | random fertilization | -any sperm can fuse with any ovum -the fusion of two gametes produces a zygote with any of about 70 trillion diploid combinations -each zygote has a unique genetic identity |  | 51 |
| 8801828870 | Cyclin-Dependent Protein Kinases | Through phosphorylation, signal the cell that it is ready to pass into the next stage of the cell cycle. As their name suggests, dependent on cyclins, another class of regulatory proteins. Cyclins bind to Cdks, activating the Cdks to phosphorylate other molecules. | 52 | |
| 8801828871 | p53 | A protein that senses DNA damage and can halt progression of the cell cycle in G1 (by blocking the activity of Cdk2). Is considered a tumor suppressor gene. Also a key player in apoptosis, forcing "bad" cells to commit suicide. So if the cell has only mutant versions of the protein, it can live on — perhaps developing into a cancer. More than half of all human cancers do, in fact, harbor p53 mutations and have no functioning p53 protein. | 53 | |
| 8801828872 | Proto-oncogene | The genes that code for positive cell cycle regulators. Proto-oncogenes are normal genes that, when mutated in certain ways, become oncogenes: genes that cause a cell to become cancerous. | 54 | |
| 8801828873 | G1 checkpoint | checks for cell size, enough nutrients, growth factors | 55 | |
| 8801828874 | G2/M checkpoint | check for cell size, proper DNA replication | 56 | |
| 8801828875 | spindle checkpoint | check for chromosome attachment to spindle | 57 | |
| 8801828876 | nondisjunction | when chromosomes in meiosis do not separate properly in anaphase I or anaphase II, leading to gametes that have too few or too many chromosomes | 58 |