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| 61699697 | mitosis | nuclear division that does not create genetic diversity | |
| 61699698 | gametes | sex cells whose purpose is to fuse with one another (syngamy) | |
| 61699699 | syngamy | the fusion of two gametes, which produces a zygote | |
| 61699700 | zygote | one cell created by the fusion of two gametes | |
| 61699701 | embryo | a multicellular zygote | |
| 61699702 | binary fission | the way in which prokaryotes and bacteria divide when an exact copy of a cell is made, and then the copy and original split | |
| 61699703 | somatic cells | non-sex cells | |
| 61699704 | sister chromatids | copies of DNA before they become chromosomes; they are still bound at the centromere; they have the same alleles and the same genes | |
| 61699705 | histones | protein groups that are present in DNA to help organize it | |
| 61699706 | separate, repair, organize, make mRNA | roles of proteins in DNA | |
| 61699707 | homologous chromosomes | pairs of chromosomes; each one in the pair has the same length, same shape, and same genes in same spot, but can have different alleles | |
| 61699708 | alleles | different forms of the same gene | |
| 61699709 | haploid cells | cells that have one type of chromosome (no homologous pairs) | |
| 61699710 | diploid cells | cells that have two of each type of chromosome (homologous pairs); gives an insurance policy against mutations that can kill you | |
| 61699711 | haploid cells | n | |
| 61699712 | diploid cells | 2n | |
| 61699713 | prophase | chromatin fibers become tightly coiled, nucleoli disappear, each duplicated chromosome appears as two identical sister chromatids joined at their centromeres and along arms, mitotic spindle begins to form, centrosomes move away from each other | |
| 61699714 | metaphase | centrosomes are at opposite poles of cell, chromosomes convene on the metaphase plate, for each chromosome kinetochores of sister chromatids are attached to kinetochore microtubules coming from opposite poles | |
| 61699715 | anaphase | begins when cohesin proteins are cleaved, allowing two sister chromatids of each pair to part suddenly--each chromatid becomes a chromosome; daughter chromosomes move toward opposite ends of cell, cell elongates, two ends of cell are symmetric | |
| 61699716 | telophase | two daughter nuclei form, nuclear envelopes arise from fragments of parent cell, nucleoli reappear, chromosomes decondense | |
| 61699717 | cytokinesis | division of cytoplasm that finalizes the creation of daughter cells; animal cells have cleavage furrow, plant cells have cell plate | |
| 61699718 | cell cycle | the life of a cell from the time it is formed from a dividing parent cell until its own division into two cells | |
| 61699719 | mitosis | the division of the nucleus | |
| 61699720 | meiosis | cell division which yields nonidentical daughter cells that have only one set of chromosomes; only occurs in gametes | |
| 61699721 | mitotic phase | includes both mitosis and cytokinesis; shortest part of cell cycle | |
| 61699722 | interphase | a long phase of the cell cycle that accounts for 90% of the cycle | |
| 61699723 | G1 phase | "first gap" in which the cell grows; lasts 5-6 hours | |
| 61699724 | S phase | "synthesis" in which the cell continues to grow and chromosomes are duplicated; lasts 10-12 hours | |
| 61699725 | G2 phase | "second gap" in which the cell grows and prepares to divide; lasts 4-6 hours | |
| 61699726 | M phase | the cell divides, the cycle repeats (lasts under an hour) | |
| 61699727 | mitotic spindle | a structure that forms within a cell during prophase; consists of fibers made of microtubules and associated proteins; uses microtubules from the cytoskeleton, which partially disassembles before the mitotic spindle is formed; adding subunits of tubulin elongates spindle and taking them away shortens it | |
| 61699728 | centrosome | a sub-cellular region containing material that functions throughout the cell cycle to organize the cell's microtubules | |
| 61699729 | aster | the radial array of short microtubules that extends from the centrosome | |
| 61699730 | kinetochore | a structure of proteins associated with specific sections of chromosomal DNA at the centromere; present in each of two sister chromatids of a replicated chromosome | |
| 61699731 | metaphase plate | the imaginary plate that forms during metaphase at which the centromeres of duplicated chromosomes align | |
| 61699732 | cleavage | the process by which cytokinesis occurs | |
| 61699733 | cleavage furrow | the first sign of cytokinesis in animal cells, which is represented by a shallow groove in the cell surface near the old metaphase plate | |
| 61699734 | cell plate | the sign of cytokinesis in plant cells in which vesicles derived from the Golgi move along microtubules to the center of the cell where they coalesce | |
| 61699735 | origin of replication | a specific place on the bacterial chromosome at which cell division begins | |
| 61699736 | checkpoint | a control point in the cell cycle where stop and go-ahead signals regulate the cycle; signals are transmitted via signal transduction | |
| 61699737 | G0 phase | a nondividing, stalled state that ensues when no go-ahead signal is received by the cell at the G1 checkpoint | |
| 61699738 | cyclin | a protein that has a cyclically fluctuating concentration in the cell to be active | |
| 61699739 | MPF | the activated form of cyclin that triggers prophase of mitosis and phosphorylates other enzymes that catalyze individual steps of prophase | |
| 61699740 | CDKs | enzymes in an inactive form that are present in consistent concentrations over the cell cycle; *most significant enzyme in regulating cell cycle | |
| 61699741 | growth factors | molecules present in the cell cycle that act like hormones in that they cause a chemical change and send chemical signals; necessary for cell division | |
| 61699742 | mutagens | factors that cause mutations | |
| 61699743 | carcinogens | factors that cause cancer | |
| 61699744 | anchorage dependence | the need for a cell to attach itself to something else when dividing; cancer cells lack this | |
| 61699745 | spore | one haploid cell, does not fuse during syngamy, divides by mitosis | |
| 61699746 | sporophyte | the multicellular diploid stage of a plant; makes spores | |
| 61699747 | gametophyte | the multicellular haploid stage of a plant; makes gametes | |
| 61699748 | alternation of generations | demonstrated by the plant life cycle because it alternates from sporophyte (diploid) to gametophyte (haploid) | |
| 61699749 | synapsis | occurs when homologous chromosomes find one another to create a group of four strands of chromatin (known as a tetrad); occurs during prophase I | |
| 61699750 | tetrad | a group of four strands of chromatin that is formed during synapsis in prophase I | |
| 61699751 | crossing over | the exchange of exactly corresponding regions of two homologous chromosomes in a tetrad; causes genetic variation; occurs roughly 2-3 times per tetrad | |
| 61699752 | gametogenesis | the creation of gametes | |
| 61699753 | spermatogenesis | the creation of sperm | |
| 61699754 | oogenesis | the creation of eggs | |
| 61699755 | density-dependent inhibition | a phenomenon in which crowded cells stop dividing; cancer cells lack this | |
| 61699756 | transformation | the sign of abnormal behavior in a normal cell that qualifies it as a cancer cell | |
| 61699757 | benign tumor | a tumor that consists of cells that remain at the original site | |
| 61699758 | malignant tumor | a tumor that consists of cells that become invasive enough to impair organ function | |
| 61699759 | metastasis | occurs when tumor cells can enter blood vessels and travel to other parts of the body to grow | |
| 61699760 | ectopic pregnancy | occurs when the embryo implants itself in the fallopian tube and begins to grow there; the baby will not survive, the mother can be endangered | |
| 61699761 | 1 | number of divisions in mitosis | |
| 61699762 | 2 | number of divisions in meiosis | |
| 61699763 | 2 | number of daughter cells in mitosis | |
| 61699764 | 4 | number of daughter cells in meiosis | |
| 62195361 | nonvascular plants | plants known as bryophytes; classic example is moss | |
| 62195362 | nonvascular plants | plants that typically form in large patches of green on the forest floor, dead logs, or bricks; do not contain xylem or phloem; usually are present only in sporophyte stage | |
| 62195363 | gametangia | the structures in which gametes are made; only present in gametophytes | |
| 62195364 | archegonia | the structures within gametangia that make eggs | |
| 62195365 | artheridia | the structures within gametangia that make sperm | |
| 62195366 | sporangia | the location on a plant at which spores are made; located in the capsule of the diploid sporophyte | |
| 62195367 | vascular plants | plants the evolved second; contain xylem and phloem but lack seeds; classic example is a fern | |
| 62195368 | fronds | fern leaves that grow from the base of the plant, originating in a curled state so that they unravel as they grow | |
| 62195369 | fiddlehead | an immature frond | |
| 62195370 | sori | black or brown structures on the underside of frond leaflets (known as sporangi) that are evidence for spore production | |
| 62195371 | seed plants | plants that evolved third; called gymnosperms | |
| 62195372 | seed plants | plants without fruits or flowers; produce naked seeds because they are not surrounded by fruit; examples include conifers, cycads, and Ginkgo trees | |
| 62195373 | flowering plants | plants that have seeds, vascular tissues, flowers, and fruits; most successful group in kingdom plantae | |
| 62195374 | flowering plants | plants known as angiosperms or anthophytes | |
| 62195375 | stamen | the male structure on a flower that is composed of a stalk and a bulb | |
| 62195376 | filament | the stalk of a stamen | |
| 62195377 | anther | the bulb of a stamen that makes pollen | |
| 62195378 | carpel | the female structure on a flower that is composed of the ovary, ovules, style, and stigma; sometimes called a pistil | |
| 62195379 | style | the stalk that comes from the ovary | |
| 62195380 | stigma | the top of the style on the carpel that receives the pollen | |
| 62410243 | central cell | a cell that contains two haploid nuclei and is present within the ovule of a flowering plant | |
| 62410244 | seven-cell female gametophyte | a structure contained inside each ovule that makes haploid eggs | |
| 62410245 | double fertilization | one sperm fertilizes an egg and the other sperm fertilizes the central cell, which produces endosperm | |
| 62410246 | tube cell | the cell from a male plant that grows down the style to the opening of the micropyle; grows a pollen tube |
