Complete List of Terms and Definitions for Cell cycle/reproduction

Terms Definitions
gametes sex cells
somatic cells body cells
carcinogenesis development of cancer
apoptosis programmed cell death
prophase chromatin condense, chromosomes visible
genome a cell's genetic information
carcinogens things that cause cancer
leukemia cancer of blood forming cell
kinetochore specialized protein structure located at the centromere. each of the two chromatids of a chromosome gets one in prometaphase
chiasmata criss-crossed regions where crossing over has occurred
zygote diploid cell resulting from fertilization
S stage DNA replication occurs, each chromosome is composed of two identical DNA double helix
angiogenesis the formation of new blood vessels
prometaphase preparations for sister chromatid are evident, kinetochores appear on each side of the centromere, and these attach sister chromatids to the so-called kinetochore spindle fibers. these fibers extend from the poles to the chromosomes, (soon to be located at the center of the spindle)
M stage mitotic stage, daughter chromosomes are distributed to two daughter nuclei. when division of the cytoplasm is complete, two daughter cells are present
histone a simple protein containing mainly basic amino acids, globular protein molecule around which DNA is tightly coiled in chromatin
centromere specialized region where the two sister chromatids are most closely attached
recombinant chromosomes individual chromosomes that carry genes derived from two different parents. produced by crossing over
crossing over genetic rearrangement between sister chromatids
chromatin eukaryotic chromosomes are made of this complex of DNA and associated protein molecules
mitogens growth factors that promote mitosis. an example is platelet-derived growth factor, which is required for the division of fibroblasts
chromosomes DNA molecules are packaged into these
sister chromatids Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II.
high-energy radiation used to treat localized tumors. damages DNA in cancer cells because they have lost the ability to repair such damage
carcinomas cancers that form in the epithelial cells
cytokinesis the division of the cytoplasm. usually well underway by late telophase. in animal cells, involves formation of a cleavage furrow.
oncogenes cells involved in cell division in growth. mutations in THESE can lead to cancer. like a stuck brake pedal
metaphase II the chromosomes are positioned along the metaphase plate. because of crossing over in meiosis I, chromatids of each chromosome are not genetically identical. the kinetochores of sister chromatids are attached to microtubules extending from opposite poles
metaphase I the pairs of homologous chromosomes, in the form of tetrads, are now arranged on the metaphase plate. both chromatids of a homologue are attached to kinetochore microtubules from the poles
mitotic spindle begins to form during prophase. consists of fibers made of microtubules and associated proteins. includes the centrosomes, the spindle microtubules, and the asters
cell plate produced during telophase in plant cells. plants have no cell walls, so no cleavage furrow. vesicles from the Golgi move along microtubules to the middle of the cell, where THIS is produced. cell wall materials collect here, and THIS enlarges until its surrounding membrane fuses with the plasma membrane along the perimeter of the cell, resulting in two daughter cells.
G2 stage stage from DNA replication to mitosis. Cell synthesizes proteins that will aid cell cell division
reproductive cloning The process of implanting an early embryo into the uterus of a surrogate mother. The resulting animal will be genetically identical to the donor of the nucleus
binary fission a form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size
therapeutic cloning process where a cloned embryo is generated via somatic cell nuclear transfer that can be used to generate new tissue or organs
telomeres Repeated DNA sequences at the ends of eukaryotic chromosomes
interphase of meiosis chromosomes replicate during S phase. each replicated chromosome consists of two genetically identical sister chromatids connected at the centromere. the centrosome replicates, forming two centrosomes.
prophase II a spindle apparatus forms. late in THIS STAGE, chromosomes move toward the metaphase II plate
telophase I and cytokinesis occur simultaneously. at the beginning, each half of the cell has a complete haploid set of chromosomes, but each chromosome is still composed of two sister chromatids. a cleavage furror forms. the chromosomes decondense and the nuclear envelope and nucleoli reform.
density-dependent inhibition crowded cells stop dividing. when a cell population reaches a certain density, the availability of nutrients becomes insufficient for continued growth
cyclin-dependent kinases Cdks. kinases that regulate the cell cycle and must be attached to a cyclin to be active
origin of replication cell division in prokaryotes begins when the DNA of the bacterial chromosome replicates HERE
cyclin must be attached to a kinase that regulates the cell cycle for the kinase to be active. gets its name from its fluctuating concentration in the cell
benign tumor when a mass of transformed cells remains at the original site
anaphase shortest stage of mitosis, takes a few minutes. two sister chromatids of each pair split. each chromatid is now a chromosome. the chromosomes begin moving toward opposite end of the cell, as their kinetochore microtubules shorten. the cell elongates as the nonkinetochore microtubules lengthen.
cell cycle orderly set of stages that take place between the time a eukaryotic cell divides and the time the resulting daughter cells also divide
nucleoid A dense region of DNA in a prokaryotic cell
asexual reproduction one organism is the sole parent, and gives rise to a clone
origins of genetic variation among offspring independent assortment of chromosomes, crossing over, random fertilization
anchorage dependence to divide, cells must be attached to a substratum
three events unique to meiosis I synapsis/crossing over, tetrads on the metaphase plate, separation of homologues
prophase I takes up more than 90% of the time for meiosis. chromosomes begin to condense. homologous chromosomes loosely pair along their lengths. crossing over and synapsis occur. late in THIS STAGE, the kinetochores of each homologue attach to microtubules from one pole and then move toward the metaphase plate