Cell Division, Cancer Quest – Flashcards

development growth- zygote, embryo, fetus, baby/child, adolescence, adult

regeneration/repair of damaged tissue-skin wound healing (burns, cuts, scapes of skin or endothelial cells (line of GI tract) creation of new blood cells -growth (in multicellular organisms, cells become less efficient if hey are too big)

prokaryotes/bacteria, some protists, some plants, hydras binary fission- chromosome replication-one copy of the origin, replication continues one copy of the origin is now at each end of cell, replication finishes the plasma membrane grows inward and new cells wall is deposited, two daughter cells result (clones) in prokaryotes, chromosome= a circle of DNA

sperm + egg (created by testes and ovary cells) meiosis creates gametes (sex cells) with half # of chromosomes of body cells

maintain a small SA/vol ratio for efficient transport in/out of cell and access to DNA info

binary fission- chromosome replication-one copy of the origin, replication continues one copy of the origin is now at each end of cell, replication finishes the plasma membrane grows inward and new cells wall is deposited, two daughter cells result (clones) -only copies one chromosome -does not need to duplicate all other organelles

chromatin: material made of DNA wrapped around histone proteins and then supercoiled chromosome: organized structure made of chromatin (linear pieces of DNA in eukaryotic) DNA is loosely packed during active use (interphase) --easier to use/read DNA is condensed during Cell division --easier to duplicate and move, separate

interphase (G1,S,G2) 90% of cell cycle -g1 (gap 1): cell growth and normal metabolism; organelles are duplicated prior to S phase -s (synthesis): DNA replication takes place; all individual chromosomes become duplicated chromosomes -g2 (gap 2): further cell growth; duplicated DNA is checked for errors, which are corrected as needed; cell makes final preparations for division (make spindle proteins) mitosis (division of nucleus, prophase, metaphase, anaphase, telophase) prophase: early mitotic spindle, cytokinesis: division of cytoplasm plants: during telophase, vesicles containing cell wall material collect at the middle of the parent cell. the vesicles fuse, forming a membranous cell plate. the cell plate grows outward, accumulating more cell wall materials as more vesicles fuse with it. eventually, the outer edges of the cell plate fuse with the plasma membrane and the cell plates contents join the parent cell wall. animals: cytokinesis occurs by a process known as cleavage, the first sign is appearance of cleavage furrow, the furrow continues and eventually pinches the parent cell in two

the cell cycle is regulated through G1, G2, and metaphase checkpoints G1: cell size is adequate, nutrient availability is sufficient, growth factors (signals from other cells) are present G2: cell size is adequate, chromosome replication is successfully completed Metaphase: all chromosomes are attached to mitotic spindle in order to divide, cells need: growth factor proteins (a "go" signal), a surface to attach to, space, nutrients, oxygen, to be big enough, to be "healthy" (no DNA mutations) adequate space (density-dependence): need low densities to ensure access to nutrients and growth factors, thus will not divide at high densities anchorage dependence: need to attach to a surface to grow and divide when regulation of cell cycle fails= cancer

(tumors are abnormal masses of cells) benign: abnormal growth of a mutated cell that stops/does not spread beyond local area (usually harmless) malignant/cancerous: abnormal growth of a mutated cell that does not stop growing and can invade other tissue (beyond local area)

cells from primary (original) tumor spread from the origin to a new tissue/organ, and establish secondary tumor(s). cells can travel far very quickly through a blood vessel or a lymph vessel. a few tumor cells can enter the blood and lymph vessels of the circulatory system and then move to other parts of the body where they may proliferate and form new tumors cancer cells are able to recruit new blood vessels (allows for it to gain nutrients and growth)--characteristic of cancer cells: angiogenesis (vessel creation)

-mutation that stops apoptosis of damaged cells -mutation that helps create/recruit blood vessels (helps angiogenesis) -mutation that slows or stops "tumor suppression" genes -mutation which slows or destroys a protein which normally fixes DNA mutations -mutation that "turns on" growth factors permanently and keeps cells dividing

-carcinogens (chemicals that are known to cause cancer): asbestos, lead/heavy metals, tobacco compounds, BPA (from some plastics), coal -radiation: UV light (from sun, tanning beds, etc), microwaves, Xrays, radioactive materials (research labs, nuclear power plants) -viruses: HPV (human papilloma virus), can lead to cervical and ovarian cancer -heredity (inherited genes with mutations) -increased age -obesity -lack of physical activity -poor diet (lack of fiber and antioxidant-rich food)

traditional: chemotherapy- drugs that stop/kill dividing cells, useful for cancer that has metastasized, since drugs go throughout body. since cancer cells divide more reapidly than most normal cells, they are especially affected by these drugs. some normal cells that also divide fairly rapidly are also affected: bone marrow, lining of digestive tract, skin (including hair follicles)--side affects include low production of blood cells, nausea, sensitivity to UV light and hair loss surgery- physical removal of cancerous tissue, most effective with smaller tumors with clear borders/margins (that have not metastasized), may be preceded or followed by chemotherapy or radiation radiation therapy- involves killing cancer cells with penetrating beams of high energy radiation (requires beam ot be very specifically aimed at tumor cells, in low doses raditaition may cause mutations tha cause a cell to become cancerous, in high doses this radiation is lethal to all cells, radiation therapy can be used alone or in conjunction with surgery and/or chemotherapy) biological/immunotherapy hormone therapy newer/developing: anti-angiogenic drugs prevent the growth of new blood cells, effectively stopping growth of and killing tumors gene therapy

a display of micrographs of the metaphase chromosomes of a cell, arranged by size and centromere position. they are digitally created in order to get rid of other duplicate and can show the banding of the chromosomes. they can also show any abnormalities of the chromosomes

a somatic cell has 46 total individual chromosomes (2 sets) a gamete has 23 total individual chromosomes (1 set)

the purpose of meiotic cell division in eukaryotic organisms is to create gametes for sexual reproduction

recombinant DNA generated by crossover in Prophase I: homologous chromosomes pair up and exchange homologous pieces of DNA. creates new combinations of a persons genes in their gametes, these new combinations are passed on to offspring independent (random) alignment of homologous chromosomes during metaphase I: duplicated chromosomes line up alone not homologous pairs, different arrangements create different chromosome combinations in the gametes produced

sperm and egg formation by meiosis are not identical. sperm: for from testes cells, are evenly divided--creating four even haploid cells egg: form from ovary cells, cytoplasm is not evenly split, only forms 1 egg, forms 3 polar bodies

mitosis: produces 2 diploid cells identical to parent cell and to each other, involves 1 cell division, produces 2 daughter cells, sister chromatids separate (in anaphase), individual chromosomes line up in the middle of the cell, no crossing over occurs, produces body cells (somates) for growth and tissue repair meiosis: produces four haploid cells unlike parent cell and unlike each other, involves 2 cell divisions, produces 4 daughter cells, homologous chromosomes pair and then separate (in anaphase 1) sister chromatids separate in anaphase 2 only, tetrad structure line up in the middle of the cell, crossing over occurs between homologous chromosomes in prophase 1, produces cells for sexual reproduction (gametes)

organized structure made of chromatin , in prokaryotes= a circle of DNA, in eukaryotes- linear pieces of DNA

two identical parts of a duplicated chromosome in a eukaryotic cell

the region of a duplicated chromosome where two sister chromatids are joined and where spindle microtubules attach during mitosis and meiosis. the centromere divides at the onset of anaphase during mitosis and anaphase 2 during meiosis

Spindle fibers form a protein structure that divides the genetic material in a cell. The spindle is necessary to equally divide the chromosomes in a parental cell into two daughter cells during both types of nuclear division: mitosis and meiosis.

material made of DNA wrapped around histone protein then supercoiled

a small protein molecule associated with DNA and important in DNA packing in the eukaryotic chromosome

a double helix (as of DNA) that has undergone additional twisting in the same direction as or in the opposite direction from the turns in the original helix

centrosome: material in the cytoplasm of a eukaryotic cell that gives rise to microtubules; important in mitosis and meiosis, also called microtubule-organizing center centrioles: a structure in an animal cell composed of cylinders of microtubule triplets arranged in a 9 and 0 pattern. an animal usuallly has a centrosome with a pair of centrioles involved in cell division

the first sign of cytokinesis during cell division in an animal cell; a shallow groove in the cell surface near the old metaphase plate

a double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis

a protein secreted by certain body cells that stimulates other cells to divide

abnormal masses of cells

abnormal growth of a mutated cell that stops/ does not spread beyond local area (usually harmless)

abnormal growth of a mutated cell that does not stop growing, and can invade other tissue beyond local area

the spread of cancer cells beyond their original site

chemicals that are known to cause cancer

(vessel creation) creation of new blood cells, a characteristic of cancer cells

chromosomes that carry genes that code for the same types of traits (ex. eye color, hair color)

homologous chromosomes pair up and exchange homologous pieces of DNA in prophase I

the recombined DNA molecule formed by crossover

(2N) having two sets of chromosomes (ex. somatic cells-body cells)

(N) cells have a set of chromosomes (ex. gamete)

body cell- has 46 chromosomes

a sex cell (egg or sperm)

the fertilized egg, which is dilpoid, that results from the union of a sperm cell and an egg cell

a display of micrographs of the metaphase chromosomes of a cell, arranged by size and centromere position. they are digitally created in order to get rid of other duplicate and can show the banding of the chromosomes. they can also show any abnormalities of the chromosomes

the rest of the chromosomes besides the sex chromosomes

genes determining gender

an accident of meoisis or mitosis in which a pair of homologous chromosomes or a pair of sister chromatids fail to separate at anaphase

the female gonad, which produces egg cells and reproductive organs

(egg cell) the female gametes, the haploid, unfertilizied egg

each of the small cells that bud off from an oocyte at the two meiotic divisions and do not develop into ova.

the male gonad, produces sperm

a male gamete

meiotic nondisjunction- an accident of meoisis or mitosis in which a pair of homologous chromosomes or a pair of sister chromatids fail to separate at anaphase

deletions- the loss of one or more nucleotides from a gene by mutation; the loss of a fragment of a chromosome duplication- repetition of part of a chromosome resulting from fusion with a fragment from a homologous chromosome; can result from an error in meiosis or from mutagenesis inversions-a change in a chromosome resulting from reattachment of a chromosome fragment to the original chromosome, but in a reverse direction translocation-a change in a chromosome resulting from a chromosomal fragment attaching to a nonhomologous chromosome can occur as a result of an error in meiosis

down syndrome: 3 copies of chromosome 21 *autosomes not sex cells Turner's syndrome: female, does not have 2nd x chromsome, has 4 (XO) Klinefelter's syndrome: male, has 2 x and 1 y, person has 47 chromosomes (XXY) Triple X: extra X chromosome in females (XXX) trisomy: a condition in which an extra copy of a chromosome is present in the cell nuclei, causing developmental abnormalities. monosomy: the condition of having a diploid chromosome complement in which one (usually the X) chromosome lacks its homologous partner.