Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Bio Unit 5
| Question | Answer |
|---|---|
| Pros of asexual reproduction | no need for partner; less mutation; faster; requires less energy |
| cons of asexual reproduction | no genetic variability; not able to adapt, therefore can go extinct easily |
| cells in multicellular organisms that reproduce asexually | skin cells; red blood cells |
| cells in multicellular organisms that do not reproduce | nerve cells (neurons); hearts muscle cells. research is going on the regenerate these |
| chromatin | fine strands of DNA in protein; when cells is NOT dividing; easier to read |
| chromosome | condensed DNA; when cell is dividing; easier to separate |
| chromatid | two identical DNA's |
| binary fission | single chromosome replicates; each copy moves to opposites sides; cell elongates; when 2X original size membrane pinches; cell wall deposited; two identical cells produced |
| phases of cell cycle | Interphase (G1, S, G2) mitosis (M phase) |
| what does cell do in interphase? | does "cell job", 90% of time is spent in interphase, DNA found in chromatin form |
| G1 | cell is growing to normal size; protein production and high metabolism |
| S | DNA replication; "point of no return"; chromosomes consist of 2 chromatids |
| G2 | preparation for division; replication of centrioles in animal cells |
| kinetochore | attachment site for spindle fiber on chromosome |
| centrosome | where spindle fibers originate |
| mitosis | nuclear division; requires all cells energy and resources, last step is cytokinesis |
| prophase | chromatin turns to chromosomes; the nuclear envelope breaks up; spindle fibers unwind |
| prometaphase | nuclear envelope is gone; spindle fibers are out |
| microtubules' role in mitosis | they are the spindle fibers; they are taken away form the cytoskeleton, making the cell more flexible |
| metaphase | chromosomes lined in the middle, centrosomes on either pole |
| anaphase | chromatids are pulled apart, spindle fibers breaking |
| telophase and cytokinesis | nucleolus forming; nuclear envelope forming; chromatin forms; spindle fibers back to cytoskeleton |
| enzyme used in anaphase | separase |
| cytokinesis in animal cells | cleavage furrow forms; microfilaments (actin filaments) are used |
| cytokinesis in plant cells | cell plate made out of cellulose forms in middle of cell |
| problems if the cell cycle is out of control | not doing cell job; taking up space and nutrients, depriving other cells; greater chance of mutation |
| the three major checkpoints if cell cycle | 1)G1 checkpoint 2)G2 checkpoint 3) M Checkpoint |
| G1 checkpoint | nutrients, growth factors; does it need to divide; density-dependent inhibition, anchorage dependence |
| G2 checkpoint | was DNA replicated properly |
| M checkpoint | checks metaphase before going into anaphase |
| enzymes that regulate checkpoints | cyclin-dependent kinases (CDKs), activated when bound to proteins called cyclins, together they are a form of alosteric regulation |
| most important checkpoint | G1. if there is no signal, cells exits cell cycle to G0 |
| types of external signals | growth factors; density-dependent inhibition; anchorage dependence |
| growth factors | proteins released by cells stimulate other cells to divide; cells stop dividing when growth factor is depleted; ex. erythrpoetin(EPO. stimulates red blood cell production to carry more oxygen) and interleukin |
| density dependent inhibition | results from crowded conditions, when one cell touches another, cell division stops ex. skin cells. out of control = wart |
| anchorage dependence | must be in contact with a solid surface to divide |
| cell cycle out of control= | cancer. do not respond to normal cell cycle controls ex. apoptosis |
| carcinoma | originate in linings or coverings. ex. skin or linings of digestive tract |
| sarcoma | originate in support tissues. ex. bone and muscle |
| lymphoma/ leukemia | originate in blood-forming tissues. ex. bone marrow, spleen, lymph nodes |
| tumor | mass of abnormal cells |
| benign tumor | mass remains in original site |
| malignant tumor | mass spreads to other parts of the body |
| metastasis | separation of cancer cells from tumor; travel through the circulatory system |
| somatic cells | diploid (homologous pairs); 2n=46; 44 autosomes, 2 sex chromosomes |
| homologue | chromosome making up a homologous pair |
| locus | location of gene on the chromosome |
| describe meiosis | cell division that occurs to produce gametes, DNA replicated once, cell divides twice; produces 4 cells with 1/2 the original chromosomes |
| prophase I | homologous pairs forms tetrads |
| chiasmata | what holds tetrads together |
| anaphase I | homologous pairs split |
| anaphase II | chromatids split |
| nondisjunction | failure of chromosomes to separate properly in meiosis |
| result of nondisjunction in meiosis I | a tetrad doesn't split, creating 2 gametes with an extra chromosome and 2 gametes lacking a chromosome |
| result of nondisjuction in meiosis II | chromatids do not split up, 1 gamete with an extra chromosome and 1 gamete lacking a chromosome |
| aneuploidy | abnormal number of chromosomes |
| crossing over | further increases genetic variability, occurs in prophase 1 when tetrads are forming, known as CHIASMA, errors called chromosomal variations |
| charge of DNA | negative, phosphate groups |
| proteins that wrap around DNA | histones |
| genome | all of organism's DNA, provides working instructions for cell through protein |
| Griffith | 1928, determined that pathogenicity could be transferred when non-living organisms were exposed to remains of dead pathogens (transformation); used 2 types of bacteria(smooth or rough) and injected into mouse |
| Avery | 1944; identified "transforming substance" as DNA , no one believed him |
| Hershey and Chase | 1952; used virus with labeled phosphorus and sulfur (phosphate in DNA and sulfur in protein systine) proved that DNA component was injected into cells |
| Rosalind Franklin | produced x-ray crystallography images of DNA, these were used by watson and crick without permission |
| Watson and Crick | discovered that DNA was a double helix; backbone was alternating sugar phophate molecules, interior made of N-bases |
| chargraff | chemically proved the same base-pairing rules that watson and crick proved structurally |
| monomers of DNA | nucleotides |
| pyrimidines | 5 ring, thymine and cytosine |
| purines | 5 and 6 ring, adenine and guanine |
| structure of DNA | nucleotide strands are antiparallel; 3' or 5'; PHosphate Five' and hydroxyl 3' |
| nitrogen bases held together with what bonds? | hydrogen; A-T has to (tattoo) and C-G has 3(harder to break) |
| covalent bond in sugar-phosphate backbone of DNA | phosphodiesterlinkage |
| semi-conservative replication | 1 old strand, 1 new strand |
| meselson-stahl experiment | two different labeled nitrogens in DNA; centrifuged after both replications |
| DNA helicase | enzyme; unwinds the DNA double helix |
| origins of replication | specific points on the DNA molecule where replication begins; many in linear DNA; only one in bacterial or circular DNA |
| replications forks | Y-shaped region where new strands of DNA are elongating |
| what keeps the DNA from hydrogen bonding back together after it is taken apart? | single-strand binding proteins |
| topoisomerase | relieves tension created by unwinding of DNA by making cuts, untwisting, and rejoining the nucleotide strand |
| DNA polymerase | adds nucleotides, proofreads, and removes RNA primers |
| two limitations of DNA polymerase | only adds 5' to 3' ; can only add to an existing strand |
| enzyme that adds RNA primers | primase |
| direction in which DNA is "read" by DNA polymerase | 3'-5' |
| side that is replicated as a continuous strand | leading strand |
| lagging strand | strand that cannot be replicated in continuous strand because the whole strand is not unzipped for it to be synthesized 5' to 3' |
| Okazaki fragments | short pieces of DNA on lagging strand |
| DNA ligase | binds fragments together to form a continuous strand of nucleotides |
| why does DNA get shorter every time it replicates? | because DNSA is linear, DNA polymerase cannot go back to replace RNA primer, cell chops it off because it doesnt recognize it as DNA |
| telomeres | protect genetic information in chromosomes, telomeres cut off instead of chromosomes |
| what happens when the telomere is used up? | cell dies, AGING |
| telomerase | enzyme produced by stem cells and cancer cells that restore telomeres, fountain of youth? |
Created by:
bootoo
Popular Biology sets