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53 Cards in this Set
- Front
- Back
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What is the order of the cell cycle? |
Interphase: G1, S, G2 --> Mitosis: (PMATC): Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
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What is the end product of the cell cycle? |
two diploid cells (2n) |
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What two phases does the cell cycle include? |
Interphase and Mitosis |
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What is the purpose of the cell cycle? |
cell growth, cell repair, cell replacement |
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What happens in G1? |
The cell grows in size, makes more cytoplasm, more copies of organelles
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What happens in S phase?
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DNA replicates to make copies of each chromosome
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What happens in G2 phase?
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The cell prepares itself to divide
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When does DNA replication occur and what is it?
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-occurs in S stage of Interphase
-DNA is untwisted so there are two template strands for and new DNA is built |
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What happens with Chromosomes during S phase? |
Chromosomes are replicated so there are two sister chromatids; centromere attaches in center and attaches to spindle in mitosis -tips are telomeres |
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show the diagram of the singular thing |
-top = telomere
-middle = centromere -bottom = telomere |
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show the diagram of the double thing |
-top: telomere
-middle: centromere -both of them together are called sister chromatids -bottom: telomere -still one chromosome -beams coming out of middle thing (kinetochore) = spindle microtubules |
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How many phases of mitosis are there? |
Five: PMATc: Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
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What happens in Prophase?
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Prophase: chromosomes condense and are visible; spindle forms (structure that pulls apart chromosomes)
-you can see individual chromosomes |
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What happens in Metaphase? |
Metaphase: Chromosomes line up in center of spindle -you see this like line and then things coming out from top and bottom |
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What happens in Anaphase? |
Anaphase: spindle pulls chromosomes towards poles of cell
-now there are 2 strings and they're pulling apart but trying to hold on but they're not like attached |
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What happens in Telophase?
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Telophase: nuclear membranes form around the chromosomes and the spindle disappears
-now they're @ complete opposite ends of cell |
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What happens in Cytokinesis? |
Cytokinesis: two cells split completely -they're super unattached and you don't see the chromosomes at all... the two cells are like the size of one of the original cells |
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Where do the three check points occur? |
During G1, between G1 and mitosis, during metaphase of mitosis
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What does the check point at G1 do?
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checks if this is the right time for the cell to divide (if it's ready) if not it goes into a resting point until better time |
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What does the checkpoint between G2 and mitosis check for?
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checks for any DNA mutations: if there are mutations, cell may get destroyed
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What does the checkpoint at metaphase of mitosis do?
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checks that all chromosomes are attached to spindle of cell properly so they can be pulled apart; if not, goes not apoptosis where it's ingested by the enzymes in the cell
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Who asks during check points? |
Tumor suppressor genes and proto-oncogenes?
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What do the check point checker genes do?
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-Tumor suppressor genes send cells to apoptosis if they are mutated, if the t.s. genes are mutated themselves, then the cells continue to divide and then there are many mutated cells; -Proto-oncogenes maintain the speed of the cells; if they're mutated, then the cells divide too quickly and too often |
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Explain the relationship between telomeres and cancer. |
Telomerase is an enzyme that builds telomeres; telomeres should naturally shorten bc every time the DNA replicates it loses some bases, but HLacks' cancer cells were immortal bc telomeres just kept rebuilding (mutation in hTERT --> overproduction of telomerase)
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What is Meiosis? |
cell division associated with sexual reproduction
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What is the end product of meiosis?
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gametes = haploid (n) -half # of chromosomes that's normal for species -humans have 46 total, gametes have 23 chromosomes |
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What is crossing over and when does it occur? |
Crossing over occurs during Prophase 1 and Metaphase 1 and it involves homologous chromosomes crossing over + exchanging pieces -daughter cells: one gamete has all blue chromosome and one gamete has one red; --> unique mix of genes |
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What happens in prophase 1? |
chromosomes become visible and form tetrads |
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What happens in metaphase 1? |
tetrads line up along equator
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What happens in anaphase 1? |
homologous pairs separate
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What happens in telophase 1? |
nuclear membrane reforms around chromosomes
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What happens in cytokinesis 1? |
two cells separate and proceed to meiosis II
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What happens in prophase II? |
spindle reforms
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What happens in metaphase II? |
sister chromatids line up @ equator
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What happens in anaphase II? |
sister chromatids are pulled apart
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What happens in telophase II? |
nuclear membrane reforms and cell pinches in middle
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What happens in cytokinesis II? |
4 unique haploid cells can become mature gametes |
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What are the differences between Mitosis and Meiosis in DNA replication? |
Mitosis: occrs during interphase before nuclear division begins Meiosis: DNA replication doesn't happen until meiosis II begins |
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mitosis vs meiosis: # of divisions |
mitosis: one meiosis: two |
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mitosis vs meiosis: synapsis of homologous chromosomes |
mitosis: doesn't occur meiosis: during prophase I, homologous chromosomes form tetrads... associated w crossing over between nonsister chromatids |
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What are the inheritance of traits controlled by? |
Pair of alleles |
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What are alleles? |
Different versions of genes |
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What is the law of segregation? |
alleles inherit in pairs, they separate from each other into diff gametes during meiosis --> one allele in half, other allele in other half |
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What is the law of independent assortment? |
inheritance of one trait doesn't affect the other (wrinkled stem shape doesn't affect round seed shape bc separate pairs of non-homo chromosomes) |
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What are linked genes? |
Genes near each other on same chromosome are inherited together -fruit fly genes for body color + wing size = near each other on same chromosome; fruit fly w black body will probably have digit wings; gray body = long wings |
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What is co-dominance? |
when both alleles are dominant and fully expressed it's like black feathers and white feathers are co-dominant to each other so WW x BB = BW which are either completely black or completely white for each feather... diff phenotype than either parent |
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What is incomplete dominance? |
when neither allele is completely dominant over the other allele, both are expressed -there's a blended phenotype -red flowers x white flowers = pink flowers |
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What is polygenic inheritance? |
When more than one gene controls a trait (environment affects height) |
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What is an STR? |
Short tandem repeat - used for paternity and crime cases |
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What are the two techniques for STRs? |
gel electrophoresis and polymerase chain reaction (PCR) |
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Where are STR's found? |
in between genes |
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What are the steps of STR? |
1. get a DNA sample 2. make millions of copies of specific dna sequences ________gel electrophoresis time________ 3. separate peices of DNA 4. visualize data 5. analyze the data |
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How does PCR work? |
so you get like 1-2 cells and then the thermocycler heats up the DNA strands and then the taq polymerase attaches and builds new DNA strands and you get a bunch of DNA strands and then you separate them by length and yo use electricity to push DNA through the cell and then you visualize the data with xray film and then analyze it |
