Term
| What occurs in prokaryotic cells when the DNA has been copied? |
|
Definition
|
|
Term
| How does the cell divide? What does this ensure? |
|
Definition
| By forming a wall between the attachment points. That each daughter cell will get one copy of the genomic information |
|
|
Term
| What are the attachment points in prokaryotic cells? |
|
Definition
| The points where the DNA are attached to the plasma membrane |
|
|
Term
| How does the size of prokaryotic genome compare to the human genome? |
|
Definition
| Prokaryotic: 9 million base pairs, human: 3 billion base pairs |
|
|
Term
| What is semi-conservative replication? |
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Definition
| What occurs in binary fission where one of the old strands forms half of DNA of each new cell (since there are two strands in each cell) |
|
|
Term
| How does DNA in eukaryotic cells pack? |
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Definition
| With histones. DNA wraps around a histone octamer core |
|
|
Term
|
Definition
| Proteins that have been highly conserved throughout evolution that have a lot of basic R groups. Nucleic Acids are acidic so they attract the basic histones |
|
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Term
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Definition
| A histone octamer with DNA wrapped around it |
|
|
Term
| What is the primary level of DNA packing? |
|
Definition
| “beads on a string” model where there is a nucleosome bead on DNA thread |
|
|
Term
| What is the secondary level of DNA packing? |
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Definition
| Packed nucleosomes on the “30nm fiber” Histones help the DNA pack into this 30nm fiber (this is eventually wound into loops that go into thecondensed chromatin, visible in metaphase.) |
|
|
Term
| What is the difference between mitosis and interphase? |
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Definition
| Interphase is the phase when cells are not dividing. |
|
|
Term
| How does the cell divide? What does this ensure? |
|
Definition
| By forming a wall between the attachment points. That each daughter cell will get one copy of the genomic information |
|
|
Term
| What are the attachment points in prokaryotic cells? |
|
Definition
| The points where the DNA are attached to the plasma membrane |
|
|
Term
| How does the size of prokaryotic genome compare to the human genome? |
|
Definition
| Prokaryotic: 9 million base pairs, human: 3 billion base pairs |
|
|
Term
| What is semi-conservative replication? |
|
Definition
| What occurs in binary fission where one of the old strands forms half of DNA of each new cell (since there are two strands in each cell) |
|
|
Term
| What are the factors that make cell division more complicated in eukaryotic cells than prokaryotic? |
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Definition
| Eukaryotes are more complex because they have multiple chromosomes, they are diploid organisims so chromosomes exist as homologous pairs, chromosomes are in the nucleus, replication occurs through mitosis not binary fission, and all cells(humans?) have 2 copies of each chromosome EXCEPT the sex chromosome |
|
|
Term
| How does DNA in eukaryotic cells pack? |
|
Definition
| With histones. DNA wraps around a histone octamer core |
|
|
Term
|
Definition
| A histone octamer with DNA wrapped around it |
|
|
Term
| What is the primary level of DNA packing? |
|
Definition
| “beads on a string” model where there is a nucleosome bead on DNA thread |
|
|
Term
| What is the secondary level of DNA packing? |
|
Definition
| Packed nucleosomes on the “30nm fiber” Histones help the DNA pack into this 30nm fiber (this is eventually wound into loops that go into thecondensed chromatin, visible in metaphase.) |
|
|
Term
| What is the difference between mitosis and interphase? |
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Definition
| Interphase is the phase when cells are not dividing. |
|
|
Term
| When do cells not divide? |
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Definition
| In interphase, or also some mature cells stop dividing (ex. brain and liver cells) brain cells will never go back to replication whereas liver cells can if they are damaged. |
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Term
| What occurs during the s phase? |
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Definition
| The replisomes replicate DNA, however there are many points of replication in eukaryotic cells because there is so much DNA that the replisomes have to start in lots of places. This process makes the chromosomes diploid (right term?) for mitosis |
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|
Term
| How many chromatids are there on each chromosome in the G1 phase? |
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Definition
|
|
Term
| How many chromatids are there on each chromosome in the G2 phase? |
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Definition
| Two (one of two identical copies of DNA) |
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|
Term
| What is the visual difference between chromosomes in the G2 phase and mitotic chromosomes? |
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Definition
| Mitotic chromosomes are more dense (which is why we can see them) |
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|
Term
|
Definition
| The attachment site for microtubules at the centromere region |
|
|
Term
|
Definition
| A complete set of chromosomes in a series (i.e. all of the human chromosomes lined up) |
|
|
Term
|
Definition
| One copy of each chromosome |
|
|
Term
|
Definition
| Two copies of each chromosome |
|
|
Term
| What does “acrocentric” centromere? |
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Definition
| Means that the centromere is not always at the middle of the chromosome |
|
|
Term
| What does “telocentric” mean? |
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Definition
| Means that the centromere is at the end, as on chromosome #13 |
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|
Term
| How do we know that the centromere is “acrocentric”? |
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Definition
| because you can stain the telomeres and kinetichore |
|
|
Term
| What is the difference between an interphase nucleus (active) vs. an inactive nucleus? |
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Definition
| In an active cells the heterochromatin converts to euchromatin so the heterochromatin (dark) moves to the edges of the cell |
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|
Term
|
Definition
| The chromosomal part of cell division. |
|
|
Term
| What is the goal of mitosis? |
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Definition
| To ensure that a complete set of chromosomes goes into each daughter cell |
|
|
Term
| What are the four phases of mitosis? |
|
Definition
| Prophase, metaphase, anaphase, and telophase |
|
|
Term
| What stops happening in prophase? |
|
Definition
| Gene activity stops, the nucleous disappears, the cell stops making ribosomes |
|
|
Term
| What starts happening in prophase? |
|
Definition
| There are now 2 centrioles that move away from each other to opposite poles in the cell |
|
|
Term
| What happens to the chromosomes in prophase? |
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Definition
| They are already in replicated (diploid) form, become visible |
|
|
Term
| DO plants have centrioles? |
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Definition
|
|
Term
| What happens in prophase after all of the other processes have occurred? |
|
Definition
| The nuclear envelope breaks down |
|
|
Term
| What develops in prophase between the two centrioles? |
|
Definition
|
|
Term
| When does metaphase start? |
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Definition
| When the mitotic spindle is fully formed, the centrioles are at opposite poles and the MTs are attached to the centrioles at the kinetichore |
|
|
Term
| What happens in metaphase? |
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Definition
| The chromosomes are dragged by the MTs until they are centered in the middle of the cell on the “metphase plate” |
|
|
Term
| What happens in anaphase? |
|
Definition
| The two sister chromatids have separated and each is pulled towards one pole as the poles move away from each other |
|
|
Term
| What are the three kinds of spindle microtubules? |
|
Definition
| Polar microtubules, aster fibers (aka unattached microtubules) and kinetichore microtubules. |
|
|
Term
| What do polar microtubules do? |
|
Definition
| They overlap and go from one pole/centriole to the other |
|
|
Term
|
Definition
| They attach to the inside of the plasma membrane and may account for pole movement by pulling towards the plasma membrane |
|
|
Term
| What do kinetichore fibers do? |
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Definition
| They go from the pole to the kinetichore and cause the chromosomes to move towards the poles. |
|
|
Term
| What happens in anaphase A? |
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Definition
| the chromosomes are pulled apart, split and move towards the poles. The MTs shorten to pull the chromosomes in |
|
|
Term
| What happens in anaphase B? |
|
Definition
| the poles move away from each other, the polar microtubules push the poles apart and the poles are pulled away from each other at the poles. |
|
|
Term
| How do polar microtubulules allow for the poles to move away from each other? |
|
Definition
| They grow in the middle at the (+) end |
|
|
Term
| How do the kinetochores of the chromosomes move towards the poles? |
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Definition
| The kinetichore on the chromosome eats away at the MT and depolymerizes it so that the tubulin dimers fall out. There is also some depolymerization at the pole end but not as much |
|
|
Term
| When does telophase begin? |
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Definition
| Once the chromosome reaches the poles |
|
|
Term
| What occurs during telophase? |
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Definition
| The chromosomes de-condense, gene activity resumes and the nucleolus reappears and then the cell divides in two |
|
|
Term
| What is cell splitting called? |
|
Definition
|
|
Term
| What triggers progression through mitosis? |
|
Definition
| Phosphorylation. This is what controlled the assembly and disassembly of the nuclear lamina. |
|
|
Term
| How does cytokinesis occur in animal cells? |
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Definition
| There is a contractile ring of actin filaments that are along the dividing groove. The ring tightens to the point that the cell is cleaved and it divides. **there are controls to make sure that the chromosomes will go into both cells |
|
|
Term
| How does cytokinesis occur in plant cells? |
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Definition
| Instead of actin binding, the cell begins to assemble cell components and make a cell plate which will eventually become a cell wall. *there is a way to make the result bigger otherwise cells would get smaller and smaller |
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|
Term
| What is the main difference between mitosis and meiosis? |
|
Definition
| There are 2 rounds of meiosis |
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|
Term
| What are the 2 main goals of meiosis? |
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Definition
| To generate genetic diversity (scramble up genetic information, produce sex cells) and to reduce the chromosome # by half—i.e.t o make a diploid cell haploid |
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|
Term
| Why does the cell need to reduce the chromosome # by half? |
|
Definition
| Since we are combining two sex cells we alternate between diploid and haploid cell phases. I don’t get this |
|
|
Term
|
Definition
| Germ line cells. This is what you do to produce sex cells, this is what passes genetic information on. |
|
|
Term
| When do germ cells develop? |
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Definition
| Very early in development since you do not want to damage them |
|
|
Term
| When meiosis starts, how many chromosomes are there? |
|
Definition
| 2n; chromosomes have already replicated, become visible |
|
|
Term
| What occurs in middle meiotic prophase? |
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Definition
| The homologous chromosomes shorten and thicken; chromosome synapse and crossing over occurs |
|
|
Term
| What occurs in late meiotic prophase? |
|
Definition
| The results of crossing over are visible as chiasmatas, the nuclear envelope begins to disappear and the spindle begins to form |
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|
Term
| If there are 3 homologous pairs how many possible gametes are there? |
|
Definition
|
|
Term
| What are the two ways of developing genetic diversity? |
|
Definition
| Random or independent assortment and crossing over (aka chromosomal recombination) |
|
|
Term
| What occurs in crossing over? |
|
Definition
| Chromatids break and are rejoined at the same location. I.e. swap analogous parts of the chromosome |
|
|
Term
|
Definition
| When chromosomes are fully paired, homologues are closely associated and crossing over can occur |
|
|
Term
| What exists in between the two homologues during synapsis? |
|
Definition
| Recombination nodules and the synapsis complex, a series of proteins that holds the homologues together (?) |
|
|
Term
|
Definition
| Two homologous diploid chromosomes during crossing over when they are linked together by chiasmata |
|
|
Term
|
Definition
| The crossover sites on chromosomes during crossing over |
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|
Term
| What occurs during meiotic metaphase I? |
|
Definition
| Assembly of spindle is completed. Each chromosomal pair (bivalent or tetrad) aligns across the equatorial plane of the spindle |
|
|
Term
| What occurs during meiotic anaphase I? |
|
Definition
| homologous chromosome pairs separate and migrate to opposite poles. “Reduction Division” occurs. Analog pairs separate and go into 2 different cells. One diploid chromosome in each cell. |
|
|
Term
| What occurs during meiotic telophase I? |
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Definition
| chromosomes (each with 2 sister chromatids) complete migraption to poles. New nuclear membranes can form |
|
|
Term
| What happens in cytokinesis? |
|
Definition
| Cell divides into 2 cells. **chromosomes don’t replicate** Each cell is still diploid |
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|
Term
| What happens in the second phase of meiosis? |
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Definition
| The same series now occurs within each cell. But since each cell has one copy of diploid chromosomes instead of two copies of diploid cells the result is 4 haploid cells each with one haploid chromosome. |
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|
Term
| When does the second round of division occur in meiosis that leads to 4 haploid cells? |
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Definition
| During anaphase 2 a.k.a.”mitotic-like division” |
|
|
Term
| Can haploid cells do meiosis? |
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Definition
| No, only diploid cells because they have to have 2 copies of the same chromosome |
|
|
Term
| How many final haploid cells are generated from one diploid cell in meiosis? |
|
Definition
|
|
Term
| How many chromosomes are in the final cells generated from meiosis compared to the starting cells? |
|
Definition
| n, i.e. half as many since you started with 2n |
|
|
Term
| What are the major differences in the metaphase to anaphase transition in meiosis compared to mitosis? |
|
Definition
| In meiosis the chromosomes are originally connected at the chiasmata and there are 2 homologues. In mitosis the sister chromosomes remain separate. MTs attach only on one side in meiosis and on two sides in mitosis. Sister chromosomes stay together in meiosis, but homologues (bivalents) are pulled apart as chiasmata slide to ends. In mitosis the sister chromsomes are pulled apart. |
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|
Term
| What is the main difference between male and female gameogensis in humans? |
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Definition
| Men’s cells keep replicating (start with 2n and end up with 4 n gametes) whereas female cells start with 2n and end with one n cell. Female cells literally have all of their eggs in one basket |
|
|
Term
| How many eggs get out in each cycle for female sex cells? |
|
Definition
|
|
Term
| When does the first meiotic division start occurring in female cells? |
|
Definition
|
|
Term
| What is the signal for the second phase of meiosis? |
|
Definition
|
|
Term
| What is differentiation in male sex cells? |
|
Definition
| cells differentiate into a further cycle (change kind of cell?) |
|
|
Term
| What is the different between human and fungus production of germ line cells? |
|
Definition
| Humans are always diploid except a brief haploid moment. Fungus are always haploid except a brief diploid moment. |
|
|
Term
| What is meiosis called in Fungi? |
|
Definition
| Zygotic meiosis (only zygote is diploid) |
|
|
Term
| What does gametic meiosis mean? |
|
Definition
| That only the gamete is haploid (everything else is diploid) |
|
|
Term
| What occurs in sporic meiosis/how is it different from human meiosis? |
|
Definition
| Alternate between multicellular haploid cell and multicellular diploid cell |
|
|
Term
| What does it mean to be homozygous? |
|
Definition
| To have two of the dominant or recessive alleles: i.e. PP or pp |
|
|
Term
| How did Mendel get accurate results when he crossed different plants? |
|
Definition
| He had large numbers which enabled him to detect a pattern of the 3:1 ratio |
|
|
Term
| What is Mendel’s First Law/Law of Segregation? |
|
Definition
| when any individual produces gametes, the copies of a gene separate so that each gamete receives only one copy, The recessive trait can re-express in the F2 generation |
|
|
Term
|
Definition
| A form of a gene that codes for a particular phenotype. Ex. P = purple, p = white |
|
|
Term
| What does it mean to be heterozygous? |
|
Definition
| To have one dominant and one recessive allele, ex. Pp |
|
|
Term
| What is a monohybrid cross, what is the phenotypic ratio associated with it? |
|
Definition
| When 2 heterozygous individuals are crossed; 3:1 dominant: recessive |
|
|
Term
| What is an example of an autosomal recessive trait? |
|
Definition
| Albinism, b/c you need aa to express it |
|
|
Term
| What is an example of an autosomal dominant trait? |
|
Definition
| Huntington’s disease, b/c you can get it with just H, 50% chance that kids will get it |
|
|
Term
| What is a monohybrid test cross? |
|
Definition
| When you test cross something with homozygous recessive. |
|
|
Term
| How do you know if the original seed was heterozygous from a monohybrid test cross? |
|
Definition
|
|
Term
| What is the phenotypic ratio with a dihybrid cross (so two genes)? |
|
Definition
| 9:3:3:1 There are 2 gene pairs so 2^2 is the number of phenotypes, the genotypes are 3^n, n is two so there are 9 genotypes |
|
|
Term
| What is Mendel’s Second Law/Law of Independent Assortment? |
|
Definition
| alleles of different genes assort independently of one another during gamete formation |
|
|
Term
| What is the phenotypic ratio with a dihybrid test cross? |
|
Definition
| 1:1:1:1 all 4 phenotypes are in equal ratios. Ex. test cross LlGg with llgg (same as lg) |
|
|
Term
|
Definition
| The percentage of the offspring that show the phenotype |
|
|
Term
| Why did Mendel choose peas? |
|
Definition
| Because it was easy to control which plants mated. |
|
|
Term
| What the male sexual organ in peas? |
|
Definition
|
|
Term
| What is the female sexual organ in peas? |
|
Definition
|
|
Term
| What important thing did Mendel always keep constant in his experiments? |
|
Definition
| He always started with true breeding plants |
|
|
Term
| What does the product rule state? |
|
Definition
| The probability of two independent events occurring together is equal to the product of probabilities of either event occurring alone |
|
|
Term
| What does the sum rule state? |
|
Definition
| The probability of two mutually exclusive events occurring together (ex. rolling a 6 or a 2 on a di) is the sum of their individual probabilities |
|
|
Term
| What is the caveat to the sum rule? |
|
Definition
| The probability of all mutually exclusive events must equal one |
|
|
Term
| How can we calculate the outcome of events with only two outcomes, like births? |
|
Definition
| With the binomial expansion: (p+q)^n where n is the # of outcomes (i.e. births) |
|
|
Term
| What can we use to help us figure out the coefficients for the terms in the binomial expansion? |
|
Definition
|
|
Term
| How many terms are there in a binomial expansion? |
|
Definition
| One more than the number of outcomes (i.e. the exponent plus one) |
|
|
Term
| What is the ratio (phenotypic or genotypic) of incomplete or partial dominance? |
|
Definition
|
|
Term
| Why does incomplete dominance occur? |
|
Definition
| Because heterozygous and homozygous dominant are not the same phenotype. |
|
|
Term
| what is the name of the process of how prokaryotes divide? |
|
Definition
|
|
Term
| what part of the bacteria attracts proteins for replication? |
|
Definition
|
|
Term
| what do the proteins do once they are on the bacteria? |
|
Definition
| the jump on the origin, open it up, and have unpaired dNA. other enzymes jump on the DNA nad start copying a new DNA strand |
|
|
Term
| where is new DNA made on prokaryotic cells? |
|
Definition
|
|
Term
| what are the enzymes called that replicate DNA in prokaryotic cells? |
|
Definition
|
|
Term
| where do replisomes start and end? |
|
Definition
| start at the origin, end on the opposite side of the circle at the terminus |
|
|
Term
| what are replication forks? |
|
Definition
| where DNA is copied in both directions starting at the 3' end. |
|
|
Term
| is prokaryotic DNA parallel or anti-parallel? |
|
Definition
|
|
Term
| what are the replication points called in prokaryotic DNA? |
|
Definition
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