Term
| what is the ratio for incomplete or partial dominance? |
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Definition
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|
Term
| What antibody does A blood have? |
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Definition
|
|
Term
| what antibody does AB blood have? |
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Definition
|
|
Term
| what antibody does O blood have? |
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Definition
|
|
Term
| what is the expected ratio in a dihybrid cross? |
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Definition
|
|
Term
| what is the distribution of phenotypes for multiple genes? |
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Definition
| a normal distribution/gausian curve |
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Term
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Definition
| a measure of how much a trait is due to the environment, the fraction of variability due to genetic effects. |
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Term
| how can you determine if a gene is sex influenced? |
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Definition
| trait will not distribute evenly among sexes, but it is NOT on the sex chromosome |
|
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Term
| what does it mean for a gene to be sex influenced? |
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Definition
| it means that a gene can effect members of each sex differently. ex. baldness is dominant in men and recessive in women. |
|
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Term
| what is a sex limited gene? |
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Definition
| one that ONLY expresses in one sex or another but is not on the sex chromosome |
|
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Term
| what does epistatis mean? how can we detect it from a phenotypic ratio? |
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Definition
it means standing upon, so when the expression of one gene affects the expression of another gene.
We can detect it from a skewed 9:3:3:1 ratio |
|
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Term
| what are some environmental factors that effect genes we've learned about? |
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Definition
| temperature--effects color of siamese cats; drugs: thalidomide, effected limb formation even though drug was intended to combat morning sickness, |
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Term
| in a pedigree what sex is indicated by a circle, what by a square? |
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Definition
| women are circles, men are squares |
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Term
| What risk is increased with a consanguinous marriage? |
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Definition
| the risk that recessive genes will be brought back together |
|
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Term
| what does autosomal mean? |
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Definition
| that the gene is not sex-linked |
|
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Term
| what are the visual clues in a pedigree if a trait is autosomal recessive? |
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Definition
-most affected children have normal parents
-two affected parents will always have affected children |
|
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Term
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Definition
| the nucleic acid sequence |
|
|
Term
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Definition
|
|
Term
| what is a reciprocal cross? |
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Definition
| when a sex linked gene is crossed between a male with the trait and a female without the trait. In the f2 generation all possible combinations will be expressed |
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Term
| how can we tell from a pedigree if a gene is recessive x linked? |
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Definition
often skips a generation (criss-cross inheritance), and the affected son can have parents with a normal phenotype (means mom is a carrier)
-ratio of inheritance is skewed male
-ex. Duchenne muscular dystrophy |
|
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Term
| how can we tell from a pedigree if a gene is autosomal dominant? |
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Definition
-only need one copy of gene to express it (ex. Huntington's)
-affected children usually have an effected parent (unless it's a mutation)
-doesn't skip generations
-kids have a 50% chance of getting the disease |
|
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Term
| what does atavistic mean? |
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Definition
| ancestral, probably all early humans expressed this gene |
|
|
Term
| what is an example of a Y-linked trait? |
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Definition
|
|
Term
|
Definition
| genes that are located on the same chromosome |
|
|
Term
| do linked genes sort independently? |
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Definition
|
|
Term
| does crossing over effect results of linked genes? |
|
Definition
|
|
Term
| what is the ratio of phenotypes in a dihybrid test cross? |
|
Definition
|
|
Term
| changes are always ___ in crossing over? |
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Definition
|
|
Term
| what is another term for crossing over? |
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Definition
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|
Term
| when genes are not linked, what is the ratio of phenotypes? what is percentage of non-parental types? |
|
Definition
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|
Term
| when genes are linked and close together, what is the ratio of phenotypes? what is percentage of non-parental types? |
|
Definition
|
|
Term
| when genes are linked and far apart, what is the ratio of phenotypes? what is percentage of non-parental types? |
|
Definition
9:9:1:1
low percentage ~5 or 10% |
|
|
Term
| the farther apart genes are the _____ a chiasmata is going to be between them |
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Definition
|
|
Term
| how can you identify the cross over gene in a three point test cross? |
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Definition
| it has the smallest number in terms of phenotype. it is the middle gene |
|
|
Term
|
Definition
| the distribution and separation of chromosomes in meiosis I or of sister chromosomes in meiosis II |
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|
Term
|
Definition
| when chromosomes do not sort properly/fail to sort and two end up in one cell |
|
|
Term
| what is primary non disjunction? |
|
Definition
| when chromosomes don't sort (i.e. X AND Y go into one cell) |
|
|
Term
| what is secondary non disjunction? |
|
Definition
| when sister chromatids don't sort in meiosis II |
|
|
Term
| are big or small genes more likely to experience non-disjunction? |
|
Definition
|
|
Term
|
Definition
| an abnormal number of chromosomes |
|
|
Term
|
Definition
| having 3 copies of one chromosome |
|
|
Term
| are missing genes or extra copies more likely to be lethal/make gamete non-viable? |
|
Definition
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|
Term
| downs sydrome occurs from what? |
|
Definition
| extra copy of chromosome 21 |
|
|
Term
| what are some of the charateristics of down syndrome? |
|
Definition
-high level of blood purines
-elevated risk of cancer
-simian line
-affable! |
|
|
Term
| if an individual had 3 copies of all chromosomes, would it survive? |
|
Definition
|
|
Term
|
Definition
| a full set of haploid chromosomes |
|
|
Term
|
Definition
| Turner syndrome: only one x copy, low fertility, extra skin at neck |
|
|
Term
|
Definition
| Triplo X, viable though most individuals are sterile |
|
|
Term
|
Definition
| Jacob's syndrome: 40% higher incidence in prison population, speculation that extra Y leads to more aggresive behavior |
|
|
Term
| what is XXY, XXYY or XXXY? |
|
Definition
| Kleinfelter's: long lower limbs, small breast development but genetically male, low fertility rate |
|
|
Term
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Definition
| when one of the x genes in females is turned off so that they both do not express. Decendents of that cell the same X is turned off. This is what normally happens |
|
|
Term
| in x inactivation what do we call the condensed x chromosome? |
|
Definition
| a barr body, looks like a little black spot |
|
|
Term
| what is a visual example of X inactivation? |
|
Definition
| calico cats: color depends on what colors are activated where. also skin cells in women |
|
|
Term
| when are sex organs developed? |
|
Definition
| approximately 10 weeks in. either Y gene turns testosterone production on or lack thereof leads to female genetalia |
|
|
Term
| what is an example of how the sex-determining gene is also a regulatory gene? |
|
Definition
| production of testosterone and estrogen effects other processes. ex. delay in making testosterone--> delay in sex organs "guevodoces" |
|
|
Term
| what is androgen insensitivity? |
|
Definition
| when testosterone receptors don't work so an individual is genetically male but phenotypically female |
|
|
Term
| what happens in CAH (Congenital Adrenal Hyperplasia)? |
|
Definition
| excess testosterone and reduced cortisol synthesis lead to masculization of extrnal organs in females |
|
|
Term
| what did the Stern experiment show? |
|
Definition
| confirmed that crossing over does involve breaking and rejoining a chromosome, and that crossing over leads to non-parental types |
|
|
Term
| what are polytene chromosomes? |
|
Definition
| chromosomes in the saliva of flies that are very enlarged, easy to see chromosomal abberations |
|
|
Term
| what are the 4 kinds of chromsomal mutations/aberrations |
|
Definition
1. deletion
2. translocation
3. insertion
4. duplication |
|
|
Term
| what happens in a chromosomal inversion |
|
Definition
| two genes are cut out, swapped, and put back in. i.e. abcd becomes acbd |
|
|
Term
| what happens in a chromosomal translocation? |
|
Definition
| section on one chromosome and another chromosome swap (i.e. bottom part of chromosome 2 swaps with bottom part of chromosome 5) |
|
|
Term
| what happens in a chromosomal deletion? |
|
Definition
| a part of a chromosome is completely lost |
|
|
Term
| what happens in a chromosomal duplication? |
|
Definition
| one section of the chromosome is duplicated and re-insterted |
|
|
Term
| what percent of failed fertilizations have a chromosomal defect? |
|
Definition
|
|
Term
| in a deletion, can a recessive trait express? |
|
Definition
| yes if the concordant gene on the other chromosome was deleted because now there is nothing to mask this gene |
|
|
Term
| what is a paracentric inversion? |
|
Definition
| an inversion that does NOT include the centromere |
|
|
Term
| what is a paricentric inversion? |
|
Definition
| an inversion that DOES include the centromere |
|
|
Term
| can a paracentric inversion affect gametes? |
|
Definition
| yes, leads to inviable chromosomes becuase they can me missing genetic information |
|
|
Term
| what are the two notable kinds of translocations? |
|
Definition
| Robertson translocation and philadelphia translocation |
|
|
Term
| what happens in a robertson translocation? |
|
Definition
| chromosomes break and rejoin to create a new long chromosome and a smaller fragment. now the full set has 3 copies of the critical area (think Down Syndrome) |
|
|
Term
| what happens in a philadelphia translocation? |
|
Definition
| two genes have translocations that puts two genes next to eachother than combined can have a new effect, ex. cancer-causing |
|
|
Term
| do prokaryotes/bacteria exchange genes during replication? |
|
Definition
|
|
Term
| what are the three ways that bacteria exchange genetic information? |
|
Definition
1. conjugation
2. transformation
3. transduction |
|
|
Term
| What occurs in bacterial conjugation? |
|
Definition
| an F+ bacteria (plasmid) hooks onto an F- bacteria w/out a plasmid via a pillus. This pillus (sometimes called the sex pillus) creates a bridge, and allows the F+ to replicate the plasmid, which codes for the ability to replicate genes, and inserts it in the F- cell, which becomes an F+ cell |
|
|
Term
| what is bacterial transformation? |
|
Definition
| taking in of naked DNA from the environment |
|
|
Term
| what is bacterial transduction? |
|
Definition
| a viral infection when a bacterial virus takes over a cell and makes it a viral production factory |
|
|
Term
| what is the PAR region on the Y chromosome? |
|
Definition
| are genes in the Y chromosome that are inherited like any other autosomal genes, not like sex-linked genes |
|
|
Term
| what is the function of the PAR region on the x and y chromosomes |
|
Definition
| The function of these pseudoautosomal regions is that they allow the X and Y chromosomes to pair and properly segregate during meiosis in males |
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