Term
| When DNA mutations occur, they can effect genes that code for what? |
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Definition
| proteins, tRNA, mRNA, nontranslated sequences like enhancers. |
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Term
| Why isn't cancer inhereted? |
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Definition
| It's a mutation that is not in the germ line. Somatic cells do not pass on their genetic info. |
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Term
| In what rare cases are somatic cell mutations inhereted? |
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Definition
| When it is in vegetative propagation or asexual reproduction. |
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Term
| What are the two types of phenotypic variation? |
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Definition
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Term
| What two things make up genotypic and phenotypic variation? (this one doesn't really have any logic attached to it_ |
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Definition
1. generation of new genotypes and thus phenotypes
2. phenotypic variations in a population |
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Term
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Definition
| alteration of a gene or chromosome (verb) or the altered state of a gene or a chrom (noun) |
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Term
| What types of point-mutations are there? |
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Definition
| base pair substitutions and frame shift mutations |
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Term
| what are the two types of base pair substitutions? |
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Definition
1. transtions: purine for purine/pryi for pyri (a for g or c for t)
2. transversions: pur for pyri and vise versa (a or G for C or t) |
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Term
| how many tupes of transversions are there? |
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Definition
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Term
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Definition
| correspondance betwis aa and RNA codons and DNA triplets |
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Term
| whats the wobble hypothesis? |
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Definition
| there is some wobble room in the genetic code. more than one sequence can code the same aa. |
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Term
| what are synonymous mutations and nonsynonymous mutations? |
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Definition
| synonymous is when a RNA base change doesn't actually affect the aa that the codon sequences for. this is because of the redundancies in the genetic code. nonsynonymous is the opposite. |
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Term
| what are frame shift mutations? |
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Definition
| a base is deleted causing the reading frame to change. |
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Term
| what are the two types of frameshift mutations? |
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Definition
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Term
| why are human gene mutations so rare? |
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Definition
| we have proofreading capabilities. |
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Term
| why are human gene mutations so rare? |
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Definition
| we have proofreading capabilities. |
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Term
| how are mutation rates measured? |
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Definition
| # of independent origins pre gene per unit time. |
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Term
| what are 3 big examples of discrete polymorphisms? |
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Definition
1. sexual dimorphism
2. color patterns
3. flower colors |
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Term
| in humans which sex is the heterogametic sex? |
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Definition
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Term
| what do plethodon jordani exhibit? how do they do it? |
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Definition
| they show discrete polymorphism by having 4 distanct color patterns/phenotypes in one spp |
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Term
| what are two other sp that show this same type of thing? |
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Definition
1. flower color in linanthus parryae
2. color phases of snow geese. |
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Term
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Definition
| polygenic trait, when multiple individual loci follow mendelian genetics to effect on characteristic |
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Term
| what is a polygeneic trait? |
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Definition
| single phenotypic trait controlled by more than one loci |
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Term
| how are polygenic traits measured |
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Definition
| quantitatively, numerically |
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Term
| what is a good example of a polygenic trait? |
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Definition
| cranial horn length in lizards |
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Term
| why don't female lizards show cranial horns when they have the gene? |
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Definition
| they have genetic supressors |
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Term
| what does 0 represent on a bell curve? |
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Definition
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Term
| what are the x and y axis on a bell curve? |
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Definition
x: standard deviation
y: frequency |
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Term
| what shape of bell curve would exhibit greater variance? how is this represented in a st. Dev? |
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Definition
| a wider bell=greater varianc=larger st. d |
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Term
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Definition
| geographical areas in which an intermediate phenotype is exhibited between two seemingly discrete areas that show seemingly discrete traits |
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Term
| what are two example of intergrade zones? |
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Definition
| flicker woodpeckers and black rat snakes |
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Term
| when do you use sigma and when do you use s in detwemining variance? |
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Definition
| sigma is for when you measure every single individual in a pop. s is for when you take a sample |
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Term
| what is phenotypic variance? |
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Definition
| measure of how values of a trait vary abouta cetntral mean |
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Term
| what is variance symbolized as? |
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Definition
| sigma squared or s squared |
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Term
| what is the equation for variance of a total populta |
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Definition
|
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Term
| What is phenotypic variance and what contributes to it? |
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Definition
Phenotypic variance is: how the values of a trait vary about a central value (mean)
It consists of:
Additive Variance, Gene by Environment interactions, Experimental Variance and Epistatic Interactions. |
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Term
| What are the two descriptions of variance and how are they different? |
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Definition
sigma-squared and s-squared.
Sigma-squared is used when you measure every individual in a population and s-squared is used when you are just measuring a sample of the population. |
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Term
| what is used to represent the mean? |
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Definition
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Term
| What is used to represent the total population? total sample size? |
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Definition
|
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Term
| what is the sum of squares? |
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Definition
| take each value, subtract it from the mean, and square it. Then add all these up |
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Term
| what is the equation for variance when you have only a sample of the population? |
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Definition
|
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Term
| what's the equation for variance when you can measure the whole population? |
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Definition
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Term
| Why is variability important? |
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Definition
| It is the basis for natural selection: duh. |
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Term
Describe environmental variance:
give an example |
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Definition
portion of Vp (phenotypic variance) that results from RANDOM, environmentall induced variation among individuals. Could also be from experimental error.
example: beak length may be influenced by chance differences among individuals in energy acquisition (food supply, in utero enviro etc) |
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Term
| what is another name(s) for environmental variance? |
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Definition
| Also called proximate variation or error variation. |
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Term
| What is heritabality in terms of equations and such? |
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Definition
H2
it is the proportion of variance in a phenotypic character w/in a population that is due to individual genetic differences that can be inherited by offspring.
Va/Vp
Where Vp is the total phenotypic variance and Va is the additive (genetic) variance.
When H2=1 all the variation is due to genetic stuff |
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Term
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Definition
Additive variance is essentially genetic variance.
It represents variability of a trait due to the effects of several genes/loci |
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Term
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Definition
| Epistatic interactions: interactions between 2+ lovi in which the expression of one or more loci is modified. |
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Term
| describe an example of Vi |
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Definition
hair color in mice
there are two loci. each with two alleles.
Locus 1=A/a agouti/black
Locus 2=C/c color/albino |
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Term
| describe the heritability of Vi |
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Definition
epistatic interactions are not inheritable unless they are linked (on the same chromosome)
this makes sense if you think about it for a minute.
if they are linked than they will not only be inherited but they may be naturally selected. |
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Term
| What are gene x environment interactions? |
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Definition
these are variable environmental cues that:
1. affect the expression of genes
2. affect nueral and hormonal muchanisms |
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Term
| what is the norm of rxn of a genotype? |
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Definition
| set of phenotypes that can be expressed by a single genotype in different environments. |
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Term
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Definition
describes a genotype that can produce multiple phenotypes in multiple enviros
ex. there are nemoria caterpillars that look different based on what time of year they emerge. If they come out during spring when oak flowers are present they have catkins on their skin that makes them look like the oak branches with buds on them. If they come out druing summer when only leaves are present they are furry like the twig branches. |
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Term
| give a botanical example of plasticity |
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Definition
runnunculus: aquatic buttercups
depending on their depth they have different leaf shapes.
some times have small, spindly things to maximize CO2 absorption and some have big leaves to mazimize light absorption b/c they don't have a problem absorbing CO2. |
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Term
| What is the equation for phenotypic variance |
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Definition
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Term
| What are point mutations? |
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Definition
changes in dna base sequence pairs that cause changes in aa sequence
1. base pair substitution
2. frame shift substitutions |
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Term
| types of of phenotypic variation in populations: |
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Definition
discrete polymorphism
continuous variation |
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Term
background value
what's it used for
ex |
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Definition
minimum value attained by genotype
used to determine Va. you start with the background value and then add the other variances at different loci.
ex. in beak length the minimal beak length is .25cm, then additional loci add on to that. |
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Term
| Experimentally how can we determine Vp? |
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Definition
It is the standard deviation.
Or it is the square root of s2
Vp=√(∑(Yi-Ȳ)2)/(n-1))
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