Some MCQs

[biology_06er]

Hi there,

Just want to know if these MCQs are right (again) as I had a super hard exam yest..

the mating of close relatives can be detrimental for which reason?
it increases the probability that individuals homozygous for a recessive genetic disease allele will be produced
it increases the rate at which new genetic variants spread in a population
it decreases the average fitness genetic disease allele
it increases the rate of mutation, therby creating new types of genetic disease
it increases the probability that a dominant allele will mutate to a recessive genetic disease allele

which statement is TRUE:
BAC vectors in e.coli are based on the pMBI replicon and replicon and replicate at copy numbers of 200 copies per cell
plant gene transfer is more advanced than animal gene transfer because more is known about plant genes than animal genes
agrobacterium tumefaciens is the most widely used vector system in plants because the Ti plasmid that replicates at high copy number in plant nuclei
viral replication origins are used in mammalian shuttle vectors becasue there are no natural plasmids in mammalian cells
yeast vectors based on the 2-micron plasmid replicate at copy numbers of 1-2 per cell

which of the following does NOT occur in stochastic lineage sortng?
ancient polymorphisms are retained for long eriods of time in a new species
ancient polymorphismsare lost from species as a result of random drift
ancient polymorphisms are modified within species by the ongoing substitution process
populations, each carrying a sample of the species' polymorphisms, become isolated from one another
selection for adaptation to local conditions results in species retaining different polymorphisms

cheers,

[AstusAleator]

I agree with your first and last answers. The middle... I dunno... I'm not up to date on my micro-genetics.

[biology_06er]

Hey there,

Thanks, can you see if these ones are right?

why are genetic markers useful in identifying quantitative trait loci?
genetic markers can be closely linked to genes which affect phentotype
genetic markers have a high rate of mutation
genetic markers are responsible for differences in phenotype
every genetic marker is associated with a gene of large efect
genes of large effect occur in genome regions which are free of markers

which is true with regard to population studies?
association studies can only be used to find genes which cause a disease
a new set of genetic markers is required for each population association study
mixing samples from different populations with different marker frequencies can produce statistically false associations
association studies can only find genes of large effect, but not casual SNPs
a large number of SNP markers (>300000) are required for fine-scale gene analysis

the neutral theory of gene evolution implies that:
the date of evolutionary divergence of two species can be estimated from their genetic differences
natural selection does not exist
only those genetic changes whichhave no selective effect will survive in a population
all genetic differences between populations are the reult of random processes
the overall rate of evolution is the same for every gene

which of the following describes a situation where we cannot use open reading frames to locate genes in a genome?
when there are multiple initiation condons (ATG) in the seaquence
when we don't know the function on a gene
when the relative frequency of synonymous codons is non-random
when annotating a eukaryote genome
when genes are encoded in different reading frame

which of the following is FALSE?
quantitative traits are not inherited in a mendelian fashion
a large proportion of the variation in complex traits can be caused by environmental variation
selection is not effective when the narrow heretability is low
raising individuals under controlled conditions will help us to estimate the relative contributions of genetic and environmental factors to the variation in a trait observed in a population
the environment in which an organsim develops will influence its phenotype

Thanks!...I know theres heaps...but knowing if im wrong or right will allow me not to think about it as much

[mith]

I think the last one in the second post is already validated by twin studies, so I think it's true.