Need help with evolution questions:
1.) A haplotype is best defined as the ________________.
| haploid genotypes of all the gametes produced by a diploid individual |
| |
| ABO blood type conferred by an individual gamete |
| genotype of either the paternal or maternal chromosomal complement |
| multilocus genotype of a chromosome or gamete |
2.) Which of the following statements regarding linkage disequilibrium is true?
| Exists when D is less than zero, but not when it is greater than zero. |
| Is reduced by sexual reproduction. |
| Is increased by crossing-over during meiosis. |
| Is increased by any random sampling error that happens to create or destroy certain chromosome genotypes but not others. |
| Is reduced by selection that favors certain combinations of genotypes. 3.) Selection on multilocus genotypes in random-mating populations leads to linkage disequilibrium when _______________. | it reduces mutation rates | | it eliminates all haplotypes from the population | | it prevents crossing-over during meiosis | | some allele combinations confer greater fitness than do others 4.) When two loci are in linkage equilibrium, the allele carried on a chromosome at one locus is independent of the allele carried on the chromosome at another locus. When this is the case, _________________. | allele frequencies will not change over time | | the two loci (or, more specifically, their protein products) do not interact | | the frequency of each haplotype can be calculated by multiplying the frequency of its two alleles | | all possible haplotypes occur at equal frequency 5.) Which of the following accurately characterize(s) Muller's ratchet model for the selective advantage of sexual reproduction? | Drift establishes linkage disequilibrium because multilocus genotypes with few mutations are eliminated by chance events. | | In populations without sexual reproduction, deleterious mutations accumulate, eventually imposing such a burden that the population goes extinct. | | Sex is favored selectively because it recreates the zero-mutation genotypes lost due to drift. | | All of the above correctly characterize Muller's ratchet model for the evolution of sexual reproduction. | 6.) The genetic signature of recent positive selection on a locus is _______________. | high frequency and low linkage disequilibrium | | low frequency and low linkage disequilibrium | | low frequency and high linkage disequilibrium | | high frequency and high linkage disequilibrium 7.) Sexual reproduction is advantageous both in changing environments and in constant environments, compared to asexual reproduction. | False 8.) Sexual reproduction causes genetic recombination via crossing-over, which combines genotypes from different parents. | False 9.) One reason sex may be maintained in natural populations is proposed by the "Red Queen Hypothesis", which states that..... | genotypes created by sex are created by natural selection over and over | | recombination creating novel genotypes that can resist infection by parasites | | mutation load is reduced by novel adaptive mutations | | the ability of sex to fix multiple | | | | | | |