Which of the following is not a source of variation of alleles?,the frequencies of four alleles of a trait?

Choices for first one are:


a.crossing over during meiosis


b. the number of alleles during meiosis


c. recombination during meiosis


d. independent assortment in meiosis


2nd one:


a. 100%


b. 25%


c. 50%


d. 75%


Other questions:


Two factors that contribute to evolution


a. genetic recombination and population


b. species and population


c. inbreeding and population


d. mutation and genetic recombination


Gene frequencies are not affected by


a. frequent mutation


b. natural selection


c. random mating


d. genetic drift


Small population have many problems maintaining stable numbers, partly becasue of


a. artificial selection


b. the founder effect


c. inbreeding depression


d. limited resources


A change in allele frequencies is more likely to produce


a. microevolution


b. inbreeding


c. mutation


d. macroevolution


Gene flow promotes evolution through


a. selective breeding


b. inbreeding


c. mutation in species


d. migration between gene pools

Which of the following is not a source of variation of alleles?,the frequencies of four alleles of a trait?
I sure hope this isn't your homework that I'm answering, haha.


1. (b) Number of alleles is predetermined. Crossing over is not correct because "chromatids break and may be reattached to a different homologous chromosome." (Thinkquest.) Recombination is basically the same thing, and in independent assortment the chromosomes that end up in a newly-formed gamete are randomly sorted from all possible combinations of maternal and paternal chromosomes, so that's not right.





2. (b) 100/4 = 25%





3. (d) Mutations help a population with survival by letting the ones with more environment-adaptive traits to prevail (Natural selection) and genetic recombination allows with genetic diversity and phenotypical diversity, which also ties into natural selection. Species and population do not contribute to evolution.





4. (c) Random mating is when two organisms make without regards to genotype.





5. (c) Inbreeding depression. Inbreeding makes more disadvantageous recessive traits show up in a population, causing numbers to fluctuate.





6. (a) Macroevolution is when you have something as drastic as a new species. Microevolution is evolution within a species.





7. (d) Definition of gene flow is basically "the transfer of alleles of genes from one population to another." (Wikipedia)