Crossing Over and Recombinants

Which statement about linkage of genes is false?a. Crossing over results in recombinant phenotypes.b. Crossing over between two linked genes can alter phenotypes of progeny.c. Genes on the same chromosome assort independently.d. Genes on the same chromosome that are far apart have a higher recombination frequency than those that are close together.e. Genes on the same chromosome are said to be linked.

The process that determines the length of heteroduplex DNA on the chromatids is called branch migration.a) Trueb) False

Why is crossing over, or recombination, in meiosis a genetic advantage for an organism? Why is crossing over an advantage for a geneticist?

The frequency with which random events occur between two points is a function of the distance between those two points. How do we use this principle to map genes in eukaryotes?

All the genes on a single chromosome are physically linked. wo genes are genetically linked if they segregate together in meiosis more frequently than they segregate separately. Two physically linked genes that always segregate together show complete genetic linkage. Two genes on the same chromosome that usually but not always segregate together are incompletely or partially linked.How can two genes be physically linked but not be genetically linked? Explain the phenomenon of incomplete linkage.

Which process does not occur during recombination? a) Ligation b) Strand displacement c) Nicking of the sugar-phosphate backbone d) DNA polymerization

If the frequency of recombinant progeny (the recombination frequency) from a cross between one individual heterozygous at two loci and a second individual homozygous recessive at both of those loci is less than 50%, the two genes in question are genetically linked. What can we conclude about the genetic and physical linkage of two genes when the recombination frequency between those two genes is equal to 50%?

Why do mapping experiments become less accurate when the distances between genes become large? A) Crossover gametes become less common. B) Interference is greater when the distance between genes is large. C) Multiple-strand exchanges are more common. D) Recombination occurs less frequently in long chromosomes.

Which statement explains why the recombination frequency between two genes is always less than 50%? a) The genotype of the F1 gametes will always be 50% parental gametes and 50% recombinant gametes. b) Genes with a recombination frequency near 50% are unlinked and have an equal likelihood of being inherited together or separately. c) F1 gametes always have 50% of their alleles from each parental gamete. d) Recombination cannot be more than 50% because chromosomes are only 50% map units in length.