Mod 6 Ch. 19 Concept Check & Comprehension Questions Flashcards
Homologous recombination refers to the exchange between DNA segments that are..
Similar or identical in their DNA sequences
During the molecular process of homologous recombination between homologous chromosomes,
All of the above occur
A Holliday junction forms
Branch migration occurs
A heteroduplex region forms
A key difference between the original Holliday model and the double-strand break model is the way that..
The DNA strands are initially broken
Which of the following mechanisms can cause gene conversion?
DNA mismatch repair
DNA gap repair
With regard to phage lambda, the role of attachment sites is to..
Provide a site where the phage can align with the E. coli chromosome and become inserted there
During site-specific recombination that occurs for an antibody gene, the protein(s) that catalyze the joining of V and J domains to each other is/are:
Nonhomologous end-joining (NHEJ) proteins
Which of the following types of transposable elements involve an RNA intermediate?
Retro elements
The function of transposase is..
All of the above
To recognize inverted repeats
To remove a TE from its original site
To insert a TE into a new site
According to the selfish DNA hypothesis, TEs exist because..
They have characteristics that allow them to multiply within the chromosomal DNA of living cells
Two types of homologous recombination in eukaryotes.
What is the advantage of genetic recombination, which is depicted in part b?
An advantage of genetic recombination is that is may foster genetic diversity, which may produce organisms that have reproductive advantages over other organisms.
The Holliday model for homologous recombination.
Explain why a heteroduplex region may be produced after branch migration occurs.
A heteroduplex region may be produced after branch migration because the two strands are not perfectly complementary.
A simplified version of the double-strand break model.
Describe the structure and location of a D-loop.
During recombination, a D loop is formed when one DNA strand from one homolog invades the homologous region of the other homolog.
Gene conversion by gap repair synthesis in the double-strand break model.
Explain what happened to the b allele that allowed gene conversion to occur.
During gene conversion, the region of the gene that contained the genetic variation that created the b allele was digested away. The same region from the homolog, which carried the B allele, was then used as a template to make another copy of the B allele.
Different mechanisms of transposition.
Which of these mechanisms causes the TE to increase in number?
Retrotransposition always causes the TE to increase in number.
What is the function of reverse transcriptase?
Uses RNA as a template to make a strand of DNA
