protiens produced by the B-cells of the immune system that recognize foreign substances (namely, viruses, bacteria, and so forth) and target them for destruction
antigen
foreign substances that are recognized by antibodies
gene conversion
the phenomenon in which one allele is converted to another allele due to genetic recombination and DNA repair
heteroduplex
a double-stranded region of DNA that contains one or more base mismatches
homologous recombination
recombination between DNA segments that are homologous to each other
hybrid dysgenesis
a syndrome involving defective Drosophila offspring, due to the phenomenon that P elements can transpose freely.
insertion sequence
the simplest transposable elements. They are commonly found in bacteria.
integrase
an enzyme that functions in the integration of viral DNA or retroelements into the host chromosome
inverted repeat
DNA sequences found in transposable elements that are identical (or very similar) but run in the opposite directions
locus
the physical location of a gene within a chromosome
long terminal repeat sequence
sequences containing many short segments that are tanemly repeated. They are found in retroviruses and viral-like retroelements
prophage
the first phase of M phase. The chromosomes have already replicated and begin to condense.
resolution
the last stage of homologous recombination, in which the entangle DNA, strands become resolved into two separate structures.
retroelement
a type of transposable element that moves via an RNA intermidiate
reverse transcriptase
an enzyme that uses an RNA template to make a complementary strand of DNA.
selfish DNA theory
the idea that transposable elements exsist because they possess characteristics that allow them to multiply within the host cell DNA and inhabit the host without offering any selective advantage
sister chromatid exchange
the phenomenon in which crossing over occurs between sister chromatids, therby exchanging identical genetic material
transposable element
a small genetic element that can move to multiple locations within the host's chromosomal DNA
transposase
the enzyme that catalyzes the transposition of trasposable elements
transposition
the phenomenon of transposon movement
transposon tagging
a technique for cloning genes in which a transposon inserts into a gene and inactivates it. The transposon-tagged gene is then cloned using a complementary transposon as a probe to identify the gene
Which statement regarding recombination is false?
B) Sister chromatid exchange is a form of recombination.
Crossing over occurs in both mitosis and meisosis.
a) True
b) False
a) True
Harlequin chromosomes:
D) All of the above.
Which of these describes a Holliday junction?
helix.
C) An interaction of two strands of DNA from homologous chromosomes.
After isomerization and resolution, the resulting chromosomes are:
E) Recombinant chromosomes with a heteroduplex region.
Considering the steps listed below, identify the correct sequence of events
proposed by the double-strand break model of recombination.
I. Strand
invasion and D loop formation.
II. DNA gap repair synthesis.
III.
Generation of single stranded DNA segments.
IV. Resolution.
A) III, I, II, IV
The existence of single Holliday junctions is strong support for the Holliday
model of recombination.
a) True
b) False
b) False
What is gene conversion?
a) A process by which a gene is rendered nonfunctional.
b) A process that changes an allele to the allele existing on the homologous
chromosome.
c) A process that restores the wild type function of a gene.
d) A process that creates a new allele of a gene.
e) None of these.
b) A process that changes an allele to the allele existing on the homologous
chromosome.
Author
hbic_1
ID
121140
Card Set
Gentics Ch.17: Recombination and Transposition at the Molecular Level
Description
Genetics Ch.17: Recombination and Transposition at the Molecular Level
