EXAM 2 STUDY GUIDE WITH TESTED
SOLUTIONS
◉ chromosome duplication. Answer: Mutation that doubles a
segment of a chromosome.
◉ tandem duplication. Answer: type of duplication where doubled
regions right next to original
◉ chromosome deletion. Answer: loss of a chromosome segment
◉ pseudodominance. Answer: The phenotypic expression of a single
recessive allele resulting from deletion of a dominant allele on the
homologous chromosome
◉ haploinsufficient gene. Answer: occurs when a diploid organism
has only a single functional copy of a gene and the single functional
copy does not produce enough of a gene product to bring about a
wild-type condition, leading to an abnormal or diseased state
◉ chromosome inversion. Answer: The detachment, 180° rotation,
and reinsertion of a chromosome arm
, ◉ position effect. Answer: Dependence of the expression of a gene
on the gene's location in the genome
◉ translocation. Answer: The process in which a segment of a
chromosome breaks off and attaches to another chromosome.
◉ Robertsonian translocation. Answer: Nonreciprocal chromosomal
transloccation that commonly involves chromosome pairs 13, 14, 15,
21, and 22. One of the most common types of translocation. Occurs
when the long arms of two acrocentric chromosomes (chromosomes
w/ the centromeres near the ends) fuse at the centromere and the 2
short arms are lost.
◉ fragile X syndrome. Answer: X-linked defect affeccting the
methylation and expression of the FMR1 gene. Associated w/
chromosomal breakage. The 2nd most common cause of genetic
mental retardation (after Down syndrome). Trinucleotide repeat
disorder (CGG)
◉ copy number variation. Answer: the phenomenon of duplication
or deletion of segments of DNA within a genome, so that different
individuals have different numbers of copies of a particular DNA
segment
◉ aneuploidy. Answer: Abnormal number of chromosomes.
SOLUTIONS
◉ chromosome duplication. Answer: Mutation that doubles a
segment of a chromosome.
◉ tandem duplication. Answer: type of duplication where doubled
regions right next to original
◉ chromosome deletion. Answer: loss of a chromosome segment
◉ pseudodominance. Answer: The phenotypic expression of a single
recessive allele resulting from deletion of a dominant allele on the
homologous chromosome
◉ haploinsufficient gene. Answer: occurs when a diploid organism
has only a single functional copy of a gene and the single functional
copy does not produce enough of a gene product to bring about a
wild-type condition, leading to an abnormal or diseased state
◉ chromosome inversion. Answer: The detachment, 180° rotation,
and reinsertion of a chromosome arm
, ◉ position effect. Answer: Dependence of the expression of a gene
on the gene's location in the genome
◉ translocation. Answer: The process in which a segment of a
chromosome breaks off and attaches to another chromosome.
◉ Robertsonian translocation. Answer: Nonreciprocal chromosomal
transloccation that commonly involves chromosome pairs 13, 14, 15,
21, and 22. One of the most common types of translocation. Occurs
when the long arms of two acrocentric chromosomes (chromosomes
w/ the centromeres near the ends) fuse at the centromere and the 2
short arms are lost.
◉ fragile X syndrome. Answer: X-linked defect affeccting the
methylation and expression of the FMR1 gene. Associated w/
chromosomal breakage. The 2nd most common cause of genetic
mental retardation (after Down syndrome). Trinucleotide repeat
disorder (CGG)
◉ copy number variation. Answer: the phenomenon of duplication
or deletion of segments of DNA within a genome, so that different
individuals have different numbers of copies of a particular DNA
segment
◉ aneuploidy. Answer: Abnormal number of chromosomes.
