GENETIC ANALYSIS CERTIFICATION EVALUATION EXAMS SET FULL QUESTIONS AND COMPLETE SOLUTION

GENETIC ANALYSIS CERTIFICATION
EVALUATION EXAMS SET FULL QUESTIONS
AND COMPLETE SOLUTION

●● Reverse genetics approaches begin...
Answer: ...with a gene sequence and seek to identify the corresponding
mutant phenotype


●● Saturation mutagenesis
Answer: Mutagenesis aimed at identifying multiple mutant alleles for all
loci in the genome of an experimental organism


●● Balancer chromosomes
Answer: Developed in Drosophila allow specific chromosomes to be
transmitted intact and followed through multiple generations


●● Permissive condition
Answer: Environmental condition in which environmentally sensitive
mutants exhibit the wild type phenotype or can survive


●● Restrictive condition
Answer: Environmental condition in which environmentally sensitive
mutants exhibit the mutant phenotype

,●● Modifier screen
Answer: To see if mutations in a second gene can enhance or suppress
the phenotype of the first mutation


●● Enhancer screen
Answer: Is a modifier screen in which mutations in a second site
enhance the phenotype of the initial mutant


●● Suppressor screen
Answer: Is a modifier screen designed to identify second site mutations
that suppress the phenotype of the initial genotype


●● Synthetic lethality
Answer: The situation where a particular double mutant results in
lethality but the two respective single mutants are viable


●● Genetic redundancy
Answer: The situation where the functions of one gene are compensated
for by the actions of another gene


●● Transgenes
Answer: Genes that have been modified in vitro by recombinant DNA
technology and introduced into the genome via transformation

,●● Transgenic organism
Answer: An organism harboring a transgene


●● Genomic libraries
Answer: A set of clones consisting of the DNA representing the genome
of an organism


●● Cloning vector
Answer: A piece of DNA derived from a plasmid, virus, or other
biological source that can be stably maintained in an organism and into
which heterologous pieces of DNA can be inserted


●● Bacterial artificial chromosome (BAC)
Answer: Cloning vector used in bacteria that utilizes the F plasmid
origin of replication; can accept DNA inserts up to 500kb


●● cDNA libraries
Answer: Collections of cloned DNA fragments that represent all the
mRNA produced by an organism. Only the portion of the genome that is
transcribed is represented in a cDNA library.


●● Transposon tagging

, Answer: Technique used to identify and clone genes through insertion of
a transposon into the target gene


●● Positional cloning (chromosomal walking)
Answer: The process by which the DNA sequence of a gene identified
only by mutant phenotype can be obtained by using genetic and physical
maps


●● Contiguous sequences (contigs)
Answer: Overlapping DNA clones that together cover an uninterrupted
continuous stretch of DNA sequence


●● Knockout libraries
Answer: Collections of mutants in which most or all genes of a
particular organism have been mutated by inactivating their expression


●● RNA interference (RNAi)
Answer: A regulatory gene silencing mechanism based on double
stranded RNA, which can target complementary sequence for
inactivation. The machinery can be harnessed to silence gene expression
in a reverse genetic approach.


●● Targeted induced local lesions in genomes (TILLING)