Chapter 22 & 24: Molecular/haplotype Mapping (Exam 3)

Question 1

three types of mapping

Answer 1

cytogenic, linkage, physical

Question 2

cytogenic mapping

Answer 2

relies on microscopy, use of dyes/fluorescence, genes mapped relative to bands on locations of chromosomes
crude maps, resolution of ~5 million bp

Question 3

linkage mapping

Answer 3

relies of frequency of recombination genetic crosses, genes mapped relative to each other, distances computed using map units

Question 4

physical mapping

Answer 4

relies on DNA cloning/sequencing techniques, genes mapped relative to each other, distances computed in number of base pairs between genes

Question 5

molecular marker

Answer 5

particular DNA segment that is found at specific site and can be uniquely recognized
should be polymorphic, interspaced throughout genome, often not part of gene

Question 6

Restriction Fragment Length Polymorphisms (RFLPs)

Answer 6

restriction enzymes recognize specific DNA sequences and cleave at those sequences
these enzymes will recognize many sites along a chromosome
will produce different fragments from different individuals

Question 7

Microsatellites / short tandem repeats (STRs)

Answer 7

short, repetitive sequences, abundantly dispersed throughout species’ genome, variable in length among individuals
inheritance pattern can be studies using PCR, amplified region called sequence tagged site (STS)
diploid cells will have two copies of an STS, same number of repeats gives single sized band, different number gives differently sized bands

Question 8

key difference between RFLPs and microsatellites

Answer 8

RFLPS used restriction enzymes and southern blot, difficult
Microsatellites use PCR, easy

Question 9

Haplotype

Answer 9

close linkage of alleles or markers on a single chromosome
variations between haplotypes can be used to distinguish pedigrees and indicate risk of genetic diseases