Genetic Engineering Exam Paper

Spring 2017 AGRON 680 NAME:
Exam III - 100 pts

1) Describe the difference between ‘sticky-ends’ and ‘blunt-ends’ produced using restriction enzymes. (5 pts)

2) A sample of DNA consisted of 20% guanine. What are the names and percentages of the other three nitrogenous bases. (5 pts)

3) Why are selection of promoters important in genetic engineering? (10 pts)

4) Describe one example of a specific promoter used in plant biotechnology? (5 pts)

5) Describe the difference between a genetic map and a physical map. (10 pts)

6) Why is the genetic map length not changing in the middle (box in the center) when the physical map length is increase? (10 pts)

7) Low-copy and gene rich regions of the genome are usually not recombination hot spots. True or False? (5 pts)

8) Briefly
define monomorphic in relation to genetic markers. (5 pts)

9) Describe the difference between a co-dominant versus dominant genetic marker. (5 pts)

10) The following banding pattern was observed for an SSR marker run on two parents (A and B) and recombinant inbred line progeny from a cross between the two parents.

Does this banding pattern show a dominant or co-dominant marker? (2 pts)
Explain your answer. (5 pts)

11) A SNP was identified with a T poly morphism at a site that is normally G. An assay was designed to tag the T allele with the florescence molecule FAM and the G allele with the florescence molecule VIC. In the following graph 100 samples were genotyped, each represented by a single point. For each of the four clusters, label the GENOTYPE represented by that respective cluster. (8 pts)

12) What is golden rice and what was the main reason for creating it?
What is its status with regard to commercial development? Describe one concern related to using golden rice? (10 pts)

13) A lod score is a: (5 pts)
a) Measure of the genetic diversity in a population
b) Measure of the number of loci on the chromosomes
c) Measure of the probability of linkage between two loci
d) Measure of the average distance between molecular markers

14) Two-point test crosses revealed the following map results: tc___________me 25 map units me___________at 12 map units

A. Draw the two possible maps for these three loci. (5)

B. What cross could you make that would resolve the two possible maps and what are the possible outcomes of that cross? (5)

EXTRA CREDIT (9 pts)

A soybean plant with the genotype TTDD is crossed to a plant that is homozygous ttdd and then the F1 progeny are self-pollinated. What percentage of the F2 progeny will be ttdd if the two genes (loci) are:

a) Unlinked

b) Completely linked

c) 20 map units
apart