Question

5. Quantitative trait loci(QTL) are:

1. The loci that contribute all of the variation in a continuous trait
2. The loci that contribute all of the genetic variation in a continuous trait
3. The loci that contribute the broad-sense heritability in a continuous trait
4. The loci that contribute the narrow-sense heritability in a continuous trait

6. We looked at a study where Drosophila flies were selected for phototaxis (either attracted to or repelled by light). This experiment measures how much genetic variation existed in the original population and is known as a _________ study.

1. Response to selection
2. Selection
3. Selections differential
4. screening

7. You run a test cross involving two loci three times and think the results indicate the two loci are linked. The best way to verify this is to:

1. Repeat the experiment many more times
2. Analyze the data with the chi square test
3. Cross the loci with other loci on the chromosome
4. All of the above are correct

9. When running a two point (two loci) mapping cross:

1. The most common progeny classes are called parentals
2. The least common progeny classes are called recombinants
3. There should be two parental and two recombinant classes
4. All the above are true

10. A ¨hot spot¨ for genetic recombination is where:

1. The physical distance between loci matches the recombination frequency
2. The loci appear to be further apart as more than expected recombination is occuring
3. The loci appear to be closer together as less than expected recombination is occurring
4. Loci that are far apart on a chromosome may have 50% recombination between them

11. You suspect that genes a and b are linked but find that they assort independently you should:

1. Try crosses with each with loci that may be between them on the same linkage group
2. Realize that you were wrong and list them as being unlinked
3. Repeat the experiment until you get data that fits your expectations
4. None of the above are correct

12. The recombination frequency between two genes located far apart on the same chromosome cannot exceed?

1. 10% b. 25% c. 50% d. 100%.  

   15. Which of the following is a key aspect of the Hershey-Chase bacteriophage experiments?a)If DNA is destroyed cells are not transformed only smooth bacteria kill mice

2. Labeling of components 32p only into DNA: only 32p enters cells and is passed on to progeny
3. if RNA is destroyed cells are transformed rough bacteria do not kills mice
4. all of the above are correct. 16. The two major functions of nucleosomes are best represented as: a)Compacting the genome and access for replication and gene expression b)Compacting the genome protecting genome against damage c)Compacting the genome and proper genome segregation during cell division d)Protecting the genome against damage and access for reliction an expression

   19. When examining centromere sequences for a specific eukaryote one finds: a)They all are a simple repeat sequence b)All the chromosomes have a similar(consensus) sequence in their centromeres c)Centromere sequences are quite different from one chromosome to the next d)No specific sequence has been found to represent a centromere

   21. When looking at the organization and content of the human genome all of the following are true, EXCEPT:

5. Twice as much of the genome is microsatellites(STR) compared to gene sequence
6. Gene related sequences, such as introns, make up about a third of the genome
7. Genome wide repeats make up nearly a third of the genome
8. Genes represent about 10% of the genome

   24. You use PCR analysis on DNA from a couple and their developing fetus to screen for a genetic defect. You find that both parents have one large and two small DNA bands, while the fetus has only the large DNA band. The most likely explanation for these results is :

9. The infant is a heterozygote and the parents are both homozygotes
10. All three are heterozygotes
11. Both parents are heterozygotes, the fetus is a homozygote
12. You can not tell the allele combinations for the three individuals 25. Linus Pauling and coworkers used gel electrophoresis of hemoglobin to:
13. Show that red cells have lots of hemoglobin
14. To show heterozygotes could be told apart from homozygotes for HbA and HbS
15. Show hemoglobin is made up of two subunits
16. Show that the a-globin and b-globin genes are linked 26. For genetic testing of a developing embryo, of the following procedures identify the one that is less likely to cause health issues in the individuals being tested?
17. Amniocentesis
18. Isolating and analyzing DNA/RNA from the mother’s blood
19. Chorionic villus sampling
20. None of the procedures present a significant health risk

    28. You are analyzing mutants that are defective in the synthesis of the amino acid tryptophan and isolate fifty-five of these mutants. You cross each of the mutants to each other and find five complementation groups. Your results suggest that there are_______ steps in the biochemical pathway to tryptophan.

21. One
22. Three
23. Five
24. six

Answer 1

5 number question answer is b that is The loci that contribute all of the genetic variation in a continuous trait.

6 number question answer is b that is Selection.

7 number question answer is c that is Cross the loci with other loci on the chromosome.

28 number question answer is W that is Five.

24 number question answer is s that is Chorionic villus sampling.(Chorionic villus sampling (CVS) is a prenatal test that is used to detect birth defects)

21 number question answer is h that is Genes represent about 10% of the genome(some genes are over-represented and a few may be more than 10%)

19 number question answer is a that is They all are a simple repeat sequence.

12 number question answer is c that is 50%.

15 number question answer is b that is Labeling of components 32p only into DNA: only 32p enters cells and is passed on to progeny

16 number question is b that is Compacting the genome protecting genome against damage

10 number answer is c that is The loci appear to be closer together as less than expected recombination is occurring

9 number question answer is c that is There should be two parental and two recombinant classes

11 number correct answer is d that is None of the above are correct