Chapter 7: Linkage
1. What is linkage? When does it occur? Which of Mendel's laws is violated if two genes are linked?

2. How does crossing over break up linkage?

3. What structures actually go through crossing over?

4. If a test cross is performed, what phenotype ratio would you see? Which of the phenotypes would be recombinant and which would be non-recombinant? If linkage is suspected, how would it change those numbers?

5. Why, if you performed a testcross, could the percentage of recombinant offspring not exceed 50%?

6. Be prepared to do the following:
-Determine which progeny is recombinant and which is non-recombinant.
-Use chi-square to determine from the data whether linkage exists
-Use the data to map out the order of genes on a chromosome
-Write down the example presented in class here.

7. What is the difference between a single and a double cross-over event as well as their effect on progeny phenotype ratios?

Chapter 8: Chromosomal Variation
1. To what extent does a variation in chromosome number and structure affect phenotype?

2. What is the name of the field where scientists study chromosomes?

3. How are chromosomes referred to based on centromere position?

4. What is G banding? Can it reveal DNA sequence differences?

5. Define:
a. Deletion
b. Duplication
c. Inversion
d. Simple translocation
e. Reciprocal translocation

6. What is cri-du-chat syndrome?

7. When (or wherein a chromosome) are duplications more likely to occur? Why?

8. What is a gene family?

9. Define:
a. Homologous genes:
i. Paralogs:
ii. Orthologs
iii. Example: answer this - what would you call hemoglobin gene of a human vs.
Hemoglobin gene of a mouse? How about human fetal hemoglobin vs. adult
human hemoglobin?

10. What is copy number variation?

DNA Structure Lecture Questions
2. Griffith experiment: what did it demonstrate? What organisms were used in the experiment? How was the main principle demonstrated with the results?

3. Avery, Mcleod, and McCarty: what was their experiment and what did it demonstrate?

4. Hershey and Chase: How did they use isotope-labeled phosphorus and sulfur to show it was DNA, not proteins, that contained information?

5. Structure of DNA:
a. Chemical composition:
b. Physical shape
c. Types of bonds (connecting nucleotides as well as between double strands
d. Types of nucleotides, and what they resemble

6. Compare and contrast DNA and RNA

7. What is Chargaff s rule? Be sure to know how to apply it on an exam.

8. Who were Franklin, Watson, and Crick? State their findings in detail.

9. What else can you add about the structure of DNA based on their discovery?

Chapter 12: Chromosomal Organization
1. Describe the size and shape of, bacterial chromosomes.

2. What are protein-encoding genes vs. intergenic regions?

3. In bacteria, is there direct contact between DNA and cytoplasm?

4. How much do bacterial chromosomes compact?

5. What is DNA supercoiling?

6. What is negative supercoiling?

7. What are the roles of DNA gyrase (topoisomerase II) and DNA topoisomerase I?

8. How do drugs like quinolones and coumarin work? Give an example:

9. Describe origins of replication, centromeres, and telomeres in eukaryotes.

10. How, many genes are on a chromosome?

11. What are introns?

12. What are DNA repetitive sequences? Describe three main types of DNA sequences?

13. What is the difference between interspersed sequences and tandem arrays?

14. How long is a stretched-out chromosome?

15. What is chromatin?

16. What is a nucleosome? What is it made up of?

17. What are the "beads on a string" model of DNA sequence folding/

18. Describe the chemistry of histone proteins and how they bind. What else binds to them and why?

19. What is the Kornberg model and how was it tested with DNAse? Know this experiment.

20. What is 30-nm fiber? By the end of compaction, how compacted is DNA?

21. What are chromosome territories?

22. What is the differerce betr,r,een hcterocluoi-nalin ancl euchromatin?

23. Chromosomes are most condensed during………………?

11. What is the difference between pericentric and paracentric inversions?

12. What causes chromosomal translocations?

13. When it comes to reciprocal translocations, what is the difference between balanced and unbalanced?

14. What is a Roberlsonian translocation?

15. Define:
a. Aneuploidy:
i. Trisomy:
ii. Monosomy:
b. Euploidy:

16. What percentage of spontaneous abortions are due to chromosomal abnormalities?

17. Why can sex chromosome aneuploidies generally have less severe symptoms?

18. What is the term for improper segregation of chromosomes during meiosis I?

19. Is polyploidy common in animals? Plants?

20. What is endopolyploidy?

21. What are polytene chromosomes?

22.Why might scientists be interested in creating polyploids with an odd number of chromosome Sets?

23.Define meiotic nondisjunction?

24. What percent gametes would be abnormal if nondisjunction occurred in meiosis I vs. II

25. Define autopolyploidy, allopolyploidy, and allopolyploidy:

26. What is colchicine and what is it used for?

8. State the lonnula for calculating distance between two genes from recombination frequency' and provide au example?

9. Is both meiotic and mitotic recombination possible?

Chapter 7: Linkage 1. What is linkage? When does it occur? Which o...