Genetics - 2005

1.  Which of the following would be the percentage of women with a recessive disease attached to the X, when the amount of defected alleles in the population is 1%?

  1. 0.01%.
  2. 0.1%.
  3. 10%.
  4. 20%.
  5. 50%.

2.  In a certain population, the percentage of homozygotes in allele A is 28%. The percentage of homozygotes in allele B is 8%. Which of the following is likely if A and B are both of the same gene?

  1. There is a selective preference for homozygosity in allele A.
  2. There is a selective preference for homozygosity in allele B.
  3. There is a selective preference for heterozygosity.
  4. There is insufficient data to determine.

3.  The diagram below shows a couple who have had a baby that has a rare recessive disease, whose gene sits on chromosome 11. The gene itself is unknown, but a polymorphic marker attached to it is known, and has been genetically mapped. The family would like to know if the next baby will be sick. They have been told it will not, and in reality it did come out sick. Which of the following has gone wrong?

  1. A mistake in the test caused the identification of GATA(16) instead of GATA(18) in the fetus.
  2. The nurse who did the test switched the DNA of the fetus with that of another.
  3. The gene is not on chromosome 11.
  4. During the mother’s meiosis there was a recombination between the polymorphic marker and the gene carrying the disease.

4.  Which of the following is true in relation to insufficiency mutations in the genes?

  1. An insufficiency of 5 bases will always cause a change in the open reading frame.
  2. An insufficiency of 5 bases will not always cause a change in the open reading frame.
  3. An insufficiency of 9 bases will never cause a change in the open reading frame.
  4. An insufficiency of 9 bases will always cause a change in the open reading frame.

5.  Which of the following is STS?

  1. Polymorphic marker.
  2. A unique site in the genome.
  3. A repeating sequence in the genome.
  4. A regulatory gene (does not code protein).

6.  Which of the following is proteomics?

  1. A research which deals in matching medicine with patients based on their genotype.
  2. A research of the whole layout of proteins which are coded by the same genome.
  3. Comparing different proteins with different creatures in evolution.

7.  Which of the following is true?

  1. A somatic mutation is never hereditary.
  2. A somatic mutation can be hereditary.
  3. A mutation in the germ-line is always hereditary.
  4. A mutation in the germ-line is never hereditary.

8.  Which of the following describes the difference between exon and introns?

  1. Exons are in the mature mRNA and introns aren’t.
  2. Exons are coded for proteins and introns aren’t.
  3. Exons are in the mature mRNA and introns in the pre mRNA.
  4. Exons are displaces and introns aren’t.

9.  Which of the following is related to differences in polymorphic sequences?

  1. Never in a sequence coded for protein.
  2. Can appear in sequences coded for protein but not influence the composition of its amino acids.
  3. Can appear in sequences coded for protein and influence the composition of its amino acids but not its function.
  4. Can appear in sequences coded for protein as well as influence the composition of its amino acids and its function.

10. Which of the following is 3’UTR?

  1. The sequence between the point of the beginning of the displacement and the point of the beginning of the translation.
  2. The sequence between the point of the end of the displacement and the point of the end of the translation.
  3. The sequence between the point of beginning of the displacement and the point of the end of the displacement.
  4. The sequence between the point of beginning of the translation and the point of the end of the translation.

11. In which of the following cases, will you not perform a karyotype?

  1. A baby with only a cleft palate.
  2. A 17 y/o girl who didn’t receive a period.
  3. A fetus, in which an amniotic fluid test has discovered a balanced chromosomal translocation.
  4. A baby with a large number of defects.

12. Please match the following tests with the corresponding people:

1. CVS / a. A healthy 35 y/o woman in her 15th week of pregnancy.
2. Amniotomy / b. A healthy 25 y/o woman who works in special care, first pregnancy and concerned with down syndrome.
3. Ultrasound - system survey. / c. A woman in her 16th week of pregnancy with abnormal findings during a system survey.
4. Fetal protein test. / d. A woman who has in a previous pregnancy a baby with severe heart defects, abnormal joints and abnormal number of fingers. Baby’s karyotype was normal.
5. Fetal blood test from the umbilical. / e. A couple which both are CF carriers and there is a risk of the disease in the family.

13. Please match the following:

1. 23,X / a. Haploidy.
2. 69,XXX / b. Aneuploidy.
3. 46,XX / c. Tetraploidy.
4. 47,XY,21+ / d. Triploidy.
5. 92,XXXX / e. Diploidy.

14. Please match the following:

1. A phenomenon which happens in healthy males and not in healthy females. / a. Genomic impression.
2. A phenomenon which happens in healthy females and not in healthy males. / b. Chromosome X inactivation.
3. A phenomenon that causes a phenotypical mosaic in healthy individuals. / c. Both.
4. A phenomenon which causes random gene inexpression from the paternal allele as well as the maternal allele. / d. Neither.

15. Please match the following:

1. Can be expressed in a normal cell of a healthy person. / a. Oncogenes or protoncogenes
2. Can be activated by translocation and breaks. / b. Tumor suppressors
3. Without their activity, the cell can easily become cancerous. / c. Both.
d. Neither.

16. The following is the process that determines the pigment in mouse fur: A colorless base pigment is transformed to a colorless intermediate product by enzyme A, coded by gene A. The intermediate product is transformed to a brown pigment by enzyme B, coded by gene B. The brown pigment is transformed to a black pigment by enzyme C, coded by gene C. The alleles of A,B and C are dominant. A crossbreeding experiment was performed to the race of AABBCC, and then they crossbred F1 with themselves. Which of the following would be the phenotype ratio in F2?

  1. 9 black, 3 brown, 1 white.
  2. 27 black, 9 brown, 28 white.
  3. 13 black, 2 brown, 1 white.
  4. 27 black, 9 brown, 3 white.
  5. None of the above.

17. Which of the following is the maximum length of the chromosome 3 in humans, if you find an average of 3.75 chiasmas per bivalent?

  1. 3.75.
  2. 375.
  3. 1.875.
  4. 187.5.

18. In a test crossbreeding of a BR/br fly, 84% of the meiosis have no chiasma, and 16% of the meiosis have a single chiasma. Which if the following is the change to get a bbrr offspring?

  1. 4%.
  2. 46%.
  3. 16%.
  4. 84%.

19. Rachel and Sarah, Jacob and Isaac are two sets of identical twins. Rachel marries Jacob, Sarah marries Isaac. Each couple has a single child. The two children will be genetically similar as which of the following?

  1. Cousins.
  2. Identical twins.
  3. Siblings.
  4. It is not possible to know.

20. In a specific chromosomal area, the correlation is more than 1. Which of the following is the number of double recombinations in this area?

  1. 0.
  2. Lower than expected by the rate of unique recombinations in this area.
  3. Higher than expected by the rate of unique recombinations in this area.
  4. Equal to the expected by the rate of unique recombinations in this area.

21. A man and a woman who have the same genotype AaHHTkBb are married. Which of the following is the probability that their first child will have an AaHHKKBB genotype?

  1. 1/4.
  2. 3/4.
  3. 1/16.
  4. 3/32.
  5. 1/32.

22. In a woman the recombination rate between genes A and B is 8%, while in a man its 5%. Which of the following is the chance to get an AABB offspring from a coupling of a man and a woman, both of which are AaBb?

  1. 4%.
  2. 21.8%.
  3. 25%.
  4. 40%.
  5. 92%.

23. In the gene Ee, a mutation (e) is causing a severe phenotype at the rate of 0.6 in its homozygotic shape. Which of the following is the ratio of defected:healthy in an EexEe crossbreeding?

  1. 3:1.
  2. 6:4.
  3. 45:44.
  4. 85:15.
  5. 9:1.

24. 6% of all meiosis in AB genes in a mouse have recombinations. Which of the following is the distance between genes A and B?

  1. 6cM.
  2. 12cM.
  3. 30cM.
  4. 2cM.

25. Which of the following is the distance between two genes with the same chromosome, in which 6% of their meiosis have a chiasma?

  1. 3cM.
  2. 6cM.
  3. 12cM.
  4. 30cM.

26. What is polyadenylation?

27. What is the definition of genetic heterogeneity?

28. Which of the following is not required by a protein level genetic test?

  1. Knowledge of the chromosomal location of the mutated coded gene.
  2. Knowledge of the location of the mutated protein.
  3. Knowledge of the biological activity of the mutated protein.
  4. Existence of a biochemical test to measure the activity or level of the mutated protein.

29. What does a cloning vector always include?

30. What is BAC?

31. Which of the following is true in relation to mitochondrial DNA?

  1. It is similar to virus DNA.
  2. It does not contain introns.
  3. It is about 10% of total cellular DNA.
  4. It has only 250 genes.
  5. It is more stable than nuclear DNA.

32. Which of the following statements describes correctly a high resolution chromosomal analysis?

  1. You can identify genes that have only one copy.
  2. Is performed at the end of the metaphase of cellular mitosis.
  3. Can identify 400 light and dark stripes.
  4. Is used to locate broken areas in the genes.
  5. Can identify small structural changes in the chromosomes.

33. Which of the following describes a genetic mosaic?

  1. DNA that is composed of 4 types of bases.
  2. A chromosome composed of DNA and RNA.
  3. A protein is created from information in at least two genes.
  4. A protein system created from information in two genomes.
  5. A gene that donates information to at least two proteins.

34. Which of the following statements best describes chromosomal changes in cancerous growths?

  1. Are usually unique and are characterized by the type of the growth.
  2. These changes are usually in every cell in the body.
  3. These changes usually disappear as the growth becomes more malignant.
  4. The changes are usually different within each of the growth’s cells.

35. Hereditary colon cancer with no polyps is a great risk for the appearance of malignant growths and is a dominant autosomal inheritance. Which of the following is not inherited by people with it?

  1. Activated Oncogen.
  2. Immune deficiency disease.
  3. Abnormal metabolism of carcinogenic substances.
  4. Chromosomal aberration.
  5. A defect in a DNA repair mechanism of the mismatch repair type.

36. The usage of drugs to effect changes in gene activity has become more popular lately. An example is the administration of hydroxyurea to patients with sickle-cell anemia. Which of the following describes the effect of hydroxyurea?

  1. Stimulates the defected gene to work harder.
  2. Repairs the mutation by causing a new mutation.
  3. Activates a normally inactive gene.
  4. Increases the amount of RNA.
  5. Repairs the defected gene.


Genetics - 2003

1.  Chickens with the genotype HhBb have been crossbred with chickens with the genotype HHbb. Which of the following odds is that the offspring will be homozygotic in HB loci?

a.  30%.

b.  50%.

c.  23%.

d.  75%.

2.  Which of the following is not true?

a.  All vertebrates have an XY mechanism to determine sex.

b.  Dosage-compensation exists in all creatures with heteromorphic chromosomes in one of the sexes.

c.  There is a mechanism of inactivation or hyperactivation in females.

d.  a and b.

e.  a and c.

f.  a, b and c.

3.  The following statements are given:

I.  A recessive disease attached to the X passes from a sick father to his son.

II.  A recessive autosomal disease passes from a sick father to his daughter and the mother is not a carrier.

III. A recessive autosomal disease passes from a carrying father to his son and the mother is not a carrier.

IV. A recessive autosomal disease passes from a carrying father to his daughter and the mother is not a carrier.

Which of the above can be described by isodisomy?

a.  All of them.

b.  I.

c.  I and II.

d.  III and IV.

e.  II, III and IV.

4.  Which of the following is true in relation to the following diagram, and assuming an attachment to chromosome X?

a.  Subject 1-II exhibits a dominant disease.

b.  1-I and 2-II are carriers for the phenotype observed in 1-II.

c.  The probability that another offspring of 2-II and 3-II will have the same phenotype of 1-III is 0.5.

d.  If 1-II will marry a woman with an identical phenotype of his sister, 75% of their offspring is expected to have the same phenotype as their aunt.

e.  This family line does not correspond to a disease attached to the X.

5.  In a crossbreeding between male and female fruit flies which seemed totally normal have given the results of 68 males and 141 females. Which of the following is not true?

a.  The number of offspring deviates from the expected in the male:female ratio.

b.  The female is in a heterozygote crossbreeding to a lethal allele attached to the sex.

c.  The male is a heterozygote crossbreeding to a dominant allele of the same gene.

d.  From the results you can conclude it is a pleiotropic gene.

6.  Which of the following is the disease described in the given diagram?

a.  Recessive autosomal.

b.  Dominant autosomal.

c.  Recessive attached to the X.

d.  Dominant attached to the X.

7.  A couple is heterozygote to a recessive mutation that causes albinism. The woman is pregnant with unidentical twins. Which of the following is the probability both twins will have the same pigmentation phenotype?