Genetics Entrance Questions

Genetics entrance questions 1. _____ What would be the dimensions of a Punnett square for the cross Ww x ww?

A. 4 x 4B. 2 x 2C. 2 x 1D. 1 x 1

2. _____ In dihybrid crosses, the ratio 9:3:3:1 indicates ___.

A. CodominanceB. Independent assortment C. Intermediate dominanceD. Three alleles for each trait 3. _____In a cross of a round hybrid pea with a true breeding round parent (Ww x WW), what genotypic proportions would be observed in the offspring? A. Half heterozygous, half homozygous dominant B. Half round, half wrinkledC. All heterozygousD. All round 4. _____ The fundamental Mendelian process which involves the separation of contrasting genetic elements at the same locus would be called ___. A. segregationB. independent assortmentC. continuous variation D. discontinuous variationE. dominance or recessiveness 5. _____There are three different genotypes resulting from a monohybrid cross. How many different genotypes would there be resulting from a dihybrid cross? A. 4B. 8C. 9D. 16

6. _____ Starting with a cross between AA and aa, the proportion of heterozygotes in the F2 progeny will be ___. A. 1/8B. 1/4C. 1/3D. 1/2E. All heterozygotes 7. _____ Genotype is to DNA as phenotype is to A. GenotypeB. ProteinsC. ExpressivityD. RNAE. Mutation

8. _____ Starting with a P generation with the following genotypes (AABB x aabb). Based on classical Mendelian inheritance, what is the expected phenotypic ratio observed among the F2 progeny?

A. 9:3:3:1B. 1:2:1C. 3:1D. 1:1E. 1:1:1:1 9. Mendal’s work was rediscovered in: a.1869 b. 1899 c. 1920 d. 1900 10. Down’s syndrome is caused due to a. Monosomy of 21st b. Disomy of 21chromosomest c. Trisomy of 21chromosomest d. An extra X chromosome in female chromosome 11. X shaped structure a. Chiasma b. Gene c. DNA d. RNA 12. What type if allele produces its effects only in homozygous individuals? a. Recessive b. Dominant c. Incomplete recessive d. None of the above 13. In male fruit flies white eyes are determined by a a. Recessive gene on Y b. Recessive gene on X c. Dominant gene on X d. Dominant gene on Y 14. When alleles move into different gametes, it shows the a. Dominance b. Incomplete dominance

c. Segregation d. Crossing over 15. Mendel’s experimental plant is a. sweet pea b. garden pea c. sweet potato d. wild pea 16. The ABO blood groups in human is the example for a. dominance b. recessive c. Incomplete dominance d. Codominance 17. Turner’s syndrome is caused due to a. presence of extra X chromosome in male b. absence of one of the X chromosome in male c. absence of one of the X chromosome in female d. Presence of one extra chromosome in female. 18. Langdon Down first reported the disease called a. Down’s syndrome b. Klinefelters syndrome c. Turner’s syndrome d. Sickle cell anemia 19. Sickle cell anemia caused by the presence of mutantallele in ----chromosome a. seventh b. eighth c. tenth d. eleventh 20. Symptom of Turner’s syndrome are a. webbed neck b. sterility c. poor development of breasts d. All the above. 21. One map unit is equal to -----percent of recombination a. 1 b. 2 c. 3 d. 4 22. Genotype Tt represents the phenotype of a. tall b. dwarf c. Both a and b d. None of the above. 23. ----proposed the chromosomal theory of the inheritance a. Sulton b. Boveri c. Down d. Both a and b e. Both a and c 24. ----pairs of chromosomes are present in drosophila fly. a. 2 b. 3 c. 4 d. 5 54. How many autosomes are found in a single mature human sperm. a. 20 b. 21 c. 22 d. 23 25. –--------is the phenotypic and genotypic ratio of incomplete dominance. a. 1: 1: 1 b. 1: 2: 1 c. 1:2:2 d. 2:2:2 26. Find the Mendelian disorders that are sex linked. a. Haemophilia b. Colour blindness c. Both a and b d. None of the above. 27. Who was the first map to chromosomes? a. Alfred Sturtevant b. Slton c. Down d. Mendel 28. Female has-----chromosome a. XX b. XY c. XXY d. YYY 29. Genetic constitution of an organism a. Phenotype b. Genotype c. Dihybrid d. Monohybrid 30. Different forms of gene a. chromosome b. alleles c. linkage d. all the above 31. In a simple Mendelian monohybrid cross, tall plants were crossed with short plants and the F1 were crossed among themselves. What fraction of the F2 generation are both tall and heterozygous? a. 1 ⁄8 b. 1⁄4 c. 1⁄3 d. 2⁄3 e. 1⁄2 32. The phenotype of an individual a. depends at least in part on the genotype. b. is either homozygous or heterozygous. c. determines the genotype. d. is the genetic constitution of the organism. e. is either monohybrid or dihybrid. 33. The ABO blood groups in humans are determined by a multiple allelic system where IA and IB are codominant and dominant to IO. A newborn infant is type A. The mother is type O. Possible genotypes of the father are: a. A, B or AB b. A, B or O c. O only d. A or AB e. A or O 34. Which statement about a test cross is not true? a. It tests whether an unknown individual is homozygous or heterozygous. b. The test individual is crossed with a homozygous recessive individual. c. If the test individual is heterozygous, the progeny will have a 1:1 ratio. d. If the test individual is homozygous, the progeny will have a 3:1 ratio. e. Test cross results are consistent with Mendel’s model of inheritance. 35. Linked genes a. must be immediately adjacent to one another on a chromosome. b. have alleles that assort independently of one another. c. never show crossing over. d. are on the same chromosome.

e. always have multiple alleles. 36. In the F2 generation of a dihybrid cross a. 4 phenotypes appear in the ratio 9:3:3:1 if the loci are linked. b. 4 phenotypes appear in the ratio 9:3:3:1 if the loci are unlinked. c. 2 phenotypes appear in the ratio 3:1 if the loci are unlinked. d. 3 phenotypes appear in the ratio 1:2:1 if the loci are unlinked. e. 2 phenotypes appear in the ratio 1:1 whether or not the loci are linked. 37. The sex of a human is determined by a. ploidy, the male being haploid. b. the Y chromosome. c. X and Y chromosomes, the male being XY. d. the number of X chromosomes, the male being XO. e. Z and W chromosomes, the male being ZZ.