Download 1. True or False? The standard human karotype consists of 23 pairs

1. True or False? The standard human karotype consists of 23 pairs of autosomes plus one pair of sex chromosomes. False 2. True or False? Reciprocal translocations result in abnormal gametes because they upset segregation. True 3. True or False? Duplication of the entire chromosome complement present in a species – or in a hybrid between species – is a major process in the evolution of higher plants. True 4. True or False? Genetically unbalanced chromosomal complements due to an extra or missing chromosome often have more severe effects on phenotype than does addition of genetically balanced set of chromosomes. True 5. True or False? Chromosome abnormalities are a rare factor in human spontaneous abortions and not a cause of genetic disorders. False 7. A chromosome with its centromere in the middle is A. submetacentric. B. metacentric. 9 C. acrocentric. D. telocentric. E. holocentric. 8. The master sex‐determining gene SRY that codes for the testis‐determining factor, resides on A. the X chromosome. B. one of the autosomes. C. the pseudoautosomal region of the X chromosome. D. the pseudoautosomal region of the Y chromosome. E. in the short arm of the Y chromosome, but out of pseudoautosomal region. 9 9. If polyploid species have complete sets of chromosomes from two or more different ancestral species, they are called A. allopolyploids. 9 B. autopolyploids. C. monoploids. D. aneuploids. E. euploids. 11. A chromosome in which the linear order of a group of genes is the reverse of the normal order, has a(n) A. duplication. B. deletion. C. translocation. D. inversion. 9 Page 1
E. position effect variegation. 12. Some XY individuals are phenotypically females. What chromosomal abnormality could account for this? A. Mosaicism B. Dosage compensation C. A deletion of the portion of the Y chromosome containing the testis‐determining factor. 9 D. Mitotic segregation E. Fragile X syndrome 13. 47, XXY is a condition known as A. Trisomy‐X syndrome. B. Klinefelter syndrome. 9 C. Turner syndrome. D. Double‐Y syndrome. E. Fragile X syndrome. 14. The evening primroses in the genus Oenothera have reciprocal translocations present in natural populations without the semisterility usually expected because A. segregation of chromosomes in meiosis is always in the alternate mode. 9 B. segregation of chromosomes in meiosis is always in the adjacent‐1 mode. C. segregation of chromosomes in meiosis is always in the adjacent‐2 mode. D. they are unable to reproduce sexually. E. they are polyploid. 15. The semisterility of genotypes that are heterozygous for a reciprocal translocation results from A. lethality due to the chromosomal abnormalities produced by alternate segregation. B. lethality due to the chromosomal abnormalities produced by adjacent‐1 segregation. C. lethality due to the chromosomal abnormalities produced by adjacent‐2 segregation. D. All of the above E. B and C 9 16. Turner syndrome is the result of A. trisomy of the X chromosome. B. the presence of an extra Y chromosome. C. the absence of a Y chromosome. D. monosomy of the X chromosome. 9 E. an extra chromosome number 13. 17. What percentage of recognized pregnancies in humans terminate in spontaneous abortion? A. 30% B. 15% 9 Page 2
C. 1% D. 5% E. Less than 1% 18. The products of crossing‐over within the paracentric inversion include A. submetacentric chromosome. B. Robertsonian translocation. C. a dicentric and an acentric chromatid. 9 D. two monocentric chromatids with deletions and duplications. 19. An event in which the centromeric regions of two non‐homologous acrocentric chromosomes become fused to form a singular centromere is known as a(n). A. reciprocal translocation. B. nonreciprocal transversion. C. Robertsonian translocation. 9 D. Louisian translocation. E. inversion. 20. A female marsupial expresses the X‐linked genes that she inherited from her mother because in marsupials A. the X chromosome inherited from the father is lost early in development. B. females are heterogametic, XY. C. females are always X0, and inherit sex chromosome from the mother. D. the inactivated X chromosome is always the one contributed by the mother. E. the inactivated X chromosome is always the one contributed by the father. 9 21. How many Barr bodies would be present in white blood cells of an individual with karyotype 48, XXYY? A. 0 B. 1 9 C. 2 D. 3 E. 4 22. Geneticist who described the inactivation of the X chromosome: A. Shawn Ahmed B. James Watson C. Mary Lyon9 D. Elizabeth Blackburn E. Jerome Lejeune 23. The chromosome designation 11p refers to Page 3
A. the long arm of chromosome 11. B. a partial deletion of chromosome 11. C. a specific band on chromosome 11. D. an inversion on chromosome 11. E. the short arm of chromosome 11. 9 25. Individuals that are heterozygous for a translocation produce A. the normal number of offspring. B. about one‐half as many offspring as normal. 9 C. about one‐fourth as many offspring as normal. D. about one‐tenth as many offspring as normal. E. no offspring. 26. The "calico" pattern of coat coloration in female cats is an example of A. random X chromosome inactivation. 9 B. position effect variegation. C. endoreduplication. D. a reciprocal translocation. E. trisomy of the X chromosome. 27. Euploidy is A. a chromosome number that is not an exact multiple of the haploid number. B. an example of aneuploidy. C. a chromosome number that is an exact multiple of the monoploid number. 9 D. the addition of an extra copy of a particular chromosome. E. the absence of a particular copy of a chromosome. Page 4