Campbell s Biology 9e Reece et al Chapter 15 The Chromosomal Basis of Inheritance Most new questions in this chapter are at the Application Analysis and Synthesis Evaluation levels Additional new questions test student knowledge of new material in the chapter In addition the chapter has been reorganized to place questions based on scenarios or figures at the end Multiple Choice Questions 1 When Thomas Hunt Morgan crossed his red eyed F1 generation flies to each other the F2 generation included both red and white eyed flies Remarkably all the white eyed flies were male What was the explanation for this result A The gene involved is on the Y chromosome B The gene involved is on the X chromosome C The gene involved is on an autosome but only in males D Other male specific factors influence eye color in flies E Other female specific factors influence eye color in flies Answer B Topic Concept 15 1 Skill Knowledge Comprehension 2 Sturtevant provided genetic evidence for the existence of four pairs of chromosomes in Drosophila in which of these ways A There are four major functional classes of genes in Drosophila B Drosophila genes cluster into four distinct groups of linked genes C The overall number of genes in Drosophila is a multiple of four D The entire Drosophila genome has approximately 400 map units E Drosophila genes have on average four different alleles Answer B Topic Concept 15 1 Skill Knowledge Comprehension 3 Which of the following is the meaning of the chromosome theory of inheritance as expressed in the early 20th century A Individuals inherit particular chromosomes attached to genes B Mendelian genes are at specific loci on the chromosome and in turn segregate during meiosis C Homologous chromosomes give rise to some genes and crossover chromosomes to other genes D No more than a single pair of chromosomes can be found in a healthy normal cell E Natural selection acts on certain chromosome arrays rather than on genes Answer B Topic Concept 15 1 Skill Knowledge Comprehension 1 Copyright 2011 Pearson Education Inc 4 Thomas Hunt Morgan s choice of Drosophila melanogaster has been proven to be useful even today Which of the following has have continued to make it a most useful species I II III IV its four pairs of chromosomes a very large number of visible as well as biochemically mutant phenotypes easy and inexpensive maintenance short generation time and large number of offspring A I and IV only B II and III only C I II and III only D II III and IV only E I II III IV and V Answer E Topic Concept 15 1 Skill Knowledge Comprehension 5 A woman is found to have 47 chromosomes including three X chromosomes Which of the following describes her expected phenotype A masculine characteristics such as facial hair B enlarged genital structures C excessive emotional instability D normal female E sterile female Answer D Topic Concept 15 2 Skill Application Analysis 6 Males are more often affected by sex linked traits than females because A male hormones such as testosterone often alter the effects of mutations on the X chromosome B female hormones such as estrogen often compensate for the effects of mutations on the X chromosome C X chromosomes in males generally have more mutations than X chromosomes in females D males are hemizygous for the X chromosome E mutations on the Y chromosome often worsen the effects of X linked mutations Answer D Topic Concept 15 2 Skill Knowledge Comprehension 7 SRY is best described in which of the following ways A a gene present on the X chromosome that triggers female development B an autosomal gene that is required for the expression of genes on the Y chromosome C a gene region present on the Y chromosome that triggers male development D an autosomal gene that is required for the expression of genes on the X chromosome E a gene required for development and males or females lacking the gene do not survive past early childhood Answer C Topic Concept 15 2 Skill Knowledge Comprehension 2 Copyright 2011 Pearson Education Inc 8 In cats black fur color is caused by an X linked allele the other allele at this locus causes orange color The heterozygote is tortoiseshell What kinds of offspring would you expect from the cross of a black female and an orange male A tortoiseshell females tortoiseshell males B black females orange males C orange females orange males D tortoiseshell females black males E orange females black males Answer D Topic Concept 15 2 Skill Application Analysis 9 Red green color blindness is a sex linked recessive trait in humans Two people with normal color vision have a color blind son What are the genotypes of the parents A XcXc and XcY B XcXc and XCY C XCXC and XcY D XCXC and XCY E XCXc and XCY Answer E Topic Concept 15 2 Skill Application Analysis 10 Cinnabar eyes is a sex linked recessive characteristic in fruit flies If a female having cinnabar eyes is crossed with a wild type male what percentage of the F1 males will have cinnabar eyes A 0 B 25 C 50 D 75 E 100 Answer E Topic Concept 15 2 Skill Application Analysis 11 Calico cats are female because A the males die during embryonic development B a male inherits only one of the two X linked genes controlling hair color C the Y chromosome has a gene blocking orange coloration D only females can have Barr bodies E multiple crossovers on the Y chromosome prevent orange pigment production Answer B Topic Concept 15 2 Skill Application Analysis 3 Copyright 2011 Pearson Education Inc 12 In birds sex is determined by a ZW chromosome scheme Males are ZZ and females are ZW A recessive lethal allele that causes death of the embryo is sometimes present on the Z chromosome in pigeons What would be the sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a normal female A 2 1 male to female B 1 2 male to female C 1 1 male to female D 4 3 male to female E 3 1 male to female Answer A Topic Concept 15 2 Skill Application Analysis 13 Sex determination in mammals is due to the SRY region of the Y chromosome An abnormality of this region could allow which of the following to have a male phenotype A Turner syndrome 45 X B translocation of SRY to an autosome of a 46 XX individual C a person with an extra X chromosome D a person with one normal and one shortened deleted X E Down syndrome 46 XX Answer B Topic Concept 15 2 Skill Application Analysis 14 In humans clear gender differentiation occurs not at fertilization but after the second month of gestation What is