Chapter 15: The Chromosomal Basis Of Inheritance
Biology, 7e (Campbell)
Chapter 15: The Chromosomal Basis of Inheritance
Chapter Questions
1) Chromosomes and genes share all of the following characteristics except that
A) they are both present in pairs in all diploid cells.
B) they both undergo segregation during meiosis.
C) their copy numbers in the cell decrease after meiosis, and increase during fertilization.
D) they are both copied during the S phase of the cell cycle.
E) they both pair up with their homologues during prophase of mitosis.
Answer: E
Topic: Concept 15.1
Skill: Knowledge
2) The improvement of microscopy techniques in the late 1800s set the stage for the emergence of modern genetics because
A) it revealed new and unanticipated features of …show more content…
Wild type (heterozygous for normal wings and red eyes) × recessive homozygote with vestigial wings and purple eyes
74) What pattern of inheritance would lead a geneticist to suspect that an inherited disorder of cell metabolism is due to a defective mitochondrial gene?
Answer: The disorder would always be inherited from the mother.
75) Women born with an extra X chromosome (XXX) are healthy and phenotypically indistinguishable from normal XX women. What is a likely explanation for this finding? How could you test this explanation?
Answer: The inactivation of two X chromosomes in XXX women would leave them with one genetically active X, as in women with the normal number of chromosomes. Microscopy should reveal two Barr bodies in XXX women.
76) Determine the sequence of genes along a chromosome based on the following recombination frequencies: A-B, 8 map units; A-C, 28 map units; A-D, 25 map units; B-C, 20 map units; B-D, 33 map units.
Answer: D-A-B-C
77) Assume that genes A and B are linked and are 50 map units apart. An animal heterozygous at both loci is crossed with one that is homozygous recessive at both loci. What percentage of the offspring will show phenotypes resulting from crossovers? If you did not know that genes A and B were linked, how would you interpret the results of this
Chapter 15: The Chromosomal Basis of Inheritance
Chapter Questions
1) Chromosomes and genes share all of the following characteristics except that
A) they are both present in pairs in all diploid cells.
B) they both undergo segregation during meiosis.
C) their copy numbers in the cell decrease after meiosis, and increase during fertilization.
D) they are both copied during the S phase of the cell cycle.
E) they both pair up with their homologues during prophase of mitosis.
Answer: E
Topic: Concept 15.1
Skill: Knowledge
2) The improvement of microscopy techniques in the late 1800s set the stage for the emergence of modern genetics because
A) it revealed new and unanticipated features of …show more content…
Wild type (heterozygous for normal wings and red eyes) × recessive homozygote with vestigial wings and purple eyes
74) What pattern of inheritance would lead a geneticist to suspect that an inherited disorder of cell metabolism is due to a defective mitochondrial gene?
Answer: The disorder would always be inherited from the mother.
75) Women born with an extra X chromosome (XXX) are healthy and phenotypically indistinguishable from normal XX women. What is a likely explanation for this finding? How could you test this explanation?
Answer: The inactivation of two X chromosomes in XXX women would leave them with one genetically active X, as in women with the normal number of chromosomes. Microscopy should reveal two Barr bodies in XXX women.
76) Determine the sequence of genes along a chromosome based on the following recombination frequencies: A-B, 8 map units; A-C, 28 map units; A-D, 25 map units; B-C, 20 map units; B-D, 33 map units.
Answer: D-A-B-C
77) Assume that genes A and B are linked and are 50 map units apart. An animal heterozygous at both loci is crossed with one that is homozygous recessive at both loci. What percentage of the offspring will show phenotypes resulting from crossovers? If you did not know that genes A and B were linked, how would you interpret the results of this