Concept explainers
To review: The fact that “inversions and reciprocal translocations are less lethal than aneuploidy, duplication, deletions and nonreciprocal translocation”.
Concept introduction: The aberration in chromosome structure and function can be caused due to aneuploidy, duplication, deletions and translocations. These can alter the chromosome to cause genetic disorders. Aneuploidy is a type of chromosomal alteration in which the number of chromosome changes. Duplication refers to the repetition of a segment on the chromosome. Deletion is the removal of a segment of a chromosome and the translocation is the transfer of a segment from one locus to another locus on the chromosome. Inversion is the insertion of a segment of chromosome in reverse order.
Want to see the full answer?
Check out a sample textbook solutionChapter 15 Solutions
CAMPBELL BIOLOGY,VOL.II >CUSTOM<
- What mechanisms are responsible for: (a) duplication of a chromosome segment; (b) generation of a Down syndrome individual; (c) a chromosome translocation; and (d) polyploidy?arrow_forwardA geneticist discovers that a girl with Down syndrome has a Robertsonian translocation involving chromosomes 14 and 21. If she has an older brother who is phenotypically normal, what are the chances that he is a translocation carrier?arrow_forwardWhat is pseudodominance and how is it produced by a chromosome deletion?arrow_forward
- A diploid individual is heterozygous for a chromosome rearrangement. The original chromosome and its rearranged homolog have the following segments, where ∙ represents a centromere: A B ∙ C D E F G A B ∙ C F E D G While paired in prophase I, a single crossing-over occurs between segment E and segment D of the paired chromosomes. Describe the unusual crossing-over structure that forms as a result.What gamete types will result from crossing over when meiosis is complete? please asaparrow_forwardWhat is the most common autosome aneuploidy?arrow_forwardA normal mother has translocations on chromosomes 14:21. With respect to chromosomes 14:21, how many combinations of chromosomes are possible? How many gametes are viable? If the woman has children with an normal father, what is the probability that there is a daughter with Down Syndrome or a son with an unaffected phenotype?arrow_forward
- Why are the X and Y chromosomes not considered homologous even though they recombine at the PAR region?arrow_forwardChromosome structural errors can occur during Meiosis which can lead to health disorders. Examine the figure below and select the correct order of error type from left to right in which they appear. duplicati on, translocation, deleti on, inversion duplication, inversion, del etion, translocation O deletion, translocati on, inversion, duplication O translocation, inversion, duplication, deletion inversion, translocation, duplication, deletionarrow_forwardInversions are known to affect crossing-over. The following homologs have the indicated order (the filled and open circles indicate centromeres): • (A B C D E) o (A D C B E) b. Diagram the alignment of these chromosomes during meiosis.arrow_forward
- Why are people with balanced chromosomal translocations phenotypically normal? Do they suffer from reduced fertility? Why?arrow_forwardTurner’s syndrome is the most common sex chromosome aneuploid. Which sex chromosome aneuploid is the second most common, and why? Which sex chromosome aneuploid is likely the rarest, and why?arrow_forwardWhat is the relationship between nondisjunction and aneuploidy?arrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage LearningBiology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage Learning