Human Heredity: Principles and Issues (MindTap Course List)
11th Edition
ISBN: 9781305251052
Author: Michael Cummings
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 6, Problem 19QP
The majority of nondisjunction events leading to Down syndrome are maternal in origin. Based on the duration of meiosis in females, speculate on the possible reasons for females contributing aneuploid gametes more frequently than males do.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Briefly describe nondisjunction in meiosis and identify several potential consequences. In other words, what are the possible outcomes?
Though an individual with abberations such as Robertsonian translocation may be phenotypically normal, they can generate gametes through meiosis that have atypical organizations of chromosomes, resulting in recurrent fetal abnormalities or miscarriages. Why, despite these Robertsonian translocations, are affected cells still able to generate typical gametes through meiosis?
A diploid (2n) trihybrid individual with the genotype EeFfGg can make eight genetically different gametes.
Loci E/e and F/f are on chromosome 1 and locus G/g is on chromosome 2. Explain how a gamete containing the alleles e, f and g may be produced by meiosis. Refer specifically to meiotic events occurring during Prophase I, Metaphase I, Anaphase I and Anaphase II. (NB: remember to refer to the organism above).
Chapter 6 Solutions
Human Heredity: Principles and Issues (MindTap Course List)
Ch. 6 - Genetics in Practice case studies are...Ch. 6 - Genetics in Practice case studies are...Ch. 6 - Analyzing Karyotypes 1. Originally, karyotypic...Ch. 6 - Given the karyotype shown at right, is this a male...Ch. 6 - A colleague e-mails you saying that she has...Ch. 6 - What are the two most commonly used methods of...Ch. 6 - Prob. 5QPCh. 6 - Discuss the following sets of terms: a. trisomy...Ch. 6 - What chromosomal abnormality can result from...Ch. 6 - Tetraploidy may result from: a. lack of...
Ch. 6 - A cytology student believes he has identified an...Ch. 6 - An individual is found to have some tetraploid...Ch. 6 - A spermatogonial cell undergoes mitosis before...Ch. 6 - A teratogen is an agent that produces nongenetic...Ch. 6 - As a physician, you deliver a baby with protruding...Ch. 6 - Variations in Chromosome NumberAneuploidy Describe...Ch. 6 - A woman gives birth to monozygotic twins. One boy...Ch. 6 - Assume that a meiotic-nondisjunction event causes...Ch. 6 - Prob. 17QPCh. 6 - What is the genetic basis and phenotype for each...Ch. 6 - The majority of nondisjunction events leading to...Ch. 6 - Prob. 20QPCh. 6 - If all the nondisjunction events leading to Turner...Ch. 6 - Identify the type of chromosomal aberration...Ch. 6 - Describe the chromosomal alterations and phenotype...Ch. 6 - A geneticist discovers that a girl with Down...Ch. 6 - Albinism is caused by an autosomal recessive...Ch. 6 - Fragile-X syndrome causes the most common form of...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- Which is the type ofgamete produced by aheterozygous individual?What is the genotypicalproportion of these gametes?arrow_forwardWhat can be concluded about the severity of nondisjunction that occurs in meiosis I as opposed to meiosis II?arrow_forwardDraw a simple sketch illustrating how nondisjunction in meiosis can lead to Down syndrome.arrow_forward
- If nondisjunction of the sex chromosomes takes place in meiosis I in the male in Figure , what sexual phenotypes and proportions of offspring will be produced?arrow_forwardBriefly illustrate how nondisjunction in meiosis can result in Down syndrome.arrow_forwardPlease explain the outcomes of nondisjunction in meiosis one versus nondisjunction in meiosis two, in terms of the effect on the gametes. Please give an example of a defect that results from nondisjunction in meiosis.arrow_forward
- Meiosis is characterized by the pairing of homologouschromosomes during prophase I. In many species, an elaboratestructure called the synaptonemal complex forms betweenhomologues. During this pairing, homologues may exchangechromosomal material at sites called chiasmata. In meiosis I, thehomologues separate from each other, reducing the chromosomenumber to the haploid state (thus the reductive division). It isfollowed by a second division without replication, during whichsister chromatids become separated. The result of meiosis I and IIis four haploid cells. If sister chromatids separated at the first division, would meiosis still work?arrow_forwardDescribe the consequences of nondisjunction during meiosisarrow_forwardConsider an individual with genotype P/p; Q/q. Assume no crossing over. What is the total number of possible genotypes of gametes that may be produced by this individual?arrow_forward
- Consider an individual with genotype P/p; Q/q. Assume crossing over can occur. What is the total number of possible genotypes of gametes that may be produced by this individual if one crossing over event occurs per cell undergoing meiosis? 1 2 4 8 16arrow_forwardAre there any factors that can cause an increase in the risk of developing an error in the meiotic division; if so, what are they? The duplication or depletion of a chromosome carries various health risks; what error in the chromosomes would be least harmful and what would be the most harmful for the zygote?arrow_forwardShown below are photomicrographs of Rhoeo tradescantia cells undergoing meiosis. Answer the following question for each of the photomicrographs: Identify the cytogenetic abnormality observed (ex. ring, chain, laggard, bridge). Identify the meiotic stage in which these aberrations are observed (as shown in the photomicrograph). Explain how these aberrations are formed and relate to the possible causal mutation(s). Will this result to sterile and/or fertile gametes? Explain.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning
Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning
Human Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning
Human Heredity: Principles and Issues (MindTap Co...
Biology
ISBN:9781305251052
Author:Michael Cummings
Publisher:Cengage Learning
Human Physiology: From Cells to Systems (MindTap ...
Biology
ISBN:9781285866932
Author:Lauralee Sherwood
Publisher:Cengage Learning
Human Biology (MindTap Course List)
Biology
ISBN:9781305112100
Author:Cecie Starr, Beverly McMillan
Publisher:Cengage Learning
Mitochondrial mutations; Author: Useful Genetics;https://www.youtube.com/watch?v=GvgXe-3RJeU;License: CC-BY