Human Anatomy & Physiology (11th Edition)
11th Edition
ISBN: 9780134580999
Author: Elaine N. Marieb, Katja N. Hoehn
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Topic Video
Question
The incidence of Down syndrome will be high (nearly 50%) among the offspring of a parent with Down syndrome. Diagram meiosis in the Down syndrome parent to explain why progeny have such a high risk for chromosome 21 aneuploidy. Explain in addition why the incidence of Down syndrome among these children might be less than 50%.
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution
Trending nowThis is a popular solution!
Step by stepSolved in 2 steps with 1 images
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
- An allotetraploid plant has 30 chromosomes in its somatic cells and one of its progenitor species has n = 7. What is the chromosome number in the gametes of the other species? Explain.arrow_forwardThe genes F and G are on the same chromosome in a eukaryote. Using a microscope, you can see that a chiasma occurs between these two loci in 24% of the meioses. A double heterozygote could have genotype FG//fg, where the // represents the pair of homologous chromosomes that contain the F and G loci: one homolog contains F and G alleles and the other contains f and g. You cross this FG//fg individual to an fg//fg individual and examine their offspring. What proportion of the offspring do you expect to be Fg//fg? Group of answer choices 48% 6% None of these 12% 24%arrow_forwardA short-tailed weasel contains a total of 6 chromosomes in its somatic cells. Assuming that crossing over does not occur, what is the probability that a gamete will only contain chromosomes of maternal origin? Selected Answer: a. 1/6 Correct Answer: b. 1/8arrow_forward
- please thoroughly explain why the asnwer is barrow_forwardConsider an individual with the AB/ab genotype, and assume that alleles of the A and B genes areunable to recombine during meiosis. If this individual is crossed with an individual who is homozygousrecessive at both genes (ab/ab), what is the expected phenotype ratio in the offspring?arrow_forwardBecause of non-disjunction in some stocks of Drosophila. melanogaster, about 1 in 65,000 egg cells have two copies of the X chromosome and about 1 in 375 egg cells have no X chromosome. Assuming that meiosis in males is ‘always normal', what is the expected frequency of XXX females and XO males arising from any number of fertilized eggs? Do not be concerned as to whether it is lethal or not.arrow_forward
- Explain why heterozygotes for inversions and translocations have low fertility.arrow_forwardIn a turtle species, a diploid cell in the G1 phase of the cell cycle contains 22 picograms of DNA (picogram is a measure of the total mass of the DNA present). How much DNA is present in a cell of the same species at prophase II of meiosis (prophase of the second meiotic division)?arrow_forwardDraw a diagram of meiosis in a cell where 2n = 6, in a case where there is interchromosomal mixing. Use a clearly labelled colour code (what does each colour represent?) to represent the chromosomes.arrow_forward
- In fruit flies, chromosomal crossing over does not occur in meiosis in males, whereas crossing over does occur in meiosis in females. In fruit flies that are heterozygous at many genes (i.e. many maternal and paternal versions of the genes differ), at what stage would cells no longer be heterozygous for any gene during the process of meiosis? a)After the second meiotic division in males, and after the first meiotic division in females. b)After the second meiotic division in both males and females. c)After the first meiotic division in both males and females. d)After the first meiotic division in males, and after the second meiotic division in females.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
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education
Human Anatomy & Physiology (11th Edition)
Biology
ISBN:9780134580999
Author:Elaine N. Marieb, Katja N. Hoehn
Publisher:PEARSON
Biology 2e
Biology
ISBN:9781947172517
Author:Matthew Douglas, Jung Choi, Mary Ann Clark
Publisher:OpenStax
Anatomy & Physiology
Biology
ISBN:9781259398629
Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter
Publisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)
Biology
ISBN:9780815344322
Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter
Publisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & Physiology
Biology
ISBN:9781260159363
Author:Martin, Terry R., Prentice-craver, Cynthia
Publisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)
Biology
ISBN:9781260231700
Author:Sylvia S. Mader, Michael Windelspecht
Publisher:McGraw Hill Education