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
Question
Chapter 7, Problem 16QP
Summary Introduction
To determine: The reason which makes calico cats almost invariably female.
Introduction: Females have two X chromosomes due to which they have two copies of all the genes present on that chromosome whereas males carry only one copy of X chromosome due to which they have only one copy of the gene present on that chromosome. All female mammals contain a genetically inactive X chromosome which is known as the Barr body. The expression of gene products by the genes present on the X chromosome is equalized in both males and the females.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Nondisjunction which can affect sex chromosomes as well as autosomal chromosomes as a common cause of genetic disorders. Use the space provided to illustrate the process of nondisjunction with the end result being that one cell exhibits in the monopsony me while other one exhibits trisomy. Hint: a sperm will fertilize the egg and add it’s chromosome in the last step)
Recessive epistasis: In a cross between fruit flies that are both double heterozygous for modifier gene and coat color, in the total offspring of 192, how many fruit flies have gray- coat, white coat, and black coat? A recessive allele blocks the expression of the coat color of fruit flies. Show your answer and solution.
MODIFIED TRUE OR FALSE. In the following items, read each statement carefully. I. In humans and other mammals, biological sex is determined by a pair of sex chromosomes: XX in males and XY in females.II. In the sexual pattern of inheritance, an X-linked pattern will be present and can attached both on the X and Y chromosomes.
a. The first statement (I) is correct and the second statement (II) is wrong
b. The first statement (I) is wrong and the second statement (II) is correct
c. Both statements are correct
d. Both statements are wrong
MODIFIED TRUE OR FALSE. In the following items, read each statement carefully. I. One important event that happens in Meiosis at Prophase 1 is when crossing over between sister chromatids of non-homologous chromosomes takes place.II. This crossing over is the exchange of genetic material that causes variations among individuals.
a. The first statement (I) is correct and the second statement (II) is wrong…
Chapter 7 Solutions
Human Heredity: Principles and Issues (MindTap Course List)
Ch. 7.6 - Prob. 1EGCh. 7.6 - Prob. 2EGCh. 7 - As outlined in this chapter, sex can be defined at...Ch. 7 - As outlined in this chapter, sex can be defined at...Ch. 7 - Prob. 1QPCh. 7 - The Human Reproductive System Discuss and compare...Ch. 7 - Prob. 3QPCh. 7 - A Survey of Human Development from Fertilization...Ch. 7 - Prob. 5QPCh. 7 - Prob. 6QP
Ch. 7 - Prob. 7QPCh. 7 - How Is Sex Determined? The absence of a Y...Ch. 7 - Prob. 9QPCh. 7 - Mutations Can Uncouple Chromosomal Sex from...Ch. 7 - Prob. 11QPCh. 7 - Mutations Can Uncouple chromosomal Sex from...Ch. 7 - Prob. 13QPCh. 7 - Sex-Influenced and Sex-Limited Traits What method...Ch. 7 - Prob. 15QPCh. 7 - Prob. 16QPCh. 7 - Equalizing the Expression of X Chromosome Genes in...Ch. 7 - Equalizing the Expression of X Chromosome Genes in...Ch. 7 - Equalizing the Expression of X Chromosome Genes in...
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
- Equalizing the Expression of X Chromosome Genes in Males and Females Individuals with an XXY genotype are sterile males. If one X is inactivated early in embryogenesis, the genotype of the individual effectively becomes XY. Why will this individual not develop as a normal male?arrow_forwardAnalysis of X-Linked Dominant and Recessive Traits The X and Y chromosomes are structurally and genetically distinct. However, they do pair during meiosis at a small region near the tips of their short arms, indicating that the chromosomes are homologous in this region. If a gene lies in this region, will its pattern of transmission be more like that of a sex-linked gene or an autosomal gene? Why?arrow_forwardAnalysis of X-Linked Dominant and Recessive Traits Suppose a couple, both phenotypically normal, have two children: one unaffected daughter and one son affected with a genetic disorder. The phenotype ratio is 1:1, making it difficult to determine whether the trait is autosomal or X-linked. With your knowledge of genetics, what are the genotypes of the parents and children in the autosomal case? In the X-linked case?arrow_forward
- Analysis of Autosomal Recessive and Dominant Traits The father of 12 children begins to show symptoms of Huntington disease. a. What is the probability that Sam, the mans second-oldest son (II-2), will suffer from the disease if he lives a normal life span? (Sams mother and her ancestors do not have the disease.) b. Can you infer anything about the presence of the disease in Sams paternal grandparents?arrow_forwardEqualizing the Expression of X Chromosome Genes in Males and Females Males have only one X chromosome and therefore only one copy of all genes on the X chromosome. Each gene is directly expressed, thus providing the basis of hemizygosity in males. Females have two X chromosomes, but one is always inactivated. Therefore, females, like males, have only one functional copy of all the genes on the X chromosome. Again, each gene must be directly expressed. Why, then, are females not considered hemizygous, and why are they not afflicted with sex-linked recessive diseases as often as males are?arrow_forwardEqualizing the Expression of X Chromosome Genes in Males and Females How many Barr bodies would the following individuals have? a. normal male b. normal female c. Klinefelter male d. Turner femalearrow_forward
- Analysis of Autosomal Recessive and Dominant Traits In the following pedigree, assume that the father of the proband is homozygous for a rare trait. What pattern of inheritance is consistent with this pedigree? In particular, explain the phenotype of the proband.arrow_forwardVariations in Phenotype Expression A genetic disorder characterized by falling asleep in genetics lectures is known to be 20% penetrant. All 90 students in a genetics class are homozygous for this gene. Theoretically, how many of the 90 students will fall asleep during the next lecture?arrow_forwardHow three-point crosses verify Sturtevant’s map of the Drosophila X chromosome.arrow_forward
- GENETICS In a sexually reproducing diploid organism in which 2n=6, a normal meiocyte in reduction should exhibit a total of 3 bivalents at the metaphase plate. Consider the following organism in the previous statement. if there is no crossing over, the number of possible haploids (gamete) genotypes generated by "chromosome shuffling" during meiosis is _____?arrow_forwardCat fur coat color genetics is interesting. Orange fur is dominant (''B'') to black fur (''b'') and piebald, which is white spotting, is dominant (''S'') to non-white-spotted (''s''). Both of those genes are located on the X chromosome. In addition, in cats, somatic cells exhibit X-inactivation randomly, which explains why there are tortoiseshell cats (when heterozygous, have orange and black spots) as well as calico cats (orange and black but also with white spots). An orange and white spotted male is mated with a tortoiseshell female. State the genotype of the male and the female.arrow_forwardCat fur coat color genetics is interesting. Orange fur is dominant (''B'') to black fur (''b'') and piebald, which is white spotting, is dominant (''S'') to non-white-spotted (''s''). Both of those genes are located on the X chromosome. In addition, in cats, somatic cells exhibit X-inactivation randomly, which explains why there are tortoiseshell cats (when heterozygous, have orange and black spots) as well as calico cats (orange and black but also with white spots). An orange and white spotted male is mated with a tortoiseshell female. Draw a dihybrid Punnet square to show the possible offspring: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 Heredity: Principles and Issues (MindTap Co...
Biology
ISBN:9781305251052
Author:Michael Cummings
Publisher:Cengage Learning
Mitochondrial mutations; Author: Useful Genetics;https://www.youtube.com/watch?v=GvgXe-3RJeU;License: CC-BY