/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q15.2-3CC Consider what you learned about ... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 15: Q15.2-3CC (page 300)

Consider what you learned about dominant and recessive alleles in Concept 14.1. If a disorder were caused by a dominant X-linked allele, how would the inheritance pattern differ from what we see for recessive X-linked disorders?

Short Answer

Expert verified

In both recessive, dominant X-linked disorders, males express the trait because they possess just one X-chromosome. On the other hand, females can be a carrier or diseased in case of recessive X-linked disease but diseased in dominant X-linked conditions because one dominant allele is enough to cause the disease.

Step by step solution

01

Dominant and recessive alleles

There are two alternative forms of a gene; these are called alleles.Out of the two alleles, one is dominant, and the other is recessive.The allele that determines the trait of an organism is dominant alleles, whereas the other allele which does not have any effect on the trait is recessive alleles.

Any individual who possesses one dominant and one recessive allele is called heterozygous, whereas individuals with either both dominant or recessive alleles are called homozygous.

02

Inheritance of recessive X-linked disease

Recessive X-linked disease is caused by the inheritance of two recessive alleles.In contrast, an individual with one recessive allele is a carrier for the disease.

In this condition, males having recessive alleles will express the trait because they are hemizygous. While females who receive one recessive would be the carrier for the disease, and those who receive both the recessive alleles express the trait. Thus, females have an advantage here due to the presence of two recessive alleles.

03

Inheritance of dominant X-linked disease

Dominant X-linked disease is caused by the inheritance of just one dominant allele.Individuals receiving one dominant allele express the trait. Thus,an individual cannot be a carrier for a dominant X-linked trait.

In this condition, males transmit the dominant allele to the daughter, and, thus, daughters are diseased. At the same time, females with dominant alleles will transmit half of the alleles to sons and half to daughters.

04

Difference between the two inheritance patterns

Males receiving defective alleles in both recessive and dominant X-linked disorder express the trait because they have just one X chromosome, which causes the disorder. As a result, males have more X-linked disorders.

On the other hand, females receiving recessive alleles can be carriers for recessive X-linked disorder but are diseased with just one dominant allele in dominant X-linked conditions.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

The\({\chi ^2}\)value means nothing on its own- it is used to find the probability that, assuming the hypothesis is true, the observed data set could have resulted from random fluctuations. A low probability suggests that the observed data are consistent with the hypothesis, and thus the hypothesis should be rejected, A standard cutoff point used by biologists is a probability of 0.05(5%). If the probability corresponding to the\({\chi ^2}\)value is 0.05or considered statistically significant, the hypothesis (that the genes are unlinked) should be rejected. If the probability is above 0.05, the results are not statistically significant: the observed data are consistent with the hypothesis.

To find the probability, locate your\({\chi ^2}\)value in the\({\chi ^2}\)Distribution table in Appendix F. The 鈥渄egree of freedom鈥� (pdf) of your data set is the number of categories (here,4 phenotypes), minus 1, so df=3.

(a). Determines which values on the df =3 line of the table your calculated\({\chi ^2}\)value lies between.

(b). The column headings for these values show the probability range for your\({\chi ^2}\)number. Based on whether there is non-significant (p\( \le \)0.05) or significant (p>0.05) difference between the observed and expected values, are the data consistent with the hypothesis that the two genes are unlinked and assorting independently, or is there enough evidence to reject this hypothesis?

The gene that is activated on the Philadelphia chromosome codes for an intracellular tyrosine kinase. Review the discussion of cell cycle control in Concept 2.3 and explain how the activation of this gene could contribute to the development of cancer.

A wild-type fruit fly (heterozygous for the gray body color and red eyes) is mated with a black fruit fly with purple eyes. The offspring are wild-type, 721; black purple, 751; gray purple, 49; black red, 45. What is the recombination frequency between these genes for the body color and eye color? Using information for problem 3, what fruit flies (genotypes and phenotypes) would you mate to determine the order of the body color, wing size, and eye color genes on the chromosome?

Butterflies have an X-Y sex determination system that is different from that of flies or humans. Female butterflies may be either XY or X0, while butterflies with two or more X chromosomes are males. This photograph shows a tiger swallowtail gynandromorphy, which is half male (left side) and half female (right side). Given that the first division of the zygote divides the embryo into the future right and left halves of the butterfly, propose a hypothesis that explains how nondisjunction during the first mitosis might have produced this unusual looking butterfly.

Crossing over is thought to be evolutionarily advantageous because it continually shuffles genetic alleles into novel combinations. Until recently, it was thought that the genes on the Y chromosome might degenerate because they lack homologous genes on the X chromosome with which to pair up prior to crossing over. However, when the Y chromosome was sequenced, eight large regions were found to be internally homologous to each other, and quite a few of the 78 genes represent duplicates. (Y chromosome researcher David Page has called it a "hall of mirrors.鈥�). Explain what might be a benefit of these regions.
See all solutions

Recommended explanations on Biology Textbooks

Responding to Change

Read Explanation

Energy Transfers

Read Explanation

Communicable Diseases

Read Explanation

Biological Organisms

Read Explanation

Biological Molecules

Read Explanation

Plant Biology

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.