Sex linked traits In humans, as well as with many other animals, sex is determined by special sex chromosomes. An individualcontaining two X chromosomes is a female, while an individual possessing an X and Y chromosome is a male. Thesex chromosomes bear alleles for traits. Sex linkage applies to genes that are located on the sex chromosomes.These genes are considered sex-linked because their expression and inheritance patterns differ between males andfemales. The genes present on the X chromosome are said to be X linked. Many more genes are present on the Xchromosome than found on the Y chromosome. Nonetheless, those genes found on the Y chromosome are said to beY linked. The Y chromosome is smaller than its homologue, the X chromosome. Consequently, most of the locipresent on the X chromosome are absent on the Y chromosome.1. In humans, hemophilia is a sex linked trait. Females can be normal, carriers, or have the disease Males will havethe disease or not (but they won't be ever carriers)XH X= female, normalX" Xh= female, carrierX X= female, hemophilicX Y= male, normalXY= male, hemophilica) Show the cross of a man who has hemophilia with a woman who is a carrierb) What is the probability that their children have the disease NANCEmega-3S00 mgm Fish OilMARTHEALTH2. A woman who is a carrier for hemophilia has children with a normal man. Show the crossa) What is the probability that their children will have hemophilia?b) What sex will a child in the family with hemophilia be?3. A woman who has hemophilia marries a normal man. How many of their children will have hemophilia, andwhat is their sex?4.from the Y chromosome. Normal color vision (XN) is dominant over color blindness (X®). Suppose a color blindman fathers the children of a woman with the genotype XNXN.In humans, color vision is X-linked; the gene for color vision is located on the X chromosome but it is absenta. What genotype is the father?b. What proportion of daughters will be color blind?c. What proportion of sons will be color blind?

Sex linked traits are the traits that are present in the Sex Chromosome that is X and Y . These…

Answered: In humans, as well as with many other…

Human Biology (MindTap Course List)

11th Edition

ISBN:9781305112100

Author:Cecie Starr, Beverly McMillan

Publisher:Cecie Starr, Beverly McMillan

Chapter20: Chromosomes And Human Genetics

Section: Chapter Questions

Problem 2CT: Human sex chromosomes are XX for females and XY for males. a. With respect to an X-linked gene, how...

See similar textbooks

Similar questions

Mutations in DNA that result in altered proteins can causehereditary diseases. Pedigree studies and genetic testing mayclarify the risk of disease. At the chromosome level, nondisjunctionduring meiosis can result in gametes with too few or too manychromosomes, most of which produce inviable offspring.Imprinting refers to inactivation of alleles depending on whichparent the alleles come from; offspring in whom imprinting occursappear haploid for the affected gene even though they are diploid. During spermatogenesis, is there any difference in outcome between first- and second-division nondisjunction?
The gene for the production of eye colour in this species of fruit fly can be expressed aseither normal red-eyes or as brown-eyes. The allele for the normal red eyes is dominant tothat of brown, and is transmitted in normal Mendelian fashion.A gene involved with body colour in this species of fruit fly is located on the non-homologousportion of the X chromosome, and has two alleles, grey and yellow, where the grey allele isdominant to yellow.The two genes are NOT linked.a) Produce a key to clearly show the nature of the alleles associated with the eye colour inthis species of Drosophila, and in each case justify your choice of letters and / or style ofpresentation to best depict the genetics involved.
In humans, as well as in many other animals and some plants, the sex of the individual is determined by sex chromosomes. The sex chromosomes are one pair of non-homologous chromosomes: XX represents a female, while XY represents a male. When a gene for a specific trait Is attached to the X or Y chromosome, we say it is sex-linked, and when it is attached to the X chromosome, we say it is X-linked. Alleles for these linked traits, such as hemophilia or color blindness, crosses, may be recessive or dominant. This is one possible cross (above) for the X-linked condition known as hemophilia. Which pair of parents is most likely to have a hemophiliac daughter? A) carrier mother and unaffected father B) carrier mother and hemophiliac father hemophiliac mother and a carrier father D) unaffected, non-carrier mother and hemophiliac father
Although most tortoiseshell cats are female, a litter of kittens will occasionally contain a male tortoiseshell. Which of the following can explain tortoiseshell coat color in a male kitten? Please explain in detail. The male kitten has an extra Y chromosome The male kitten has an extra X chromosome The male kitten has no X chromosome The male kitten cannot carry out X-inactivation
A family has an X-linked dominant form of congenital generalizedhypertrichosis (excessive hairiness). Although the allele is dominant,males are more severely affected than females. Moreover, the womenin the family often have asymmetrical, hairy patches on their bodies.How does X chromosome inactivation explain this observation?
In mammals, there are two sex chromosomes, X and Y, which behave like homologous chromosomes during meiosis. Normal males have one X chromosome and one Y chromosome, and normal females have two X chromosomes. Males with an extra Y chromosome (XYY) occasionally are found due to inappropriate segregation of the chromosomes (i.e. non-disjunction). Which of the following could give rise to such an XYY male? Answer Yes or No for each situation. nondisjunction in the first meiotic division of spermatogenesis; normal meiosis in the mother nondisjunction in the second meiotic division of spermatogenesis; normal meiosis in the mother nondisjunction in the first meiotic division of oogenesis; normal meiosis in the father nondisjunction in the second meiotic division of oogenesis; normal meiosis in the father
The X chromosome has a lot of traits for things besides the traits we consider female. It carries traits forthings like the ability of your blood to clot correctly and the ability to see differences in the colors red andgreen. If you blood doesn’t clot correctly, it’s called Hemophilia. If you can’t see the difference betweenred and green, you are colorblind. Therefore, these are referred to as X-Linked or Sex-Linked Traits.Notice that those are on the X chromosome only. That means they are missing from the Y. In fact, the Y iscalled Y because it is physically missing a section at the end. This means the Y chromosome is missing genes that the X chromosome has. If you are XY, you only haveone copy of the gene, or one allele. Given what we just said above, can a XY parent pass a X-Linked Trait to his XY offspring?
Males of many diploid species (like us) have X and Y sex chromosomes. They are hemizygous for most X- linked genes. Thus, males express most X-linked alleles, whether they are dominant or recessive in females. In the fruit fly Drosophila, it is common to achieve the equivalent of a test cross of X-linked genes in females by assessing the readily observed phenotypes of their male progeny. Since males do not receive X-linked genes from their father, sires of these crosses can be normal or wild-type flies. In fly genetics, it is conventional to name a gene after the mutant phenotype that enabled its discovery. Your challenge is to establish gene order and map distances between three X-linked genes in Drosophila. Each gene is represented by recessive mutant alleles that express rather distinctive phenotypes relative to their dominant wild-type alternative alleles. Flies expressing fruitless (f) are bisexual, lush (1) have a heightened responses to ethanol, and ken&barbie (kb) lack external…
Human sex chromosomes are XX for females and XY for males. a. With respect to an X-linked gene, how many different types of gametes can a male produce? b. If a female is homozygous for an X-linked allele, how many different types of gametes can she produce with respect to this allele? c. If a female is heterozygous for an X-linked allele, how many different types of gametes can she produce with respect to this allele?
On rare occasions, people are born with a condition known as uniparental disomy. It happens when an individual inherits both copies of achromosome from one parent and no copies from the other parent. Thisoccurs when two abnormal gametes happen to complement each otherto produce a diploid zygote. For example, an abnormal sperm thatlacks chromosome 15 could fertilize an egg that contains two copies ofchromosome 15. In this situation, the individual has maternal uniparental disomy 15 because both copies of chromosome 15 were inheritedfrom the mother. Alternatively, an abnormal sperm with two copies ofchromosome 15 could fertilize an egg with no copies. This is known aspaternal uniparental disomy 15. If a female is born with paternal uniparental disomy 15, would you expect her to be phenotypically normal,have Angelman syndrome (AS), or have Prader-Willi syndrome(PWS)? Explain. Would you expect her to produce normal offspring oroffspring affected with AS or PWS?
In certain salamanders, the sex of a genetic female can be altered, changing her into a functional male; these salamanders are called sexreversed males. When a sex-reversed male is mated with a normal female, approximately 23 of the offspring are female and 13 are male. How is sex determined in these salamanders? Explain the results of this cross.
Which of the following statements is INCORRECT? Synapsis of the X and Y chromosomes in males occurs only at the pseudoautosomal regions. Genes in the pseudoautosomal regions on the Barr body X chromosome escape inactivation. Nonhomologous regions of the X and Y chromosome condense to form a sex vesicle during leptotene. Although one of the two X chromosomes in XXY males becomes a Barr body, XXY males have three doses of the genes in the PAR regions.

SEE MORE QUESTIONS

Recommended textbooks for you

Human Biology (MindTap Course List)

Biology

ISBN:

9781305112100

Author:

Cecie Starr, Beverly McMillan

Publisher:

Cengage Learning

Human Biology (MindTap Course List)

Biology

ISBN:

9781305112100

Author:

Cecie Starr, Beverly McMillan

Publisher:

Cengage Learning

SEE MORE TEXTBOOKS