In humans, at least one gene produces melanin skin pigment in response to UV radiation (that is, pigment production increases in response to sun exposure, leading to tanning). Thus, a human may have dark skin if they have been exposed to lots of sunlight but may have light skin if they have not been exposed to sunlight. What kind of inherítance is this an example of? Pleiotropy Polygenic inheritance Epistasis Gene-environment interaction

In humans, at least one gene produces melanin skin pigment in response to UV radiation (that is, pigment production increases in response to sun exposure, leading to tanning). Thus, a human may have dark skin if they have been exposed to lots of sunlight but may have light skin if they have not been exposed to sunlight. What kind of inherítance is this an example of? Pleiotropy Polygenic inheritance Epistasis Gene-environment interaction

Human Biology (MindTap Course List)

11th Edition

ISBN:9781305112100

Author:Cecie Starr, Beverly McMillan

Publisher:Cecie Starr, Beverly McMillan

Chapter19: Introduction To Genetics

Section: Chapter Questions

Problem 9CT

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Similar questions

Suppose a maternal effect gene exists as a functional dominantallele and a nonfunctional recessive allele that causes a disorder.A mother with the disorder produces offspring that are all withoutthe disorder. Explain the genotype of the mother.
The maternal-effect mutation bicoid (bcd) is recessive. Inthe absence of the bicoid protein product, embryogenesis isnot completed. Consider a cross between a female heterozygousfor the bicoid mutation (bcd+/ bcd-) and a homozygousmale(bcd-/ bcd-). How is it possible for a male homozygous for the mutationto exist?
Genetic Inheritance Patterms Retinitis pigmnentosa (RP) can be autosomal recessive, autosomal dominant, or x-linked. Apparently the dominant forms are often less severe. Eric's form of RP is Usher's Syndrome, which is an autosomal recessive inheritance (i.e., you must get a copy of the defective gene from your Mom and one from your Dad). Autosomal means it is not carried on one of the chromosomes that determines sex. Usher's Type II is recessive, so for Eric this means that both his Mom and Dad are carriers of this condition. His brother, Dirk, does not have any symptoms of RP. Question below - short answer approach Imagine you are a genetics counselor, and Dirk, Erik's brother, comes in to see you. Based on his parents, what are Dirk's possible genotypes for RP? What advice would you give Dirk about the chances of Dirk's children having retinitis pigmentosa if his wife is not a carrier? How would your advice change if his wife fully has the disease? Describe all the possibilities,…
Suppose a maternal effect gene exists as a functional dominantallele and a nonfunctional recessive allele. A mother who is phenotypically abnormal produces all normal offspring. Explain thegenotype of the mother
Bloom syndrome is an autosomal recessive disease that exhibitshaploinsufficiency. A recent survey showed that people heterozygousfor mutations at the BLM locus are at increased risk of colon cancer.Suppose you are a genetic counselor. A young woman is referred to youwhose mother has Bloom syndrome; the young woman’s father has nofamily history of Bloom syndrome. The young woman asks whether sheis likely to experience any other health problems associated with herfamily history of Bloom syndrome. What advice would you give her?
The maternal-effect mutation bicoid (bcd) is recessive. Inthe absence of the bicoid protein product, embryogenesis isnot completed. Consider a cross between a female heterozygousfor the bicoid mutation (bcd+/ bcd-) and a homozygousmale(bcd-/ bcd-). Predict the outcome (normal vs. failed embryogenesis) inthe F1 and F2 generations of the cross described.
In individuals affected by cystic fibrosis, salt crystals may appear afterperspiration dries up. In addition, the disease causes respiratory disorderswhich can be both debilitating and lethal. It occurs in individuals homozygousfor recessive gene. If 2 normal parents had a daughter with the symptoms ofthis disease, and a normal son, what is the probability that he might be acarrier of the recessive gene?Express answer in fraction form.
Mic2 is a gene present on both the X and Y chromosome of humans. Suppose a mutant form, mic2, results in an abnormal surface antigen. Assume that it is possible to identify heterozygous and homozygous individuals. If you had a large enough pedigree, could one differentiate between autosomal and pseudoautosomal inheritance? Explain.
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When examining a human pedigree, what features do you look forto distinguish between X-linked recessive inheritance and autosomal recessive inheritance? How would you distinguish X-linkeddominant inheritance from autosomal dominant inheritance in ahuman pedigree?
X-linked Recessive Inheritance A gene is described as X-linked when it occurs on the X chromosome and not the Y. Our convention is to indicate X-linkage by attaching the appropriate gene symbol as a superscript on the letter X. Commonly, the wild-type (+) allele is indicated with only a "+" to avoid having to type a superscript on a superscript. For example, a female that is heterozygous and carrying a recessive mutant allele is indicated as X+Xm. Note the convenience of the shorthand + for m+ in this situation. A mutant male has the genotype XmY. When working with X-linked inheritance, always include the X and Y chromosomes in the descriptions of genotypes, and include the sex (male or female) in the descriptions of the phenotypes (e.g., mutant male, wild-type female, etc.). Here are the genotypes and associated phenotypes for X-linked recessive inheritance: X+X+ Wild-type female X+Xm Wild-type female xmxm Mutant female X+Y xmy Wild-type male Mutant male