Concept explainers
Neanderthal Hair Color The MCIR gene regulates pigmentation in humans (Sections 14.1 and 15.l revisited), .so loss-of-function mutations in this gene affect hair and .skin color. A person with two mutated alleles for this gene makes more of the reddish melanin than the brownish melanin, resulting in red hair and pa le skin. DNA extracted from two Neanderthal fossils contains a mutated MC1R allele that has not yet been found in humans, To see how the. Neanderthal mutation affects the function of the MC1R gene, Carles Lalueza-Fox and her team introduced the allele into cultured monkey cells (FIGURE 26.1 6).
FIGURE 26.16 MC1R activity in monkey cells transgenic for an unmutated MClR gene, the Neanderthal MC1R allele or the gene for green fluorescent protein (GFP). GFP is- not related to MC1R.
2. What does this imply about the mutation’s effect on Neanderthal hair color?
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- Neanderthal Hair Color The MCIR gene regulates pigmentation in humans (Sections 14.1 and 15.l revisited), .so loss-of-function mutations in this gene affect hair and .skin color. A person with two mutated alleles for this gene makes more of the reddish melanin than the brownish melanin, resulting in red hair and pa le skin. DNA extracted from two Neanderthal fossils contains a mutated MC1R allele that has not yet been found in humans, To see how the. Neanderthal mutation affects the function of the MC1R gene, Carles Lalueza-Fox and her team introduced the allele into cultured monkey cells (FIGURE 26.1 6). FIGURE 26.16 MC1R activity in monkey cells transgenic for an unmutated MClR gene, the Neanderthal MC1R allele or the gene for green fluorescent protein (GFP). GFP is- not related to MC1R. What purpose do the cells with the gene for green fluorescent protein serve in this experiment?arrow_forwardNeanderthal Hair Color The MC1R gene regulates pigmentation in humans (Sections 14.1 and 15.1 revisited), so loss-of-function mutations in this gene affect hair and skin color. A person with two mutated alleles for this gene makes more of the reddish melanin than the brownish melanin, resulting in red hair and pale skin. DNA extracted from two Neanderthal fossils contains a mutated MC1R allele that has not yet been found in humans. To see how the Neanderthal mutation affects the function of the MC1R gene. Carles Lalueza-Fox and her team introduced the allele into cultured monkey cells (FIGURE 26.16). FIGURE 26.16 MC1R activity in monkey cells transgenic for an unmutated MC1R gene, the Neanderthal MC1R allele, or the gene for green fluorescent protein (GFP). GFP is not related to MC1R. 1. How did MCR1 activity in monkey cells with the mutant allele differ from that in cells with the normal allele?arrow_forwardWhat phenotypes do you think a homozygous tra1hsn animal with a loss of function Egl-1 mutation would have.arrow_forward
- Gene Interaction and Epistasis Hair color is due to the presence of melanin. There are two types of melanin produced by melanocytes. One is eumelanin, which is responsible for black (homozygous), brown (heterozygous), and blond (recessive) hair colors. The other is pheomelanin, which is responsible for red hair color. During melanin synthesis, MCR1gene converts pheomelanin to eumelanin. However, a variant of the MCR1 gene (MCR1variant), prevents this conversion. A cross between a blond-haired mother and a red-haired father produced 100% brown-haired children. When they came of age, one child married a double heterozygote, and both were blessed with 7 children; 2 with black hair, 2 with brown hair, 1 with blond hair, and 2 with red hair. Using the 7-step method, determine the genotypes of the P1, the F1, and the F2s. BOX your answers (if handwritten) or HIGHLIGHT your answers (if encoded). STEP 1: ________________________________________________________ STEP 2:…arrow_forwardFigure illustrates albinism in two different species. Describetwo other genetic disorders found in both humans and animals.arrow_forwardThe skin pigment melanin is expressed differently according to exposure to sunlight, with a greater production of the molecule with greater exposure. However, the degree of production can never exceed the inherited genetic level. What evolutionary advantage would be gained from having this phenotypic range for skin pigmentation?arrow_forward
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- Albinism (achromia) is a genetic condition in which an individual cannot synthesize melanin from tyrosine (an amino acid), a brown pigment of the hair, skin, and eyes. These individuals lack whar?arrow_forwardSkin cancer is a disease that occurs when skin cells grow in an uncontrolled way it can be caused by UV light, which can cause alter the genetic sequence of skin cells. which choice below is the best describes how uv light might cause skin cancerarrow_forward1. (a)genes with similar function orthologous genes paralogous genes pseudogenes all of these (b) insulin genes in human and cow orthologous genes paralogous genes pseudogenes all of thesearrow_forward
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