Certain species of blind fish living in perpetual darkness in the ocean depths have evolved from ancestorsthat could see. Research indicates that the brain centers for vision in these fish is degenerating, whereasthe brain centers controlling other senses are enlarging. What might be the MOST probable reason for theloss of vision in these fish?OA. exposure to mutagens that caused the loss of visionB. progressive selection of genetic variants in the population leading to blindness as anevolutionary adaptationC. infection by cave-dwelling microorganisms that has led to degeneration of the eyesO D. extreme high pressure at the ocean depths causing a deterioration of vision

Answer :- Option (B) is correct - Progressive selection of genetic variants in the population…

Certain species of blind fish living in perpetual darkness in the ocean depths have evolved from ancestors that could see. Research indicates that the brain centers for vision in these fish is degenerating, whereas the brain centers controlling other senses are enlarging. What might be the MOST probable reason for the loss of vision in these fish? A. exposure to mutagens that caused the loss of vision B. progressive selection of genetic variants in the population leading to blindness as an evolutionary adaptation C. infection by cave-dwelling microorganisms that has led to degeneration of the eyes D. extreme high pressure at the ocean depths causing a deterioration of vision

Certain species of blind fish living in perpetual darkness in the ocean depths have evolved from ancestors that could see. Research indicates that the brain centers for vision in these fish is degenerating, whereas the brain centers controlling other senses are enlarging. What might be the MOST probable reason for the loss of vision in these fish? A. exposure to mutagens that caused the loss of vision B. progressive selection of genetic variants in the population leading to blindness as an evolutionary adaptation C. infection by cave-dwelling microorganisms that has led to degeneration of the eyes D. extreme high pressure at the ocean depths causing a deterioration of vision

Biology: The Unity and Diversity of Life (MindTap Course List)

14th Edition

ISBN:9781305073951

Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa Starr

Publisher:Cecie Starr, Ralph Taggart, Christine Evers, Lisa Starr

Chapter26: Human Evolution

Section: Chapter Questions

Problem 2DAA: Neanderthal Hair Color The MCIR gene regulates pigmentation in humans (Sections 14.1 and 15.l...

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About 9 percent of Caucasian males are color-blind andcannot distinguish red-colored from green-coloredobjects.a. Offer one genetic model for color blindness.b. Explain why and how color blindness has reached afrequency of 9 percent in this population
Ancient societies used knowledge that traits are heritable in domesticating animals and developing agricultural crops. What might account for the failure to recognize that the same processes operate in humans?
Neanderthal 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?
Steven Frank and Laurence Hurst argued that a cytoplasmically inherited mutation in humans that has severe effects in males but no effect in females will not be eliminated from a population by natural selection because only females pass on mtDNA (S. A. Frank and L. D. Hurst. 1996. Nature 383:224). Using this argument, explain why males with Leber hereditary optic neuropathy are more severely affected than females.
The reason spontaneous mutations do not have an immediate effect on allele frequencies in a large population is that: a. mutations are random events, and mutations may be eitherbeneficial or harmful. b. mutations usually occur in males and have little effect oneggs. c. many mutations exert their effects after an organism hasstopped reproducing. d. mutations are so rare that mutated alleles are greatlyoutnumbered by nonmutated alleles. e. most mutations do not change the amino acid sequence of aprotein.
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 mutations effect on Neanderthal hair color?
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?
Explain how natural selection might be responsible for the PTC taster polymorphism.Why might some populations have a higher frequency of the taster allele than others?
Background: In class we did a project about m and m’s and there ability to evolve and natural selection. (Yes I know they can’t actually evolve it was just used as a example in class) however I can’t figure out this question. Occasionally a mutant may occur and produce a candy that is misshapen or Pointier or flatter than the rest. Often this proves to be a weakness, but a rare mutation may confer extra M&M durability. Other mutations in M&Ms could occur ( like ones that result in a new color). A mutant un you population represents a new _________. What goes in the blank
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1a-Farmers often use pesticides to kill insects to protect their crops. However, insect populations will often develop resistance to any pesticides that are used on them within a few generations. What is the selective pressure in such a scenario? O a. Pesticide treatment O b. The crops Oc. Pesticide resistance Od. The insects Oe. Mutation 1b-What is/are the element(s) required for a population to change due to natural selection? Select all options that are correct below. a. Variability in a population b. Genetic drift c. Inheritance of traits d. Differential survival e. Evolution
Most new mutations are detrimental, yet rare beneficial mutations canbe adaptive. With regard to the fate of new mutations, discuss whetheryou think it is more important for natural selection to select againstdetrimental alleles or to select in favor of beneficial ones. Which doyou think is more significant in human populations?