Concept explainers
Introduction:
DNA is the genetic material of all organisms except some viruses.
Answer to Problem 1SQ
Correct answer:
Mutation serves as the source for new alleles as they change in the protein structure and gene sequence. Hence, the correct answer is option a.
Explanation of Solution
Reason for correct answer:
Option a. is given as “mutation.”
The mutation is the change in the
Reason for incorrect answer:
Option b. is given as, “natural selection.”
Natural selection is a progressive evolutionary process which is brought about by the alteration in the inheritable characteristics in a group of individuals or populations over generations. This helps in the differential selection of the species and their reproduction based on the ability to adapt. Hence, option b. is incorrect.
Option c. is given as, “Genetic drift”.
Genetic drift is the alteration in the frequency of a gene variant that exists within a population, because of a random sampling of organisms. Hence, option c. is incorrect.
Option d. is given as, “Gene flow”.
Gene flow is the passing of the genetic characters in the form of genes from one generation to another generation within a population. The gene flow is constant in a population but varies among different populations or communities. Hence, option d. is incorrect.
Option e. is given as, “All are original sources of new alleles”.
The mutation is the new sources of alleles as it changes the genetic sequence of the genetic material while other phenomenon does not bring about the formation of new alleles. Hence, option e. is incorrect.
Hence, the options b, c, d and e. are incorrect.
A mutation can lead to the change in the gene sequence, which alters the protein and is the cause responsible for the formation of new alleles. Thus, the correct option is a.
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Chapter 17 Solutions
Biology: Concepts And Applications 9th Biology [jan 01 2014] Starr Cecie; Evers
- If a populations allele and genotype frequencies remain constant from generation to generation, (a) the population is undergoing evolutionary change (b) the population is said to be at genetic equilibrium (c) microevolution has taken place (d) directional selection is occurring, but only for a few generations (e) genetic drift is a significant evolutionary forcearrow_forwardMutation (a) leads to adaptive evolutionary change (b) adds to the genetic variation of a population (c) is the result of genetic drift (d) almost always benefits the organism (e) a and barrow_forwardIf a polymorphism is found at a low frequency globally, but has a high frequency in a particular population, this indicates that: A. natural selection has shaped the distribution of that trait. B. it may have been caused by genetic drift. C. a lack of gene flow affected its distribution. D. All of the above. E. None of the above..arrow_forward
- Which of the following statements about natural selection is a misconception? a.Most species don't produce more offspring than the environment can support b.Natural selection acts on heritable variations in a population c.Natural selection involves differential reproductive success d.Natural selection occurs as a result of competition among individuals in a population e.In natural selection, traits that are favoured depend on current environmental conditionsarrow_forwardgentic drift is A. genetic change in an indivdual's lifetime b genetic change over time c. The change in genetic composition of populations over time d. Evolution that happens on a indvidualarrow_forwardUnlike natural selection, is not related to an individual’s ability to survive and may result in offspring that are less well adapted to survive in a particular environment. (a) genetic drift (b) sexual selection (c) directional selection (d) convergent evolutionarrow_forward
- Natural selection operates on populations over many generations. Which of the following allows natural selection to occur? A. the desire and the advantage of a population to remain constant B. the old age of the individuals which causes them to die C. the abilty for populations to change quickly from one trait to the next D. the unequal ability of individuals to survive and reproducearrow_forwardWith stronger natural selection, was the more beneficial allele lost from these small populations?a) It was lost very frequently, and the strength of natural selection did not make any difference.b) It was never lost.c) It was lost a few times, but not very often, and it was lost less frequently under strong selection.d) It was lost a few times, and it was lost more frequently under strong selection.arrow_forwardEvolution is most accurately described as a change in allele frequencies in over time. (a) an individual (b) a species (c) a population (d) a communityarrow_forward
- 1. ____ occurs when allele frequencies change over generation due to random chance. a. extinction b. gene flow c. natural selection d. mutationarrow_forwardGenetic drift can be defined as Group of answer choices A. accidental changes in DNA structure b.how lazy loci evolve c. random change in allele frequency over time D. differences in fitness between allelesarrow_forwardPeople who are heterozygous for the cystic fibrosis gene are morelikely than others to survive a cholera epidemic. This heterozygoteadvantage seems to explain why homozygotes are maintained in thehuman population, and is an example ofa. disruptive selection.b. balanced polymorphism.c. high mutation rate.d. nonrandom mating.arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning