Concept explainers
Natural selection changes allele frequencies because some ______ survive and reproduce better than others.
- A. alleles
- B. loci
- C. species
- D. individuals
Introduction:
The term “natural selection” was given and popularized by Charles Darwin. Simply, it is defined as “survival of the fittest”. It is the differential survival of organisms on the basis of their phenotype and genotype. Natural selection is the key to evolution.
Answer to Problem 1TYU
Correct answer:
Some individuals survive and reproduce better than others. Therefore, option (D) is correct.
Explanation of Solution
Reasons for the correct statement:
Some individuals survive and reproduce better than the others. This is due to the difference in genotype or different individuals. Individuals acquire traits, which may be better than the others. This is responsible for natural selection.
Option (D) is given as “individuals”.
“Natural selection changes allele frequencies because some individuals survive and reproduce better than others”, it is the right answer.
Hence, the option (D) is correct.
Reasons for the incorrect statement:
Option (A) is given as “alleles”.
Alleles are defined as alternate form of the same gene. These are found in same loci on the same chromosome. Alleles are a result of mutation. Allele frequency increases as cross-reproduction increases. Same alleles cannot be found in each generation. So, it is a wrong answer.
Option (B) is given as “loci”.
Loci are the fixed location on a chromosome. These define the position of a genetic marker or a gene. These are not responsible for natural selection. So, it is a wrong answer.
Option (C) is given as “species”.
Species is a group of morphologically similar individuals, which are capable of interbreeding. Species evolve due to natural selection, but no two individuals in a species can have the same genotype. Some individuals in a species have better chances of survival than others. So, it is a wrong answer.
Hence, options (A), (B), and (C) are incorrect.
Natural selection is a process of differential selection of individuals. It is the basic reason of evolution. Some individuals in a species have better chances of survival than others and species keep on acquiring new and better traits than previous ones due to this reason.
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