Some mutations are hereditary because they are passed down to an offspring from a parent carrying a mutation through the germ line, meaning through an egg or sperm cell carrying the mutation. Mutations can introduce new alleles into a population of organisms and increase the population’s genetic variation.
Q. What might cause an allele to become more common in the gene pool of a population?
Natural selection can cause microevolution (change in allele frequencies), with fitness-increasing alleles becoming more common in the population. Natural selection can act on traits determined by alternative alleles of a single gene, or on polygenic traits (traits determined by many genes).
Table of Contents
- Q. What might cause an allele to become more common in the gene pool of a population?
- Q. What is the relationship between population genes and gene pools?
- Q. Can introduce new alleles into a population’s gene pool?
- Q. Which of the following can introduce new alleles into a population’s gene pool quizlet?
- Q. Is evolution caused by random mutation?
- Q. Is mutation always random?
- Q. Why are DNA mutations so rare?
- Q. Which type of mutation is worse frameshift or substitution?
- Q. Why is frameshift mutation more harmful than point mutation?
Q. What is the relationship between population genes and gene pools?
Populations evolve through genetic change. A population’s gene pool includes all the alleles of all the genes of all the individuals within it. A gene pool for a single gene includes all the alleles of that gene present in all individuals. Analysis of a gene pool can reveal variation which is not visible in phenotypes.
Q. Can introduce new alleles into a population’s gene pool?
Gene pool frequencies do not change as a result of migrations in or out of a population. Gene flow occurs only as a result of migrations. Gene flow can cause new alleles to enter a population’s gene pool.
Q. Which of the following can introduce new alleles into a population’s gene pool quizlet?
Evolution by natural selection proceeds by an accumulation of changes that occur by chance. The ultimate source of new alleles is mutation, random changes in the nucleotide sequences of an organism’s DNA. The ultimate source of new alleles is mutation, random changes in the nucleotide sequences of an organism’s DNA.
Q. Is evolution caused by random mutation?
Mutations are random. The mechanisms of evolution — like natural selection and genetic drift — work with the random variation generated by mutation. Factors in the environment are thought to influence the rate of mutation but are not generally thought to influence the direction of mutation.
Q. Is mutation always random?
Mutations are random. Mutations can be beneficial, neutral, or harmful for the organism, but mutations do not “try” to supply what the organism “needs.” Factors in the environment may influence the rate of mutation but are not generally thought to influence the direction of mutation.
Q. Why are DNA mutations so rare?
Within a population, each individual mutation is extremely rare when it first occurs; often there is just one copy of it in the gene pool of an entire species. Some of these mutations are so harmful that they’re eliminated before their carriers are even born.
Q. Which type of mutation is worse frameshift or substitution?
Insertion or deletion results in a frame-shift that changes the reading of subsequent codons and, therefore, alters the entire amino acid sequence that follows the mutation, insertions and deletions are usually more harmful than a substitution in which only a single amino acid is altered.
Q. Why is frameshift mutation more harmful than point mutation?
Nucleotides make up DNA. Therefore, mutations change the order and/or the number of nucleotides changes within DNA. Thus, frameshift mutations may alter all of the codons that occur after the deletion or insertion. Therefore, frameshift mutations tend to be more detrimental than point mutations.
