Genetics and Evolutionary Biology

Sexual selection is a form of natural selection where individuals with certain traits are more successful at obtaining mates, leading to differences in reproductive success.

Genetic drift is the change in allele frequencies due to random chance. Because it involves the random loss of alleles, it typically leads to a decrease in genetic diversity within a population.

The genotype is the specific genetic makeup or the set of alleles an organism carries. This is distinct from the phenotype, which is the observable expression of those genes.

Mutation is the ultimate source of new genetic variation. By creating new alleles, mutations increase the overall genetic diversity within a population.

Genetic variation refers to the diversity in gene frequencies between individuals or populations, which is the raw material for natural selection.

Artificial selection is the process where humans breed plants or animals for specific desirable traits. Natural selection occurs without human intervention based on environmental pressures.

An adaptation is a trait that has evolved through natural selection to help an organism survive and reproduce in its environment.

Both sexual reproduction (which creates new genetic combinations) and mutation (random changes in DNA) are responsible for variation within a species. Sexual reproduction alone is incomplete because it doesn't create truly new alleles, and mutation alone only accounts for some variation. Note: there is a typo in 'mutuation' in option D.

A mutation is a permanent change in an organism's DNA. This is the definition - mutations alter the genetic sequence and can be inherited. Gene therapy is a treatment, recombinant DNA is engineered DNA, and genetic engineering is the process - only mutation refers to the permanent change itself. Note: minor typo in 'organisms' should be 'organism's'.

Asexual reproduction involves a single parent and produces genetically identical offspring (clones), which results in reduced genetic diversity compared to sexual reproduction.

Biodiversity encompasses the variety of life at all levels, including genetic diversity (within species), species diversity (number of species), and ecosystem diversity (variety of habitats).

Gene flow, or the movement of individuals and their alleles between populations through migration, is a primary way that new alleles can be introduced into a population without mutation.

Acquired characteristics, such as physical injuries or modifications during an organism's life, are not encoded in the DNA of the gametes. Therefore, these traits are not passed on to offspring.

Natural selection acts on the variation present within a population. While individuals either survive or die, the change in the frequency of traits over generations occurs at the population level.

Genetic diversity provides a range of traits within a population. When environmental pressures change, this diversity increases the likelihood that some individuals possess beneficial traits that allow them to survive and reproduce.