Genetics and Evolution Quiz

How could a mutation NOT result in a phenotypic change?

• Most mutations are reversible when caught early enough.

• Point mutations may not change the amino acid they code for.

• Phenotype is not a result of the DNA sequencing of an organism.

• Addition or deletion of a base will not shift the DNA reading frame.

What is the major source of new alleles in natural populations?

• mutations in sex cells (gametes)

• mutations in somatic cells

• trait selection by natural selection

• adaptations in individual organisms

Which of the following conclusions can be drawn if a mouse has white fur because of a mutation in its DNA?

• The white mouse increases the diversity of the species.

• The white mouse decreases the diversity of the species.

• The internal organs of the white mouse must not function well as those of other mice.

• The white mouse is more likely to survive than other mice because it is more visible to predators.

When does natural selection occur?

• Individual organisms depend on each other to obtain available resources.

• Variations between individual organisms lead to differential survival chances.

• Habitat and nutrient resources in an area are plentiful over a long period of time.

• The conditions in an ecosystem support a wide range of living organisms.

Which statement is true about the role of mutations in the evolution of species?

• Some mutations are contagious and lethal, which can lead to the extinction of a population.

• If the mutation is beneficial, it will become more prevalent in the population's genes over time.

• Any mutation that occurs may affect the population’s gene pool that is already established.

• Most mutations that occur will spread quickly throughout a population, creating new species.

What effect does crossing-over of chromosomes that results from recombination have on evolution of species?

• It allows for genes to flow between populations, decreasing genetic variability.

• Formation of new chromosomes can lead to genetic drift, reducing evolution of new species.

• It allows for new combinations of alleles to be passed to offspring, increasing genetic variability.

• Genetic combinations and frequency of mutations become increasingly limited.

Natural selection is capable of creating changes in which of the following?

• Characteristics in populations over time

• Genetic makeup of individual organisms

• Amount of competition between individuals

• The adaptations an organism possesses

Many of the plants in a grassland environment are specifically adapted to that habitat. Which of the following is NOT an adaptation that led to this type of natural selection?

• Populations of plants naturally exhibit variation.

• Plants produce more offspring than can survive.

• The available resources do not support all of the plants.

• Related plant species share some genetic material.

Genetic drift states that events unrelated to the natural habitat can cause differences in the survival and reproduction of individuals. What is one effect of genetic drift on evolution?

• It produces only the traits in a population that are best adapted to the environment.

• It can cause an unusual amount of genetic variation within a single population of a species.

• It can cause a population's allele frequencies to become predictable.

• It can cause certain traits in a population to decrease leaving the population vulnerable to conditions in the environment.

Gene flow is one force that can cause evolutionary change. Which example best illustrates gene flow?

• A flock of migrating geese enters the territory of another flock and begins interbreeding.

• A flock of geese becomes isolated on an island, and over time, the population begins to exhibit new characteristics.

• Some individuals in a flock of geese have genes that are more advantageous, and over time, the numbers of these geese increase.

• A flock of mitigating geese loses its way to its wintering grounds, leaving other geese without competition for resources and enabling those geese to produce more offspring.