18.2 Evolution as Genetic Change

Where the better adapted organisms survive to pass traits along to offspring.

• Evolution

• Natural Selection

• Extinction

• Artifical Selection

Answer explanation

Natural selection is the process where better adapted organisms survive and pass traits to offspring, ensuring their survival and evolution.

What process is being shown in this image?

• Variation

• Natural Selection

• Selective Breeding

• Homeostasis

Answer explanation

The process shown in the image is Natural Selection. It is the mechanism by which certain traits become more or less common in a population over time, based on their impact on survival and reproduction.

Genetic drift is change in the allele frequency of a population due to...

• random chance

• natural selection

• non-random mating (sexual selection)

• artificial selection

Answer explanation

Genetic drift is the change in allele frequency of a population due to random chance.

 Genetic Drift is more likely to happen in... 

• aquatic populations

• small populations

• terrestrial populations

• older populations

Answer explanation

Genetic drift is more likely to happen in small populations due to the increased impact of random events on allele frequencies.

This mechanism of evolution occurs when individuals migrate between populations.

• Extinction

• Gene flow

• Genetic drift

• Natural Selection

Answer explanation

Gene flow is the mechanism of evolution that occurs when individuals migrate between populations.

When individuals choose traits possessed by the opposite sex it is called…

• Mutation

• Gene Flow

• Genetic Drift

• Sexual Selection

Answer explanation

When individuals choose traits possessed by the opposite sex, it is called sexual selection. This process involves the selection of certain traits that enhance an individual's chances of mating and reproductive success.

Which of the following is an example of the bottleneck effect?

• Cheetah populations reach their lowest levels with reduced diversity and as they rebound are so genetically similar they appear to be inbred.

• Affected individuals with blue skin can trace their ancestry back to one of the first settlers in the region.

• The environment of a fox population changes and over time foxes who are white survive and pass on their genes to their offspring.

• Humans choose two dogs they like the characteristics of and breed them together.

Answer explanation

The correct choice is when cheetah populations reach their lowest levels with reduced diversity and rebound with genetic similarity, appearing inbred.

Which of the following is an example of the founder effect?

• Humans choose two dogs they like the characteristics of and breed them together.

• Affected individuals with blue skin can trace their ancestry back to one of the first settlers in the region.

• The environment of a fox population changes and over time foxes who are white survive and pass on their genes to their offspring.

• Cheetah populations reach their lowest levels with reduced diversity and as they rebound are so genetically similar they appear to be inbred.

Answer explanation

The founder effect is exemplified by affected individuals with blue skin tracing their ancestry back to one of the first settlers in the region.

determined by dividing the number of a certain allele by the total number of alleles of all types in the population

• population genetics

• microevolution

• gene pool

• allele frequency

Answer explanation

Allele frequency is determined by dividing the number of a certain allele by the total number of alleles in the population. It represents the proportion of a specific allele in a gene pool.

What does the picture represent?

• Founder Effect

• Mutations

• Bottleneck effect

• Gene Flow

Answer explanation

The picture represents the Bottleneck effect, which occurs when a population is drastically reduced in size, leading to a loss of genetic diversity.