Genetic Drift & Antibiotic Resistance

What is genetic drift?

• the changes in allele frequencies (genes) ,in a population, happening due to random events/circumstances.

• It is an example of primary succession

• Genetic drift are different organisms in a population due to inherited traits from their parents

• It is part of symbiotic relationships such as mutualism, commensalism, parasitism

 Genetic Drift is more likely to happen in... 

• aquatic populations
• small populations
• terrestrial populations
• older populations

A mutation is defined as:

• A change in the cell's structure

• Anything that changes in an embryo

• Any change in the physical features of a human

• A change in the DNA sequence

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.

What characteristic did Darwin observe about the finches on the Galapagos Islands?

• Their feathers

• Genotypes

• Their beaks

• Their body sizes

Hunting reduced the population size of the northern elephant seal to as few as 20 individuals at the end of the 19th century. Their population has since rebounded to over 30,000, but much have less genetic variation than a population of southern elephant seals that were not intensely hunted. How is the lack of genetic variation related to the hunting episodes of the 1800's?

• Genetic Drift Occurred/Genetic Bottleneck: the few individuals left behind were the seals that passed on the specific gene pool.

• Genetic Drift Occurred/Founder Effect: the few individuals left behind were the seals that passed on the specific gene pool.

• Natural Selection Occurred/Survival of the Fittest: only the strongest northern elephant seals survived in the 1800's and that restricted gene pool exists today.

• Adaptation Occurred: Some seals were able to adapt to the hunting environment and they survived to pass on their genes.

Which of the following is a factor in natural selection?

• Individuals of species compete with one another to survive.
• All species are genetically diverse.
• Individuals better able to adapt to changes leave more offspring.
• All are correct 

The small seeded plants in an area were killed by a fungus. Finches with a small beak cannot crack open the large seeds from the plants that were left. What type of selection is likely to occur?

• directional selection

• stabilizing selection

• disruptive selection

• artificial selection

What is antibiotic resistance?

• The ability for humans to resist antibiotics.
• The ability for humans to repel bacteria. 
• The ability for bacteria to resist antibiotics.
• The ability for bacteria to become weak from antibiotics.

People are making antibiotic resistance worse by: (Select all that apply)

• Taking antibiotics only when they need them

• Not finishing the full course of prescribed antibiotics

• Not sharing antibiotics with others

• Taking antibiotics for when they have a virus