Evolution chapter 18 homework pt3

Why could clean, sterile environments in modern life result in a rise in some genetic diseases such as Alzheimer's?

• In sterile environments, antibiotics only kill the most harmful microbes.

• Sterile environments are directly correlated with a high sugar diet and diabetes.

• Excessive cleanliness encourages the evolution of bacteria with new diseases.

• An increase in life span results in unmasking antagonistic pleiotropy.

Which statement describes the outcome of a situation if the thrifty genotype hypothesis holds true?

• Hunter–gatherers responded to food shortages by moving to regions with better resources.

• Scientists find no evidence that natural selection has favored genes contributing to diabetes.

• Diabetes increases in a hunter–gatherer population abruptly exposed to a high‑sugar diet.

• Obesity decreases in subsistence farmers given sudden access to an excess of calories.

Select the evidence that refutes the thrifty genotype hypothesis.

• Scientists have not found evidence of natural selection acting on genes that cause metabolic disease.

• Hunter‑gatherer populations experienced fewer periods of famine than subsistence farmers.

• Abrupt switches to high‑sugar and high‑fat diets is causing higher rates of metabolic diseases.

• Hunter‑gatherers experienced more cyclical patterns of feast and famine than subsistence farmers.

Scientists apply their knowledge of evolution to improve vaccines. Instead of delivering a dead virus or its

______

• protein fragments

• sugar molecules

• genetic material

some vaccines induce an immune response by delivering a live virus. Scientists must first weaken the virus using the process of

_______

so that no serious illness results.

• attenuation

• reassortment

• recombination

To produce a live polio vaccine, for instance, researchers force the virus to evolve in the cells of a

_________

species in which it does not naturally replicate.

• plant

• bacterial

• primate

The virus manages to survive, mutating as it slowly replicates. As the virus adapts to these cells, it becomes increasingly

__________

able to infect human cells. However, injected in the human body, it can still elicit a strong immune response.

• better

• less

Scientists are also using their knowledge of evolution to create

__________

vaccine.

• an adaptable HIV

• a universal influenza

• a partial measles

Instead of formulating a new vaccine every season, scientists are trying to develop one that stimulates the production of

_______

that would target all strains of the virus.

• one type of antibody

• a suite of antibodies

Standard vaccine antibodies bind to the tip of the

_________

stalk, which continually mutates.

• hemagglutinin

• glutenin

• hemoglobin