Examples of Natural Selection

What is the primary reason for the melting of glaciers in Glacier National Park, as discussed in the video?

• Increased volcanic activity.

• A natural cooling cycle.

• The Earth getting warmer.

• Reduced snowfall in winter.

What is a key outcome of natural selection?

• It creates random events that cause evolution.

• It leads to organisms that are better adapted to their environment.

• It primarily causes mutations in genes.

• It only affects the flowering times of plants.

How did Henry David Thoreau's journal entries contribute to understanding environmental change?

• They provided detailed maps of Walden Pond's ecosystem.

• They documented the specific dates of plant flowering, which can be used to track climate changes.

• They described new species of plants and animals.

• They offered philosophical insights into human interaction with nature.

What type of selection is exemplified by the shift in blueberry flowering times due to a warming climate?

• Stabilizing selection.

• Disruptive selection.

• Artificial selection.

• Directional selection.

What is the fundamental source of novel phenotypic variations in organisms?

• Environmental adaptations

• Changes in DNA sequences

• Behavioral learning

• Dietary modifications

In regions with high malaria prevalence, individuals heterozygous for the sickle cell trait often have a survival advantage. What is the primary reason for this advantage?

• Enhanced oxygen-carrying capacity in red blood cells

• Increased resistance to the malaria parasite

• Improved immune response to bacterial infections

• Reduced susceptibility to other genetic disorders

How does the incomplete course of antibiotic treatment contribute to the development of multi-drug resistant (MDR) bacterial strains?

• It strengthens the bacteria's cell walls, making them impermeable to antibiotics

• It allows the most resistant bacteria to survive and reproduce, passing on their resistance

• It causes the antibiotics to mutate, becoming less effective over time

• It triggers the bacteria to produce enzymes that neutralize the antibiotics

The emergence of multi-drug resistant tuberculosis (MDR-TB) is an example of what phenomenon driven by human actions?

• Genetic engineering

• Artificial selection

• Convergent evolution

• Symbiotic relationships