Nursing Elites

1. What impact would the removal of a keystone species have in an ecosystem?

• A. Lead to a decrease in competition among other species
• B. Cause a slight increase in primary productivity
• C. Have a minimal impact on the overall ecosystem structure
• D. Disrupt the food web and cause cascading effects on other populations

Correct answer: D

Rationale: Keystone species play a crucial role in maintaining the balance and structure of an ecosystem due to their significant influence. If a keystone species is removed, it disrupts the delicate food web dynamics and can trigger cascading effects throughout the ecosystem. The disruption in predator-prey relationships can lead to population declines and even extinctions of other species. Options A, B, and C are incorrect because the removal of a keystone species would not decrease competition among other species, cause a slight increase in primary productivity, or have a minimal impact on the overall ecosystem structure. Instead, it would have a profound impact, disrupting the food web and causing cascading effects on other populations.

2. Which type of muscle is found in the heart?

• A. Smooth muscle
• B. Cardiac muscle
• C. Skeletal muscle
• D. Voluntary muscle

Correct answer: B

Rationale: The correct answer is 'B: Cardiac muscle.' Cardiac muscle is the specific type of muscle found in the heart. Unlike smooth muscle and skeletal muscle, cardiac muscle is involuntary and contracts rhythmically to pump blood throughout the body, making it essential for the heart's function. Smooth muscle (Choice A) is found in the walls of hollow organs and blood vessels, while skeletal muscle (Choice C) is attached to bones and responsible for movement. Voluntary muscle (Choice D) is another term for skeletal muscle, which is under conscious control.

3. What is the cycle of infection?

• A. Reservoir host, means of exit, means of transmission, means of entrance, susceptible host
• B. Entry point, transmission, replication, exit, susceptible host
• C. Susceptible host, replication, transmission, entry, exit
• D. Transmission, replication, entry, exit, susceptible host

Correct answer: A

Rationale: The correct answer is A: 'Reservoir host, means of exit, means of transmission, means of entrance, susceptible host.' This cycle of infection involves the pathogen starting in a reservoir host, exiting through a means, being transmitted to another host, entering the new host through a means, and ultimately infecting the susceptible host. Choices B, C, and D are incorrect because they do not follow the correct sequence of events in the cycle of infection.

4. The Hardy-Weinberg equilibrium describes a population that is:

• A. Undergoing rapid evolution due to strong directional selection.
• B. Not evolving and at genetic equilibrium with stable allele frequencies.
• C. Experiencing a founder effect leading to a reduction in genetic diversity.
• D. Dominated by a single homozygous genotype that eliminates all variation.

Correct answer: B

Rationale: The Hardy-Weinberg equilibrium describes a theoretical population in which allele frequencies remain constant from generation to generation, indicating that the population is not evolving. This equilibrium occurs under specific conditions: no mutation, no gene flow, random mating, a large population size, and no natural selection. In this scenario, all genotypes are in proportion to the allele frequencies, and genetic diversity is maintained. Options A, C, and D do not accurately describe a population in Hardy-Weinberg equilibrium. Option A suggests rapid evolution due to strong directional selection, which would disrupt the equilibrium. Option C mentions a founder effect, which can reduce genetic diversity but is not a characteristic of a population in Hardy-Weinberg equilibrium. Option D describes a population dominated by a single homozygous genotype, which also does not align with the genetic diversity seen in a population at Hardy-Weinberg equilibrium.

5. What is the main component of sweat?

• A. Urea
• B. Glucose
• C. Water
• D. Electrolytes

Correct answer: C

Rationale: - Sweat is primarily composed of water, making up the majority of its content. Water helps regulate body temperature by evaporating from the skin's surface, which cools the body down. - While sweat does contain small amounts of other substances like urea, glucose, and electrolytes, water is the main component that is secreted by sweat glands to help regulate body temperature during physical activity or in response to heat.

Similar Questions