Nursing Elites

1. How many moles of oxygen are required to completely react with 5 moles of propane (C3H8) in the combustion reaction?

• A. 5 moles
• B. 10 moles
• C. 15 moles
• D. 20 moles

Correct answer: b

Rationale: The balanced equation is C3H8 + 5O2 → 3CO2 + 4H2O, indicating a 5:10 ratio between moles of oxygen and moles of propane.

2. A scientific theory is:

• A. A personal belief or hunch about how something works.
• B. A well-substantiated explanation based on evidence and repeated testing.
• C. A single experiment's findings not yet confirmed by others.
• D. A fixed and unchanging dogma beyond questioning.

Correct answer: B

Rationale: Theories in science are constantly evolving and open to revision as new data emerges, unlike personal beliefs or fixed dogmas.

3. Differentiate between genotype and phenotype in the context of gene expression.

• A. Genotype refers to the physical manifestation of a trait, while phenotype represents its underlying genetic makeup.
• B. Genotype encompasses the spectrum of possible traits encoded by an organism's genes, while phenotype signifies the specific trait observed.
• C. Genotype denotes the presence of dominant alleles, while phenotype reflects the influence of recessive alleles.
• D. There is no distinction; both terms are interchangeable.

Correct answer: B

Rationale: Rationale: - Genotype refers to the genetic makeup of an organism, including all the genes and alleles it possesses. - Phenotype, on the other hand, refers to the observable physical characteristics or traits of an organism, which result from the interaction between its genotype and the environment. - While genotype represents the genetic potential or range of traits that an organism can express, phenotype reflects the actual expression of specific traits. - Therefore, option B correctly captures the distinction between genotype and phenotype in the context of gene expression.

4. What is the half-life of a radioactive isotope, and how does it relate to its decay rate?

• A. The time it takes for half of the initial sample to decay.
• B. The time it takes for all the sample to decay.
• C. The rate at which new isotopes are created.
• D. The energy released during decay.

Correct answer: A

Rationale: Half-life tells the time it takes for half of the original radioactive nuclei to decay, offering an indication of the decay rate.

5. The liver plays a vital role in digestion. What is one of the main functions of the liver in the digestive system?

• A. Physical breakdown of food
• B. Production of digestive enzymes
• C. Storage and processing of nutrients
• D. Elimination of waste products

Correct answer: C

Rationale: The correct answer is C: 'Storage and processing of nutrients.' The liver is a crucial organ in the digestive system as it performs various functions such as storing nutrients like glucose, vitamins, and minerals, processing nutrients by converting them into usable forms for the body, and regulating their distribution to different parts of the body. While the physical breakdown of food primarily occurs in the mouth and stomach, and the production of digestive enzymes mainly happens in the pancreas and small intestine, the liver's main role is to manage and store the nutrients obtained from the digested food. Therefore, option C is the correct choice for the main function of the liver in the digestive process.

6. Organisms that break down dead organisms and return nutrients to the environment are called:

• A. Producers
• B. Decomposers
• C. Consumers
• D. Parasites

Correct answer: B

Rationale: Rationale: Decomposers are organisms that break down dead organisms and organic matter, such as bacteria, fungi, and some insects. They play a crucial role in the ecosystem by breaking down complex organic materials into simpler forms, releasing nutrients back into the environment for other organisms to use. Producers (option A) are organisms that produce their own food through photosynthesis, consumers (option C) are organisms that consume other organisms for energy, and parasites (option D) are organisms that live on or in another organism and benefit at the host's expense.

Similar Questions