Nursing Elites

1. When light interacts with a perfectly smooth surface, like a mirror, the dominant interaction is:

• A. Refraction
• B. Diffraction
• C. Total internal reflection
• D. Specular reflection

Correct answer: D

Rationale: The correct answer is D: Specular reflection. When light interacts with a perfectly smooth surface like a mirror, it undergoes specular reflection, where the light rays are reflected at the same angle as the incident angle. Refraction (option A) occurs when light passes from one medium to another at an angle, causing it to change direction. Diffraction (option B) is the bending of light waves around obstacles or through small openings. Total internal reflection (option C) occurs when light traveling in a medium strikes the boundary with another medium at an angle greater than the critical angle, causing the light to reflect back into the original medium. In the case of a perfectly smooth surface, specular reflection is the dominant interaction as the light rays reflect in a single direction with minimal scattering or diffraction.

2. During exercise, heart rate increases to deliver more oxygen to the body's tissues. What other cardiovascular response also increases?

• A. Blood pressure decreases
• B. Blood vessel diameter narrows
• C. Blood flow to muscles increases
• D. Blood viscosity thickens

Correct answer: A

Rationale: The correct answer is A: 'Blood pressure decreases.' When the heart rate increases during exercise to deliver more oxygen to the body's tissues, the blood pressure also tends to decrease. This is due to the enhanced efficiency of the heart in pumping blood, resulting in a lower pressure exerted on the blood vessel walls. In contrast, options B and D are incorrect as blood vessel diameter typically widens (dilates) during exercise to facilitate increased blood flow, and blood viscosity does not usually thicken during exercise. Option C is a distractor as blood flow to muscles indeed increases during exercise to meet the higher demand for oxygen and nutrients.

3. Where does most of the chemical digestion and absorption of nutrients occur?

• A. Mouth
• B. Stomach
• C. Small intestine
• D. Large intestine

Correct answer: C

Rationale: Rationale: The small intestine is where most of the chemical digestion and absorption of nutrients occur in the digestive system. This is because the small intestine is lined with villi and microvilli, which increase the surface area available for absorption. Enzymes secreted by the pancreas and bile from the liver aid in breaking down food into smaller molecules that can be absorbed through the intestinal wall into the bloodstream. The stomach primarily functions in the mechanical breakdown of food and the initial stages of protein digestion, while the large intestine is mainly responsible for absorbing water and electrolytes from the remaining indigestible food particles. The mouth is involved in the initial mechanical breakdown of food through chewing and some chemical digestion of carbohydrates by salivary enzymes, but the majority of nutrient absorption occurs in the small intestine.

4. Adaptive radiation refers to the evolutionary process where:

• A. A single ancestral species diversifies into multiple descendant species due to ecological pressures in a heterogeneous environment.
• B. Two unrelated species evolve similar adaptations in response to similar environments, leading to convergent evolution.
• C. A population becomes increasingly well-adapted to its current environment through continued natural selection.
• D. The fossil record exhibits gaps or missing links in the evolutionary history of a lineage.

Correct answer: A

Rationale: Rationale: - Adaptive radiation is a process where a single ancestral species diversifies into multiple descendant species to exploit different ecological niches within a heterogeneous environment. - This diversification occurs due to the different selective pressures present in various habitats, leading to the evolution of distinct traits and adaptations in different descendant species. - Option A accurately describes the process of adaptive radiation, where the initial species undergoes rapid speciation to occupy different ecological roles and adapt to diverse environmental conditions. - Options B, C, and D do not accurately describe adaptive radiation but refer to other evolutionary processes such as convergent evolution, natural selection, and gaps in the fossil record, respectively.

5. The primary source of energy entering most ecosystems is:

• A. Chemical energy stored in bonds
• B. Thermal energy from the Earth's core
• C. Light energy from the sun
• D. Kinetic energy from wind and water

Correct answer: C

Rationale: Rationale: In most ecosystems, the primary source of energy is sunlight. This energy is captured by plants and other photosynthetic organisms through the process of photosynthesis. These organisms convert light energy into chemical energy stored in the bonds of organic molecules, such as glucose. This stored chemical energy is then passed on to other organisms in the ecosystem through the food chain, making sunlight the fundamental source of energy for most ecosystems. Thermal energy from the Earth's core (option B) is not a primary source of energy for ecosystems, as it is not readily accessible to most organisms. Kinetic energy from wind and water (option D) can play a role in some ecosystems, but it is not the primary source of energy. Chemical energy stored in bonds (option A) is a form of energy that is derived ultimately from the sun through photosynthesis.

6. What is the structure that attaches to each chromosome during mitosis?

• A. Centromere
• B. Telomere
• C. Spindle apparatus
• D. Nucleolus

Correct answer: A

Rationale: Rationale: The centromere is the structure that attaches to each chromosome during mitosis. It is a region of the chromosome where the two sister chromatids are held together and where the spindle fibers attach during cell division. The centromere plays a crucial role in ensuring that each daughter cell receives the correct number of chromosomes during cell division. Telomeres are structures found at the ends of chromosomes that protect them from deterioration and fusion with neighboring chromosomes. The spindle apparatus is a structure made of microtubules that helps separate chromosomes during cell division. The nucleolus is a region within the nucleus where ribosomal RNA synthesis occurs and is not directly involved in chromosome attachment during mitosis.

Similar Questions