Nursing Elites

1. What is represented by this formula: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂?

• A. Glycolysis
• B. Cellular respiration
• C. Photosynthesis
• D. Electronic transport

Correct answer: C

Rationale: The formula represents the process of photosynthesis, where carbon dioxide (CO₂) and water (H₂O) are converted into glucose (C₆H₁₂O₆) and oxygen (O₂) using light energy. This process is essential for plants and some microorganisms to produce food and oxygen. Glycolysis and cellular respiration involve breaking down glucose to produce energy, and the electron transport chain is part of cellular respiration, not photosynthesis.

2. Why are bacteria and blue-green algae often classified together?

• A. Both are gymnosperms.
• B. Both are prokaryotes.
• C. Both are autotrophs.
• D. Both are pathogens.

Correct answer: B

Rationale: Bacteria and blue-green algae (cyanobacteria) are often classified together because they are both prokaryotes. Prokaryotes are unicellular organisms that lack a membrane-bound nucleus and other membrane-bound organelles. This characteristic distinguishes them from eukaryotic organisms, which have these membrane-bound structures. Choice A is incorrect because gymnosperms are seed-producing plants with naked seeds, not bacteria or blue-green algae. Choice C is incorrect because being an autotroph (able to produce its own food) is not a reason for classifying them together. Choice D is incorrect because not all bacteria and blue-green algae are pathogens; many of them are beneficial or neutral to other organisms.

3. Select the option that best shows complementary base pairing in DNA:

• A. A and G
• B. A and C
• C. A and A
• D. A and T

Correct answer: D

Rationale: The correct answer is D. A purine (A) must pair with a pyrimidine (T) in DNA. This eliminates options A and C as they do not follow the rule of complementary base pairing. Adenine (A) always pairs with thymine (T) due to their specific shape and bonding properties in DNA structure. Choice B is incorrect because adenine does not pair with cytosine in DNA.

4. Duchenne muscular dystrophy is a recessive sex-linked trait carried on the X chromosome. In an example of an unaffected father and a female carrier who have two daughters and two sons, which is the predicted outcome?

• A. Both daughters will carry the disease.
• B. Both sons will carry the disease.
• C. One daughter may have the disease.
• D. One son may have the disease.

Correct answer: C

Rationale: Duchenne muscular dystrophy is a recessive sex-linked trait carried on the X chromosome. Since the father is unaffected and does not carry the disease, he must have a normal X chromosome. The mother is a carrier, which means she has one normal X chromosome and one X chromosome with the disease allele. The daughters will inherit one X chromosome from each parent; one would be normal, and the other has a chance of carrying the disease allele. So, there is a 50% chance that one daughter may have the disease, as she could inherit the X chromosome with the disease allele. The sons will inherit the Y chromosome from the father and the X chromosome from the mother, so they will not be affected by the disease. Therefore, the predicted outcome is that one daughter may have the disease, while the sons will not carry the disease. This rules out choices A, B, and D.

5. What are plasma membranes mostly made of?

• A. Proteins
• B. Carbohydrates
• C. Lipids
• D. Nucleotides

Correct answer: C

Rationale: The correct answer is C: Lipids. Plasma membranes are primarily composed of lipids, specifically phospholipids, which form a lipid bilayer. While proteins are also an essential component of plasma membranes, they are not the primary constituent. Carbohydrates are present on the outer surface of the membrane but are not the main structural component. Nucleotides are the building blocks of nucleic acids like DNA and RNA and are not the main constituents of plasma membranes.

Similar Questions