1. Which of the following vitamins is water-soluble and involved in collagen synthesis and wound healing?
A. Vitamin A
B. Vitamin D
C. Vitamin C Correct
D. Vitamin E
Explanation
Vitamin C is a water-soluble vitamin that plays a crucial role in collagen synthesis, which is essential for wound healing. Collagen is a protein that helps in the formation of connective tissues, skin, tendons, and blood vessels. Vitamin C also acts as an antioxidant and helps in the absorption of iron. Vitamins A, D, and E have different functions and are not primarily involved in collagen synthesis or wound healing.
2. What type of covalent bonds are present between the monomers of an enzyme macromolecule?
A. Phosphodiester bonds
B. Glycosidic bonds
C. Ester bonds
D. Peptide bonds Correct
Explanation
Enzymes are a type of biological macromolecules known as proteins. Proteins are composed of amino acid monomers that are linked together by peptide bonds. These peptide bonds form through a condensation reaction between the amino group of one amino acid and the carboxyl group of another amino acid. The specific covalent bonds present between the monomers of an enzyme macromolecule are peptide bonds. Therefore, the correct answer is D: Peptide bonds.
3. A patient goes to the doctor with a cold and sore throat and asks for antibiotics. The doctor refuses to prescribe antibiotics because the illness is caused by which of the following pathogens?
A. Protist
B. Fungus
C. Virus Correct
D. Bacteria
Explanation
The correct answer is C: Virus. Antibiotics are ineffective against viral infections, such as colds and sore throats caused by viruses. They are only effective against bacterial infections. In this case, the doctor refuses to prescribe antibiotics because the patient's illness is viral, not bacterial. It is important to differentiate between viral and bacterial infections to ensure appropriate treatment and avoid unnecessary use of antibiotics, which can contribute to antibiotic resistance.
4. A researcher writes a grant proposal to repeat an experiment that was recently published by another researcher. Which of the following statements best supports the grant proposal?
A. Funding this grant proposal will allow for the continuation of studying this topic.
B. Repeating the published work will provide independent confirmation of the results. Correct
C. Repeating published work with altered variables will extend the previous findings.
D. Supporting this important research will be beneficial for science in the long term.
Explanation
The best support for the grant proposal is that repeating the published work will provide independent confirmation of the results. This is crucial for scientific research as it strengthens the validity and reliability of the original findings. Independent confirmation is essential for verifying the reproducibility and credibility of the study. Options A, C, and D, though somewhat relevant, do not directly address the primary purpose of repeating the experiment for validation and verification in scientific research.
5. Which of the following molecules are found in substantial quantities in both the cell membrane and DNA?
A. Nitrogenous bases
B. Steroids
C. Phosphate groups Correct
D. Lipids
Explanation
Phosphate groups are crucial components of the DNA backbone, forming the phosphodiester bonds between nucleotides. In DNA, the phosphate group connects the 3' carbon of one nucleotide to the 5' carbon of the next nucleotide. In the cell membrane, phospholipids are the main components, with phosphate groups present in the hydrophilic head of the molecule. This key structural feature allows phospholipids to form the lipid bilayer that comprises the cell membrane. While nitrogenous bases are essential components of DNA, they are not found in substantial quantities in the cell membrane. Steroids are not typically abundant in either the cell membrane or DNA. Lipids, although present in the cell membrane, do not have the same substantial presence in DNA as phosphate groups do.