1. Which of the following is NOT typically found in healthy urine?

A. Urea
B. Glucose
C. Creatinine
D. Electrolytes

Correct answer: B

Rationale: Glucose is NOT typically found in healthy urine because the kidneys filter glucose from the blood, and any excess is excreted in the urine. In healthy individuals, the renal threshold for glucose reabsorption is low, so glucose should not be present in significant amounts in urine. On the other hand, urea, creatinine, and electrolytes are all normal components of urine. Urea is a waste product of protein metabolism, creatinine is a waste product of muscle metabolism, and electrolytes like sodium and potassium are essential for various bodily functions and are excreted in urine. Therefore, option B is the correct answer as glucose is not typically found in healthy urine.

2. What type of particle carries no charge and mediates the strong nuclear force between protons and neutrons?

A. Electron
B. Photon
C. Gluon
D. Neutrino

Correct answer: C

Rationale: Gluons are the force carriers of the strong nuclear force, holding protons and neutrons together within the nucleus.

3. In the reaction 4Al + 3O2 â†’ 2Al2O3, what is the mole ratio of aluminum to oxygen?

A. 4:3
B. 2:3
C. 3:2
D. 3:4

Correct answer: a

Rationale: The coefficients in the balanced equation represent the mole ratio, which is 4 moles of Al to 3 moles of O2.

4. Immunoglobulin G (IgG) is the most abundant antibody type, responsible for:

A. Immediate allergic reactions
B. Neutralizing toxins and viruses
C. Activating other immune cells
D. Protecting newborns from infections

Correct answer: B

Rationale: The correct answer is B: 'Neutralizing toxins and viruses.' Immunoglobulin G (IgG) is the most abundant antibody type in the blood and tissues. It plays a crucial role in neutralizing toxins and viruses by binding to them and marking them for destruction by other immune cells. IgG is also involved in opsonization, which enhances phagocytosis of pathogens by immune cells. While IgE is primarily responsible for immediate allergic reactions, IgG's main functions are related to immunity against pathogens rather than allergic responses. Activating other immune cells is typically associated with antibodies like IgM, while protecting newborns from infections is mainly attributed to maternal IgG antibodies passed on during pregnancy. Therefore, option B is the most accurate description of IgG's role in the immune system.

5. What are isotopes?

A. Atoms of the same element with different numbers of protons.
B. Atoms of the same element with different numbers of neutrons.
C. Atoms of different elements with the same number of protons.
D. Atoms of different elements with the same number of electrons.

Correct answer: B

Rationale: Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. This means that isotopes have the same atomic number (Z) but different mass numbers (A). For example, carbon-12 (Â¹Â²C), carbon-13 (Â¹Â³C), and carbon-14 (Â¹â´C) are all isotopes of carbon. They all have six protons in their nuclei, but they have different numbers of neutrons: carbon-12 has six neutrons, carbon-13 has seven neutrons, and carbon-14 has eight neutrons.

6. What is the CRISPR-Cas9 system used for in gene editing?

A. To amplify specific DNA sequences.
B. To cut DNA at specific locations.
C. To deliver genes into cells.
D. To sequence entire genomes.

Correct answer: B

Rationale: Rationale: The CRISPR-Cas9 system is a powerful tool used in gene editing to precisely target and cut DNA at specific locations within the genome. This system consists of a guide RNA that directs the Cas9 enzyme to the desired DNA sequence, where it creates a double-strand break. This break can then be repaired by the cell's natural DNA repair mechanisms, allowing for the introduction of specific genetic modifications. Options A, C, and D do not accurately describe the primary function of the CRISPR-Cas9 system in gene editing.