1. Histamine, released during an allergic reaction, causes symptoms like:

A. Fever and fatigue
B. Runny nose and itchiness
C. Muscle aches and joint pain
D. Cough and shortness of breath

Correct answer: B

Rationale: The correct answer is B: 'Runny nose and itchiness.' Histamine is a chemical released by the body during an allergic reaction. It causes various symptoms such as itching, sneezing, runny nose, and watery eyes. These symptoms are commonly associated with allergic reactions like hay fever or hives. Fever and fatigue (option A) are not directly caused by histamine release. Muscle aches and joint pain (option C) are not typical symptoms of histamine release during an allergic reaction. Cough and shortness of breath (option D) are more commonly associated with asthma or respiratory allergies rather than histamine release.

2. In an SN2 reaction, the rate of the reaction is affected by

A. Only the concentration of the nucleophile
B. Only the concentration of the electrophile
C. Neither the concentration of the nucleophile nor the electrophile
D. Both the concentration of the nucleophile and the electrophile

Correct answer: D

Rationale: In an SN2 reaction, the rate of the reaction is affected by both the concentration of the nucleophile and the electrophile. This is because in an SN2 reaction, the nucleophile directly attacks the electrophilic center, leading to the formation of the product. A higher concentration of nucleophile increases the chances of successful collisions with the electrophile, thereby increasing the reaction rate. Similarly, a higher concentration of the electrophile provides more reaction sites for the nucleophile to attack, also increasing the rate of the reaction. Therefore, both the nucleophile and electrophile concentrations play crucial roles in determining the rate of an SN2 reaction.

3. Which factor affects the kinetic energy of an object the most?

A. The object's mass
B. The object's velocity
C. The object's displacement
D. The object's potential energy

Correct answer:

Rationale: Kinetic energy is directly proportional to the square of an object's velocity.

4. Percent Increase/Decrease: A medication dosage is increased by 20%. If the original dosage was 100mg, what is the new dosage?

A. 80mg
B. 100mg
C. 120mg
D. 140mg

Correct answer: C

Rationale: Multiply the original dosage (100mg) by 1 + the percentage increase (20% = 0.2) to get 120mg.

5. Which force opposes the relative motion between surfaces in contact?

A. Tension force
B. Frictional force
C. Gravitational force
D. Magnetic force

Correct answer: b

Rationale: Friction is the force that opposes motion between surfaces in contact.

6. The process by which a single-celled organism divides into two identical daughter cells is called

A. Conjugation
B. Binary fission
C. Endocytosis
D. Mitosis

Correct answer: B

Rationale: Rationale: A) Conjugation is a process in which genetic material is transferred between two bacterial cells through a conjugation tube. It does not involve the division of a single-celled organism into two identical daughter cells. B) Binary fission is the process by which a single-celled organism, such as a bacterium, divides into two identical daughter cells. This is a common method of reproduction in prokaryotic organisms. C) Endocytosis is a cellular process in which cells engulf external materials by wrapping them in a vesicle. It is not a method of cell division. D) Mitosis is a type of cell division that occurs in eukaryotic cells, leading to the production of two daughter cells with identical genetic material. However, the question specifically refers to a single-celled organism, which typically undergoes binary fission for reproduction.