1. Which neurotransmitter is associated with mood, sleep, and memory?

A. Dopamine
B. Serotonin
C. Acetylcholine
D. Glutamate

Correct answer: B

Rationale: The correct answer is B: Serotonin. Serotonin is a neurotransmitter that plays a crucial role in regulating mood, sleep, and memory. It is known as the 'feel-good' neurotransmitter because it helps to promote feelings of well-being and happiness. Serotonin also contributes to the regulation of sleep patterns and plays a role in memory and learning processes. Dopamine is associated with reward and motivation, acetylcholine with muscle movement and cognitive functions, and glutamate with learning and memory as an excitatory neurotransmitter. Therefore, of the options provided, serotonin is the neurotransmitter most closely linked to mood, sleep, and memory.

2. What happens when an atom loses an electron?

A. It becomes a molecule.
B. It gains a positive charge and becomes an ion.
C. It changes its element identity.
D. Nothing happens, it remains neutral.

Correct answer: B

Rationale: It gains a positive charge and becomes an ion. Losing an electron disrupts the charge balance, leaving the atom with more protons than electrons and a positive charge.

3. Which property of a substance describes its ability to conduct heat or electricity?

A. Mass
B. Density
C. Reactivity
D. Conductivity

Correct answer: d

Rationale: Conductivity refers to a substance's ability to conduct heat or electricity.

4. Which additional information would be MOST relevant to the topic of the passage?

A. A detailed history of the development of specific social media platforms.
B. Studies on the psychological effects of prolonged social media use on teenagers.
C. Statistics on the global economic impact of the social media industry.
D. Technical explanations of the algorithms used by social media platforms.

Correct answer: B

Rationale: Studies on the psychological effects of social media use directly relate to the passage's concerns about mental health impacts, making it the most relevant information.

5. Classifications of human tissues exclude:

A. Epithelial tissue
B. Nervous tissue
C. Adipose tissue (a specialized form of connective tissue)
D. Bony tissue

Correct answer: D

Rationale: The correct answer is D: 'Bony tissue.' Classifications of human tissues typically include four main types: epithelial, connective, muscular, and nervous tissue. Bony tissue, also known as osseous tissue, is a specialized form of connective tissue that forms bones in the skeletal system. While bony tissue is an essential component of the human body, it is not typically categorized separately as a distinct tissue type in general tissue classifications. Therefore, it is the exception from the list provided in the question, making it the correct answer.

6. The stomach produces a strong acid to help break down food. What is the name of this acid?

A. Hydrochloric acid
B. Lactic acid
C. Bile
D. Fatty acid

Correct answer: A

Rationale: The correct answer is A: Hydrochloric acid. The stomach produces hydrochloric acid to help break down food by lowering the pH level in the stomach, creating an acidic environment that aids in the digestion of proteins and other nutrients. Lactic acid is produced in muscles during exercise and is not related to stomach digestion. Bile is produced by the liver and helps in the digestion and absorption of fats in the small intestine. Fatty acids are a type of molecule that is a component of fats, not the acid produced by the stomach for digestion.