1. Which blood vessels are responsible for carrying oxygenated blood away from the heart to the rest of the body?

A. Veins
B. Arteries
C. Capillaries
D. Venules

Correct answer: B

Rationale: The correct answer is B: Arteries. Arteries are blood vessels that carry oxygenated blood away from the heart to the rest of the body. They have thick and elastic walls to withstand the high pressure generated by the pumping action of the heart. Veins, on the other hand, carry deoxygenated blood back to the heart, while capillaries are tiny blood vessels where the exchange of oxygen and nutrients occurs. Venules are small veins that collect blood from capillaries and transport it to larger veins. Therefore, arteries are specifically designed to transport oxygenated blood away from the heart, making them the correct choice in this question.

2. During a healthy heartbeat, the P wave on an ECG represents

A. The repolarization of the ventricles.
B. The electrical conduction through the AV node.
C. The contraction phase of the ventricles (systole)
D. The depolarization of the atria.

Correct answer: D

Rationale: The correct answer is D: The P wave on an ECG represents the depolarization of the atria. During a healthy heartbeat, the P wave is the first positive deflection seen on the ECG and reflects the initiation of the electrical impulse in the atria, leading to atrial contraction. It is followed by the QRS complex, which represents the depolarization of the ventricles. Options A, B, and C are incorrect because the P wave specifically corresponds to atrial depolarization, not repolarization of the ventricles, electrical conduction through the AV node, or ventricular contraction. Understanding the sequence of electrical events in the heart as represented on an ECG is crucial for interpreting cardiac function and identifying potential abnormalities.

3. Electrons occupy specific energy levels around the nucleus with varying probabilities. The electron cloud model depicts electrons existing in distinct energy levels, not fixed orbits, with probabilities of finding them in specific regions.

A. 2 protons and 6 neutrons
B. 2 filled s orbitals and 6 filled p orbitals
C. 2s orbitals with 2 and 6 electrons, respectively
D. 4 filled electron shells

Correct answer: B

Rationale: 2 filled s orbitals and 6 filled p orbitals. This notation indicates two electrons in the 2s orbital and six electrons in the 2p orbitals.

4. Which property of a wave determines its pitch in sound waves?

A. Amplitude
B. Frequency
C. Wavelength
D. Speed

Correct answer: B

Rationale: The pitch of a sound wave is determined by its frequency. Frequency refers to the number of cycles of a wave that occur in a unit of time, usually measured in hertz (Hz). Higher frequencies correspond to higher pitches, while lower frequencies correspond to lower pitches. Amplitude refers to the height of a wave and is related to the loudness of the sound. Wavelength is the distance between two consecutive points in a wave that are in phase, and speed is the rate at which a wave travels through a medium.

5. Which of the following is NOT a route of transmission for a sexually transmitted infection (STI)?

A. Unprotected sexual contact
B. Sharing contaminated needles
C. Deep kissing
D. Mother to child during childbirth

Correct answer: C

Rationale: Rationale: A) Unprotected sexual contact is a common route of transmission for sexually transmitted infections (STIs) as many STIs are spread through genital, anal, or oral sex without the use of barrier protection such as condoms. B) Sharing contaminated needles can also transmit STIs such as HIV and hepatitis B and C, especially among individuals who inject drugs. C) Deep kissing, while it can transmit certain infections like herpes simplex virus (HSV-1) or cytomegalovirus (CMV), is not a common route of transmission for most STIs. D) Mother to child transmission during childbirth can occur with certain STIs such as HIV, syphilis, and herpes, where the infection can be passed from the mother to the baby during delivery. Therefore, deep kissing (option C) is the correct answer as it is not a typical route of transmission for most STIs.

6. Identify the comprehensive protection for the brain.

A. Skull
B. Meninges (Membranes)
C. Cerebrospinal fluid
D. All of the above

Correct answer: D

Rationale: Rationale: A) The skull provides a hard, protective covering for the brain, shielding it from external trauma and injury. B) The meninges are three layers of membranes (dura mater, arachnoid mater, and pia mater) that surround the brain and spinal cord, providing additional protection and cushioning. C) Cerebrospinal fluid is a clear, colorless fluid that surrounds the brain and spinal cord, acting as a shock absorber and providing nutrients to the central nervous system. Together, the skull, meninges, and cerebrospinal fluid work in conjunction to provide comprehensive protection for the brain, making option D the correct answer.