1. The hormone responsible for milk production in the breasts after childbirth is:

A. Estrogen
B. Prolactin
C. Oxytocin
D. Relaxin

Correct answer: B

Rationale: The correct answer is B: Prolactin. Prolactin is the hormone responsible for milk production in the breasts after childbirth. It is produced by the pituitary gland and stimulates the alveoli in the breasts to produce milk. Estrogen plays a role in breast development during pregnancy but is not responsible for milk production. Oxytocin is responsible for the ejection of milk from the breasts during breastfeeding. Relaxin is a hormone that helps prepare the body for childbirth by relaxing the ligaments in the pelvis. Therefore, the hormone directly responsible for milk production after childbirth is prolactin.

2. Which of the following is an example of aseptic technique?

A. Washing hands with soap and water before surgery
B. Coughing into your elbow
C. Sharing a stethoscope without cleaning
D. Leaving a wound dressing exposed

Correct answer: A

Rationale: Rationale: Aseptic technique refers to practices that help prevent the introduction of harmful microorganisms into a sterile environment. Washing hands with soap and water before surgery is an essential component of aseptic technique as it helps reduce the number of microorganisms on the hands, decreasing the risk of introducing pathogens into the surgical site. Coughing into your elbow is a good hygiene practice to prevent the spread of respiratory infections but is not specifically related to aseptic technique. Sharing a stethoscope without cleaning can introduce microorganisms from one patient to another, compromising aseptic conditions. Leaving a wound dressing exposed can lead to contamination and infection, which is contrary to aseptic technique.

3. Laser light differs from typical light sources due to its properties of:

A. Enhanced brightness only
B. Monochromatic nature (single color) and coherence (synchronized waves)
C. Increased velocity
D. Limited visibility to the human eye

Correct answer: B

Rationale: The correct answer is B: Monochromatic nature (single color) and coherence (synchronized waves). Laser light is unique because it consists of a single color (monochromatic) and its waves are synchronized (coherent), unlike typical light sources which emit a range of colors and incoherent waves. This coherence allows laser light to stay focused over long distances, making it useful in various applications such as surgery, communication, and manufacturing. Enhanced brightness (A) is not the only distinguishing factor of laser light, as coherence and monochromatic nature are equally important. Increased velocity (C) and limited visibility to the human eye (D) are not properties that define laser light. Therefore, option B is the most accurate choice.

4. Which of the following describes a scalar quantity?

A. Velocity
B. Acceleration
C. Force
D. Speed

Correct answer: d

Rationale: Speed is a scalar quantity as it only indicates how fast an object is moving without any directional information.

5. Which mineral is crucial for bone strength and is stored in bones and teeth?

A. Calcium
B. Iron
C. Magnesium
D. Potassium

Correct answer: A

Rationale: The correct answer is A: Calcium. Calcium is crucial for bone strength as it is a key mineral stored in bones and teeth. It plays a vital role in maintaining bone density and strength, helping to prevent conditions like osteoporosis. Without an adequate intake of calcium, individuals may be at risk of developing weak and brittle bones. Iron (B), Magnesium (C), and Potassium (D) are important minerals for various bodily functions, but they are not primarily responsible for bone strength and storage in bones and teeth.

6. A baseball is thrown into the air. At the peak of its trajectory, which of the following forces is acting on the ball?

A. Only gravitational force
B. Only the force of air resistance
C. Both gravitational force and the force of air resistance
D. Neither gravitational force nor the force of air resistance

Correct answer: A

Rationale: At the peak, the ball momentarily stops moving upwards. Its inertia keeps it moving horizontally, but there is no force propelling it upwards except for gravity pulling it down.