1. Chyle, a milky white fluid, is transported by lymphatic vessels from the:

A. Lungs
B. Intestines
C. Kidneys
D. Skin

Correct answer: B

Rationale: The correct answer is B: Intestines. Chyle is a milky white fluid that is formed in the small intestine during digestion, mainly from the absorption of dietary fats. It is rich in fats and lymphocytes. Lymphatic vessels in the intestines, called lacteals, absorb the chyle and transport it through the lymphatic system. Chyle eventually enters the bloodstream via the thoracic duct. The lungs are responsible for gas exchange, not the transport of chyle. The kidneys are involved in filtering blood and producing urine. The skin is the body's largest organ responsible for protection, temperature regulation, and sensation, but it is not involved in transporting chyle.

2. The involuntary "fight-or-flight" response is controlled by the:

A. Sympathetic nervous system
B. Parasympathetic nervous system
C. Enteric nervous system
D. Sensory nervous system

Correct answer: A

Rationale: The correct answer is A: Sympathetic nervous system. The "fight-or-flight" response is an automatic physiological reaction triggered by the sympathetic nervous system in response to a perceived threat or stressor. This system prepares the body for action by increasing heart rate, dilating pupils, and redirecting blood flow to muscles. The parasympathetic nervous system, on the other hand, controls the body's "rest-and-digest" response, promoting relaxation and digestion. The enteric nervous system primarily regulates the gastrointestinal system, while the sensory nervous system is responsible for transmitting sensory information to the brain. Therefore, the sympathetic nervous system is specifically responsible for initiating the fight-or-flight response.

3. An element with atomic number 26 and mass number 56 is most likely to be:

A. Iron (Fe)
B. Cobalt (Co)
C. Nickel (Ni)
D. Manganese (Mn)

Correct answer: A

Rationale: Iron (Fe) - Fe-56 has 26 protons and aligns with the given atomic number and mass number.

4. Which property of a substance refers to its ability to be stretched into thin wires without breaking?

A. Conductivity
B. Viscosity
C. Ductility
D. Malleability

Correct answer: c

Rationale: Ductility is the property that describes a substance's ability to be stretched into thin wires without breaking.

5. What is the Doppler effect, and how does it explain the shift in frequency of sound waves perceived by an observer?

A. It only affects light waves, not sound waves.
B. It's the change in wave speed due to medium density.
C. It's the perceived change in frequency due to relative motion.
D. It's the bending of waves due to different mediums.

Correct answer: C

Rationale: The Doppler effect describes how the perceived frequency of a wave changes depending on the relative motion between the source and observer. For example, an approaching siren sounds higher pitched due to compressed wavefronts, while a receding siren sounds lower due to stretched wavefronts.

6. Which type of wave requires a medium to travel through?

A. Electromagnetic waves
B. Mechanical waves
C. Sound waves
D. Both a and c

Correct answer: d

Rationale: Both mechanical waves (such as sound waves) and electromagnetic waves (like light) have different requirements for propagation, but both can travel through a medium.