1. The fatty sheath that insulates some nerve fibers and speeds up signal transmission is called the:

A. Myelin sheath
B. Dura mater
C. Pia mater
D. Arachnoid mater

Correct answer: A

Rationale: The correct answer is A: Myelin sheath. The myelin sheath is a fatty layer that surrounds and insulates certain nerve fibers. It acts as an electrical insulator, speeding up the transmission of nerve impulses along the axon. This insulation helps to prevent signal loss or interference, allowing for faster and more efficient communication between neurons. The other options, B: Dura mater, C: Pia mater, and D: Arachnoid mater, are all layers of the meninges that protect the brain and spinal cord, but they do not play a role in insulating nerve fibers for signal transmission like the myelin sheath does.

2. 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.

3. What is the unit of measurement for force in the International System of Units (SI)?

A. Newton (N)
B. Kilogram (kg)
C. Joule (J)
D. Meter per second squared (m/sÂ²)

Correct answer: a

Rationale: Force is measured in Newtons (N) in the SI system.

4. Which orbital can hold a maximum of 8 electrons?

A. s orbital
B. p orbital
C. d orbital
D. f orbital

Correct answer: C

Rationale: d orbital - Each d orbital can hold a maximum of 2 electrons, and there are 5 d orbitals, totaling 10 possible electrons.

5. A study finds a link between increased sugar intake and obesity. Does this confirm sugar causes obesity?

A. Yes, the study definitively proves causation.
B. No, correlation does not equal causation, other factors might be involved.
C. We need more research to isolate the specific role of sugar.
D. This only applies to people with genetic predispositions to obesity.

Correct answer: C

Rationale: Correlation suggests a link, but other factors might contribute. Further research is needed to establish the direction and strength of any causal relationship.

6. Eliminate the function NOT attributed to the lymphatic system.

A. Fluid drainage from tissues
B. Immune response via white blood cell production
C. Nutrient transport throughout the body
D. Waste removal through lymph nodes

Correct answer: C

Rationale: Rationale: A) Fluid drainage from tissues: This function is attributed to the lymphatic system. Lymphatic vessels collect excess fluid from tissues and return it to the bloodstream. B) Immune response via white blood cell production: The lymphatic system plays a crucial role in the body's immune response by producing and transporting white blood cells, such as lymphocytes, which help fight infections. C) Nutrient transport throughout the body: Nutrient transport is primarily carried out by the circulatory system (blood vessels), not the lymphatic system. The circulatory system transports nutrients, oxygen, and hormones to cells and removes waste products. D) Waste removal through lymph nodes: The lymphatic system helps remove waste and toxins from the body by filtering lymph through lymph nodes, where harmful substances are trapped and destroyed by immune cells. Therefore, the function NOT attributed to the lymphatic system is C) Nutrient transport throughout the body.