1. A study finds a specific gene linked to increased risk of heart disease. Does this mean everyone with that gene will develop heart disease?

A. Yes, the gene deterministically causes heart disease.
B. No, other factors also influence heart disease risk.
C. We need more research to clarify the gene's exact role.
D. Only people with a family history of heart disease need to worry.

Correct answer: B

Rationale: The presence of a specific gene linked to an increased risk of heart disease does not guarantee that everyone with that gene will develop the condition. Other factors such as lifestyle, environment, and overall health also play a significant role in determining an individual's risk of heart disease. Therefore, it is essential to consider these additional factors rather than solely attributing the risk to the gene itself.

2. What is the principle behind optical fibers used in communication?

A. Reflection of light within the fiber
B. Refraction of light due to different densities within the fiber
C. Total internal reflection guiding light through the fiber core
D. Diffraction of light around bends in the fiber

Correct answer: C

Rationale: Optical fibers used in communication rely on the principle of total internal reflection guiding light through the fiber core. When light enters the fiber at a certain angle, it reflects off the boundary between the core and cladding, ensuring that the light remains trapped within the core and travels along the fiber without significant loss of signal. This total internal reflection allows for efficient transmission of light signals over long distances in optical communication systems.

3. When does work on an object occur?

A. Only when the object's velocity changes
B. Only when a force is applied to the object
C. Whenever there is a force exerted on the object causing displacement
D. Only when the object is lifted vertically

Correct answer: c

Rationale: Work is done when a force is applied to an object, causing it to move in the direction of the force.

4. Fingernails and toenails are made primarily of:

A. Collagen (Collagen is found in the dermis)
B. Keratin
C. Melanin (Melanin provides pigment, not structure)
D. Sebum (Sebum is an oily substance)

Correct answer: B

Rationale: The correct answer is B: Keratin. Fingernails and toenails are primarily made of a tough protein called keratin. Keratin is a fibrous structural protein that also makes up hair and the outer layer of skin. Collagen, as mentioned in option A, is found in the dermis of the skin and is responsible for providing strength and elasticity to the skin. Melanin, as in option C, is a pigment that gives color to the skin, hair, and eyes, but it does not contribute to the structure of nails. Sebum, as in option D, is an oily substance produced by the sebaceous glands in the skin to moisturize and protect the skin, but it is not a component of nails.

5. Adipose tissue, commonly known as fat, primarily functions in:

A. Support
B. Insulation
C. Energy storage
D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' Adipose tissue, or fat, serves multiple functions in the body. It provides support by cushioning and protecting organs, acts as an insulation layer to maintain body temperature, and serves as a crucial energy storage site where excess energy is stored in the form of triglycerides. Therefore, all of the options listed (support, insulation, and energy storage) are accurate functions of adipose tissue.