Correct Answer: D

Rationale: Adipose tissue serves multiple functions in the body, including insulation to regulate body temperature, energy storage in the form of triglycerides, and hormone production such as leptin and adiponectin. Adipose tissue does not directly participate in muscle movement. Muscle movement is primarily carried out by skeletal muscle tissue, which is responsible for voluntary movements and locomotion. Therefore, the correct answer is D, as adipose tissue is not involved in muscle movement.

Correct Answer: A

Rationale: When the mass of a substance increases while its volume remains constant, the density, which is calculated by dividing mass by volume, will increase. This is because with a higher mass and the volume staying the same, the ratio of mass to volume (density) will be greater, resulting in an overall increase in density. Choice B, 'Density decreases,' is incorrect because an increase in mass with constant volume leads to a higher density. Choice C, 'Density remains constant,' is incorrect as an increase in mass will cause the density to increase. Choice D, 'Density becomes zero,' is incorrect because even with an increase in mass, as long as volume remains constant, density will not reach zero; it will increase instead.

Correct Answer: D

Rationale: Blood type O is considered the universal donor because individuals with type O blood can donate red blood cells to individuals with any ABO blood type (A, B, AB, or O) without causing an adverse reaction. Type O blood lacks A or B antigens on the surface of red blood cells, minimizing the risk of an immune response when transfused into individuals with different blood types. Therefore, type O blood is in high demand for blood transfusions in emergency situations when the recipient's blood type is unknown or when there is a shortage of specific blood types. Choices A, B, and AB are not considered universal donors. Individuals with blood types A, B, or AB can only donate to individuals with compatible blood types to avoid adverse reactions since they have A and/or B antigens on the surface of their red blood cells, making them incompatible with all blood types.

Correct Answer: B

Rationale: The focal length is the term used to describe the point where parallel rays of light converge or appear to diverge after passing through a lens or reflecting off a mirror. It is a fundamental concept in optics that determines the behavior of light rays in optical systems. The focal length directly affects image formation, magnification, and focus. Options (A) Aperture, (C) Refractive index, and (D) Lens thickness are not specifically associated with the convergence or divergence of light rays in optical systems. Aperture refers to the opening through which light passes, refractive index is a measure of how much light bends when entering a medium, and lens thickness is unrelated to the convergence or divergence of light rays.

Correct Answer: C

Rationale: - The atomic number (Z) represents the number of protons in an atom. In this case, the atomic number is 20. - The mass number (A) represents the total number of protons and neutrons in an atom. In this case, the mass number is 40. - To find the number of neutrons, you subtract the atomic number from the mass number: Neutrons = Mass number - Atomic number. - Neutrons = 40 - 20 = 20. - Therefore, the element with atomic number 20 and mass number 40 has 20 neutrons.