how does aids cause a failure in the immune system

ATI TEAS 7

ATI TEAS Science Questions

1. How does AIDS impair the immune system?

A. AIDS targets and destroys Helper T-Cells, preventing the activation of Cytotoxic T-Cells or B-Cells.
B. IgE stimulates mast cells to release excessive histamine.
C. IgE inhibits mast cells from releasing sufficient histamine.
D. Helper T-Cells deceive the body into attacking itself.

Correct answer: A

Rationale: AIDS targets and destroys Helper T-Cells, which play a crucial role in coordinating the immune response. By affecting these cells, AIDS prevents the activation of other important immune cells like Cytotoxic T-Cells or B-Cells. This disruption in the immune system's communication and response mechanisms leads to immune system failure and increased vulnerability to infections. Choices B and C are incorrect because they refer to the role of IgE in allergic reactions, which is not directly related to how AIDS impairs the immune system. Choice D is also incorrect as Helper T-Cells being destroyed in AIDS is not about deceiving the body into attacking itself, but rather the direct impact on immune system function.

2. What type of energy is stored in food?

A. Mechanical energy
B. Kinetic energy
C. Chemical potential energy
D. Thermal energy

Correct answer: C

Rationale: Food stores energy in the form of chemical potential energy. This energy is released during digestion and metabolism to provide the body with the energy it needs to function. It is derived from the bonds within the molecules of food, such as carbohydrates, fats, and proteins. Choice A, mechanical energy, is incorrect as food does not store energy in the form of mechanical energy. Choice B, kinetic energy, is incorrect as kinetic energy is associated with the motion of objects, not stored in food. Choice D, thermal energy, is incorrect as thermal energy relates to heat energy, which is not the primary form of energy stored in food.

3. What does nuclear binding energy represent?

A. Separate an electron from its atom
B. Separate protons and neutrons within a nucleus
C. Cause nuclear fission
D. Induce nuclear fusion

Correct answer: B

Rationale: Nuclear binding energy represents the energy required to hold protons and neutrons together within a nucleus. This energy is needed to overcome the electrostatic repulsion between positively charged protons and keep the nucleus stable. Choices A, C, and D are incorrect. Choice A relates to ionization energy, which is the energy required to remove an electron from an atom. Choices C and D refer to nuclear reactions (fission and fusion), which involve processes different from the concept of nuclear binding energy.

4. Differentiate between genotype and phenotype in the context of gene expression.

A. Genotype refers to the physical manifestation of a trait, while phenotype represents its underlying genetic makeup.
B. Genotype encompasses the spectrum of possible traits encoded by an organism's genes, while phenotype signifies the specific trait observed.
C. Genotype denotes the presence of dominant alleles, while phenotype reflects the influence of recessive alleles.
D. There is no distinction; both terms are interchangeable.

Correct answer: B

Rationale: - Genotype refers to the genetic makeup of an organism, including all the genes and alleles it possesses. - Phenotype, on the other hand, refers to the observable physical characteristics or traits of an organism, which result from the interaction between its genotype and the environment. - While genotype represents the genetic potential or range of traits that an organism can express, phenotype reflects the actual expression of specific traits. - Therefore, option B correctly captures the distinction between genotype and phenotype in the context of gene expression.

5. Which property of a substance remains constant regardless of changes in its shape or size?

A. Mass
B. Weight
C. Volume
D. Density

Correct answer: A

Rationale: The correct answer is 'Mass.' Mass is a measure of the amount of matter in an object and remains constant regardless of changes in its shape or size. Weight, volume, and density can all change depending on the conditions, but mass remains the same. Weight is the force exerted on an object due to gravity, which can change based on the gravitational pull. Volume is the amount of space an object occupies, which can change if the shape or size of the object changes. Density is the mass of a substance per unit volume, which can change if either the mass or volume changes. Therefore, in this scenario, mass is the property that remains constant regardless of changes in shape or size.