teas 7 practice test free science - Nurselytic

Correct Answer: A

Rationale: The diaphragm is the primary muscle responsible for inhalation during normal breathing. When it contracts, it flattens, increasing the volume of the thoracic cavity and creating a negative pressure that allows air to flow into the lungs. Intercostal muscles also play a role in expanding the chest cavity during inhalation, but the diaphragm is the main driver of the process. Abdominal muscles are primarily involved in exhalation by pushing the diaphragm upward to expel air from the lungs. Pectoral muscles are involved in movements of the arms and shoulders, not in breathing, making them incorrect choices for this question.

Correct Answer: C

Rationale: Vaccines primarily function by stimulating the immune system to develop immunological memory to a specific pathogen. When a vaccine is administered, it exposes the immune system to a harmless version of a pathogen or a piece of it. This exposure triggers the immune response, leading to the production of antibodies and memory cells specific to that pathogen.
Choice A is incorrect because vaccines do not create a physical barrier; rather, they prepare the immune system to recognize and fight specific pathogens.
Choice B is incorrect as vaccines do trigger an immune response, but the primary goal is to create memory rather than inflammation.
Choice D is incorrect as vaccines do not directly activate phagocytes; instead, they stimulate the immune system to generate a targeted response against a particular pathogen.

Correct Answer: D

Rationale:
A) Live attenuated vaccine: This type of vaccine contains a weakened form of the virus or bacteria that causes the disease. When administered, it stimulates an immune response without causing the disease itself.

B)
Toxoid vaccine:
Toxoid vaccines are made from toxins produced by bacteria that have been inactivated. They stimulate the immune system to produce antibodies against the toxin, providing immunity against the disease.

C) Conjugate vaccine: Conjugate vaccines are made by combining a weak antigen with a strong antigen to enhance the immune response. They are commonly used to protect against bacterial infections.

D) Antibiotic: Antibiotics are medications used to treat bacterial infections by killing or inhibiting the growth of bacteria. They are not a type of vaccine but rather a class of antimicrobial drugs.


Therefore, the correct answer is
D) Antibiotic, as it is not a type of vaccine.

Correct Answer: B

Rationale: Immunosuppressive drugs work by suppressing the immune system's activity, which can increase the risk of infections as the body's ability to fight off pathogens is compromised. While allergies can be a side effect of some medications, the primary concern with immunosuppressive drugs is the increased susceptibility to infections.
Therefore, the correct answer is B, increased susceptibility to infections.
Choice A, 'Increased risk of developing allergies,' is incorrect as the primary risk associated with immunosuppressive drugs is not related to allergies.
Choice C, 'Both A and B,' is incorrect as the main concern is the increased susceptibility to infections rather than developing allergies.
Choice D, 'Neither A nor B,' is incorrect as there is a known risk of increased susceptibility to infections when using immunosuppressive drugs.

Correct Answer: D

Rationale: In CH4 (methane), carbon is bonded to four hydrogen atoms. Hydrogen has an oxidation state of +1. Since the overall charge of CH4 is 0, the oxidation state of carbon must be -4 to balance the charges. Each hydrogen contributes an oxidation state of +1, resulting in a total of +4 from hydrogen atoms.
To achieve a total oxidation state of 0 for the molecule, carbon must have an oxidation state of -4 to offset the contribution from hydrogen.
Therefore, the correct answer is -4.

Choices A, B, and C are incorrect: +1 is the oxidation state of hydrogen, -1 is not the oxidation state of carbon in methane, and +2 is not the correct oxidation state of carbon in CH4.