TEAS 7 science study guide free

Correct Answer: A

Rationale: The correct answer is A: Phagocytes. Phagocytes are the body's first line of defense against pathogens. They are innate immune cells that engulf and digest foreign particles like bacteria and viruses, preventing infections. Phagocytes act as the initial barrier to invading pathogens and are part of the innate immune response. Choice B, Antibodies, are produced by B cells in the adaptive immune response. Choice C, Memory B cells, are also part of the adaptive immune response and provide a faster and stronger response upon re-exposure to pathogens. Choice D, T lymphocytes, are part of the adaptive immune response, particularly involved in cell-mediated immunity.

Correct Answer: A

Rationale: The Aufbau principle states that electrons fill orbitals in order of increasing energy. This principle helps to explain the electron configuration of atoms and how electrons are distributed within the energy levels and sublevels of an atom. By following the Aufbau principle, one can determine the electron configuration of an atom by sequentially adding electrons to orbitals in order of their increasing energy levels, starting with the lowest energy level. Choice B is incorrect as it describes the Pauli Exclusion Principle, which states that no two electrons in an atom can have the same four quantum numbers. Choice C is incorrect as it refers to the formula for calculating the maximum number of electrons that can occupy an energy level. Choice D is incorrect as it relates to Coulomb's law, which describes the electrostatic interaction between charged particles.

Correct Answer: C

Rationale: The correct answer is C. The kidneys do not produce red blood cells. This function is carried out by the bone marrow. The primary functions of the kidneys include filtering waste products from the blood, regulating blood pressure, and maintaining water balance in the body. Red blood cells are produced in the bone marrow, not in the kidneys. Choices A, B, and D are incorrect as they are primary functions of the kidneys, which involve filtering waste products, regulating blood pressure, and maintaining water balance in the body, respectively.

Correct Answer: C

Rationale: Disinfecting and reusing sterile medical devices is not a recommended method for preventing healthcare-associated infections (HAIs). Reusing sterile medical devices can increase the risk of infections due to inadequate sterilization or potential damage to the devices during the reprocessing process. Proper sterilization and disposal of single-use medical devices are essential in preventing the transmission of infections in healthcare settings. A) Handwashing with soap and water is a crucial method for preventing HAIs as it helps to remove and reduce the number of pathogens on the hands of healthcare workers, preventing the spread of infections. B) Proper use of personal protective equipment (PPE) such as gloves, gowns, masks, and eye protection is important in preventing the transmission of infections between patients and healthcare workers. C) Disinfecting and reusing sterile medical devices is not a recommended practice as it can lead to the transmission of infections if the devices are not adequately sterilized. Using single-use sterile medical devices helps to ensure that each patient receives a sterile device, reducing the risk of infections.

Correct Answer: C

Rationale: Chronic stress can weaken the immune system by increasing the production of stress hormones like cortisol, which can suppress the immune response. This suppression can make individuals more susceptible to infections and illnesses. Conversely, regular exercise, a balanced diet, and adequate sleep actually support a healthy immune system and help strengthen it. Choices A, B, and D are incorrect as they are factors that generally contribute positively to the immune system. Regular exercise, a balanced diet, and adequate sleep are crucial for maintaining overall health and boosting the immune system rather than weakening it.