what is the principle behind the phenomenon of refraction where waves bend when entering a new medium

ATI TEAS 7

TEAS 7 science quizlet

1. What is the principle behind the phenomenon of refraction, where waves bend when entering a new medium?

A. Change in wavelength
B. Change in frequency
C. Change in wave speed
D. None of the above

Correct answer: C

Rationale: Refraction occurs due to a change in wave speed when waves enter a new medium. As waves travel from one medium to another, their speed changes, causing them to bend. This change in speed is responsible for the bending of waves during refraction. It is not the change in wavelength or frequency that causes refraction, but rather the change in speed as waves move through different mediums. Therefore, the correct answer is the change in wave speed (Choice C). Choices A and B are incorrect as refraction is not primarily influenced by changes in wavelength or frequency, but by changes in wave speed. Choice D is also incorrect as there is a specific principle, which is the change in wave speed, behind the phenomenon of refraction.

2. Which of the following is an example of a nosocomial infection?

A. The common cold contracted from a family member
B. A urinary tract infection (UTI) acquired during a catheterization
C. A fungal skin infection from contaminated soil
D. Food poisoning from undercooked chicken

Correct answer: B

Rationale: A nosocomial infection, also known as a healthcare-associated infection (HAI), is an infection that is acquired in a healthcare setting. In this case, a UTI acquired during a catheterization procedure is a classic example of a nosocomial infection. Catheterization involves the insertion of a tube into the urinary tract, which can introduce bacteria into the urinary system and lead to an infection. Nosocomial infections are a significant concern in healthcare settings due to the potential for increased morbidity, mortality, and healthcare costs. Let's review the other options: A) The common cold contracted from a family member - This is not a nosocomial infection as it is acquired outside of a healthcare setting. C) A fungal skin infection from contaminated soil - This is not a nosocomial infection as it is acquired from environmental exposure, not in a healthcare setting.

3. Which of the following is part of the central nervous system?

A. Spinal cord
B. Peripheral nerves
C. Brainstem
D. Cerebellum

Correct answer: A

Rationale: The correct answer is A: Spinal cord. The central nervous system comprises the brain and spinal cord. The spinal cord plays a crucial role in transmitting information between the brain and the body. Choices B, C, and D are not part of the central nervous system. Peripheral nerves belong to the peripheral nervous system, whereas the brainstem and cerebellum are components of the brain, distinct from the central nervous system.

4. Which statement about white blood cells is true?

A. B cells are responsible for antibody production.
B. White blood cells are produced in the bone marrow before entering the bloodstream.
C. Platelets, a specialized class of blood cells, function to clot blood and stop bleeding.
D. The majority of white blood cells are active throughout life, providing immunity across all age groups.

Correct answer: A

Rationale: The correct answer is A: B cells, a type of white blood cell, are responsible for producing antibodies in response to pathogens. Antibodies play a crucial role in identifying and neutralizing foreign substances like bacteria and viruses in the body, aiding in the immune response and protecting against infections. This function is essential for maintaining a healthy immune system. White blood cells, including B cells, are produced in the bone marrow before entering the bloodstream. Platelets, not white blood cells, are a specialized class of blood cells that function to clot blood and stop bleeding. While white blood cells provide immunity, not all of them are active throughout life as some have specific lifespans and functions.

5. Which element is used in fertilizers due to its role in plant cell division and growth?

A. Potassium
B. Phosphorus
C. Calcium
D. Magnesium

Correct answer: B

Rationale: Phosphorus is the correct answer. It is used in fertilizers due to its essential role in plant cell division and growth. Phosphorus is a key component of nucleic acids, such as DNA and RNA, which are essential for cell division and growth in plants. Potassium (Choice A) is important for overall plant health and functions like enzyme activation, but it is not specifically known for its role in cell division and growth. Calcium (Choice C) is crucial for cell wall structure and stability but not primarily for cell division. Magnesium (Choice D) is essential for chlorophyll production and photosynthesis, but it is not directly linked to plant cell division and growth.