What is the primary function of the mucous membrane lining the muscular tube connecting the mouth to the stomach?
- A. Secretion of digestive enzymes
- B. Absorption of nutrients
- C. Lubrication and protection
- D. Storage of bile
Correct Answer: C
Rationale: The primary function of the mucous membrane lining the muscular tube connecting the mouth to the stomach is to provide lubrication and protection. This mucous membrane serves to protect the esophageal lining from damage caused by the passage of food and liquids. It also aids in facilitating the smooth passage of food from the mouth to the stomach by lubricating it, ensuring easier movement. Choices A, B, and D are incorrect as the mucous membrane does not secrete digestive enzymes, absorb nutrients, or store bile. Its main role is primarily related to lubricating and protecting the lining of the tube.
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A collection of organs working together to perform a specific physiological function is known as a(n):
- A. Tissue
- B. Organ system
- C. Organelle
- D. Organ
Correct Answer: B
Rationale: An organ system is a group of organs that work together to perform specific functions in the body. Each organ within the system has a unique role, but they collaborate to achieve a common physiological function. This collaboration allows the body to carry out complex processes efficiently, demonstrating the interconnectedness and interdependence of different organs within the system.
Choice A, 'Tissue,' refers to a group of cells that work together to perform a specific function, not a collection of organs. Choice C, 'Organelle,' is a subunit within a cell that has a specific function and is not a collection of organs. Choice D, 'Organ,' is a single structure composed of different tissues that performs a specific function, not a collection of organs working together.
Centrioles are structures involved in cell division. What is their specific role?
- A. Forming the nuclear envelope
- B. Replicating DNA
- C. Organizing microtubules during cell division
- D. Protein synthesis
Correct Answer: C
Rationale: Centrioles are involved in organizing microtubules during cell division, specifically in forming the mitotic spindle. The mitotic spindle is crucial for the proper alignment and separation of chromosomes during cell division, ensuring the accurate distribution of genetic material to daughter cells. Choice A, forming the nuclear envelope, is incorrect as centrioles do not have a direct role in this process. Choice B, replicating DNA, is incorrect as centrioles are not involved in DNA replication. Choice D, protein synthesis, is incorrect as centrioles do not play a role in protein synthesis.
What is the protective fluid surrounding the brain and spinal cord called?
- A. Blood
- B. Cerebrospinal fluid
- C. Plasma
- D. Myelin
Correct Answer: B
Rationale: Cerebrospinal fluid is the protective fluid that surrounds the brain and spinal cord. It acts as a cushion to protect these vital organs from injury and provides nutrients to the nervous system. Blood, plasma, and myelin are not the fluids specifically surrounding the brain and spinal cord. Blood is found within blood vessels, plasma is the liquid component of blood, and myelin is a fatty substance that forms a protective sheath around nerve fibers.
How are the frequency and wavelength of a wave related?
- A. Inversely proportional
- B. Directly proportional
- C. No relationship
- D. Dependent on the medium
Correct Answer: A
Rationale: The correct answer is that the frequency and wavelength of a wave are inversely proportional. This relationship is defined by the wave equation: speed = frequency x wavelength. When the frequency of a wave increases, its wavelength decreases, and vice versa. This means that as one quantity increases, the other decreases in a consistent manner, illustrating an inverse relationship between frequency and wavelength. Choice B, 'Directly proportional,' is incorrect because an increase in frequency does not lead to an increase in wavelength; they move in opposite directions. Choice C, 'No relationship,' is incorrect as frequency and wavelength are interconnected as described above. Choice D, 'Dependent on the medium,' is incorrect because the relationship between frequency and wavelength is a fundamental property of waves and is not solely determined by the medium through which the wave propagates.
What are the building blocks of proteins?
- A. Sugars
- B. Fatty acids
- C. Amino acids
- D. Nucleotides
Correct Answer: C
Rationale: Proteins are macromolecules made up of long chains of amino acids. Amino acids are the building blocks of proteins and are linked together through peptide bonds to form polypeptide chains, which then fold into specific three-dimensional structures to carry out various functions in the body. Sugars (choice A) are the building blocks of carbohydrates, fatty acids (choice B) are the building blocks of lipids, and nucleotides (choice D) are the building blocks of nucleic acids like DNA and RNA. Therefore, the correct answer is amino acids (choice C), as they are specifically responsible for protein synthesis.