Nokea
What unit is used for measuring luminous flux, which indicates the perceived brightness of a light source by the human eye?
- A. Candela
- B. Lumen
- C. Lux
- D. Hertz
Correct Answer: B
Rationale: Lumen is the correct unit for measuring luminous flux, which quantifies the total visible light emitted by a source per unit of time. Candela measures luminous intensity, lux measures illuminance, and Hertz measures frequency. Therefore, in the context of measuring the perceived brightness of a light source by the human eye, luminous flux is quantified in lumens.
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What is the process by which muscles convert chemical energy (ATP) into mechanical energy (movement)?
- A. Photosynthesis
- B. Cellular respiration
- C. Muscle contraction
- D. The sliding filament theory
Correct Answer: C
Rationale: Muscle contraction is the correct answer. It is the process by which muscles convert chemical energy (ATP) into mechanical energy (movement). During muscle contraction, the sliding filament theory explains how actin and myosin filaments slide past each other, causing muscle fibers to shorten and generate force. Photosynthesis (option A) is the process by which plants convert light energy into chemical energy. Cellular respiration (option B) is the process by which cells generate ATP from glucose and oxygen. The sliding filament theory (option D) is a detailed explanation of the molecular events that occur during muscle contraction but is not the overall process of converting energy into movement; it focuses on the mechanism within the process of muscle contraction.
What is the structure that connects the ovary to the uterus in the female reproductive system?
- A. Urethra
- B. Fallopian tube
- C. Vagina
- D. Cervix
Correct Answer: B
Rationale: The fallopian tubes are the structures that connect the ovaries to the uterus in the female reproductive system. These tubes serve as a pathway for the egg to travel from the ovary to the uterus, where fertilization typically occurs. Options (A) Urethra, (C) Vagina, and (D) Cervix are not the structures responsible for connecting the ovary to the uterus, making them incorrect choices for this question.
Which structure allows for the selective passage of materials into and out of the cell?
- A. DNA
- B. Protein
- C. Carbohydrate
- D. Phospholipid bilayer
Correct Answer: D
Rationale: The phospholipid bilayer is a crucial component of the cell membrane, surrounding the cell and regulating the passage of materials into and out of the cell. Its structure enables it to be selectively permeable, controlling which substances can pass through. DNA, proteins, and carbohydrates are essential molecules in the cell but do not directly govern the passage of materials like the phospholipid bilayer does. Therefore, the correct answer is the phospholipid bilayer.
Differentiate between the digestive and respiratory systems.
- A. Mouth
- B. Stomach
- C. Small intestine
- D. Lungs
Correct Answer: D
Rationale: The correct answer is D - Lungs. The mouth, stomach, and small intestine are all components of the digestive system, which is responsible for breaking down food into nutrients that the body can absorb. On the other hand, the lungs are part of the respiratory system, which facilitates the exchange of oxygen and carbon dioxide between the body and the environment through breathing. While the digestive system processes food for energy and nutrients, the respiratory system is primarily focused on the exchange of gases necessary for cellular respiration. Choices A, B, and C are incorrect as they are all organs associated with the digestive system and do not pertain to the respiratory system.
What are the three main types of muscle tissue in the human body?
- A. Smooth, cardiac, and voluntary skeletal
- B. Smooth, skeletal, and involuntary cardiac
- C. Voluntary smooth, cardiac, and skeletal
- D. Striated, non-striated, and epithelial
Correct Answer: A
Rationale: The three main types of muscle tissue in the human body are smooth muscle (involuntary), cardiac muscle (involuntary), and voluntary skeletal muscle. Smooth muscle is found in the walls of hollow organs, cardiac muscle is found in the heart, and skeletal muscle is attached to bones and is under voluntary control. Option A correctly identifies these three main types of muscle tissue in the human body. Choice B is incorrect because it lists skeletal muscle as involuntary, which is not accurate. Choice C is incorrect because it lists voluntary smooth muscle, which does not exist as smooth muscle is involuntary. Choice D is incorrect because it uses terms like striated, non-striated, and epithelial, which are not the main types of muscle tissue but rather descriptions related to muscle characteristics and location.