Nokea
Which of the following scenarios represents an example of static friction?
- A. Sliding a heavy box across the floor
- B. A car moving around a curve
- C. Pushing a stationary object
- D. Braking a car to stop
Correct Answer: C
Rationale: The correct answer is C. Static friction occurs when two surfaces are in contact but not moving relative to each other. Pushing a stationary object involves static friction as you apply a force to overcome the friction keeping the object stationary. Choices A, B, and D involve kinetic friction, which occurs when two surfaces are moving relative to each other. Option A involves moving the box across the floor, which is an example of kinetic friction. Option B involves the movement of a car around a curve, which also relates to kinetic friction due to the relative movement between the tires and the road. Option D describes braking a car to stop, where the moving car's wheels interact with the road, creating kinetic friction to slow down and stop the car.
You may also like to solve these questions
Which macromolecule serves as the repository of genetic information in all living organisms?
- A. Ribonucleic acid (RNA)
- B. Deoxyribonucleic acid (DNA)
- C. Protein
- D. Carbohydrate
Correct Answer: B
Rationale: - DNA is the macromolecule that serves as the repository of genetic information in all living organisms. It carries the genetic instructions necessary for the growth, development, functioning, and reproduction of organisms.
- RNA (option A) is involved in various cellular processes, including protein synthesis, but DNA is the primary molecule responsible for storing genetic information.
- Proteins (option C) are essential for various cellular functions but do not serve as the primary repository of genetic information.
- Carbohydrates (option D) are important for energy storage and structural support but do not store genetic information.
Which type of muscle tissue contracts involuntarily and is found in organs like the heart and intestines?
- A. Skeletal muscle
- B. Cardiac muscle
- C. Smooth muscle
- D. All of the above
Correct Answer: C
Rationale: Smooth muscle is the type of muscle tissue that contracts involuntarily and is found in organs like the heart and intestines. Skeletal muscle is responsible for voluntary movements, like those involved in skeletal system actions. Cardiac muscle is found in the heart and contracts involuntarily, but it is distinct from smooth muscle. The heart's muscle is specialized and forms the myocardium, which is not the same as the smooth muscle found in organs like the intestines. Therefore, the correct answer is C) Smooth muscle.
What is the function of the pericardium, the sac surrounding the heart?
- A. To generate electrical impulses for heart contraction
- B. To transport blood throughout the body
- C. To provide lubrication for heart movement
- D. To protect the heart and anchor it in place
Correct Answer: C
Rationale: The pericardium is a double-walled sac that surrounds the heart and contains a small amount of fluid to provide lubrication for the movement of the heart within the chest cavity. It helps reduce friction as the heart beats and moves. Choice A is incorrect because the generation of electrical impulses for heart contraction is primarily the function of the heart's specialized conduction system. Choice B is incorrect as the pericardium is not involved in the transportation of blood throughout the body. Choice D is also incorrect as while the pericardium does protect the heart, its primary function is to provide lubrication and reduce friction.
Which nervous system controls the involuntary 'fight-or-flight' response?
- A. Sympathetic nervous system
- B. Parasympathetic nervous system
- C. Enteric nervous system
- D. Sensory nervous system
Correct Answer: A
Rationale: The correct answer is the sympathetic nervous system. The sympathetic nervous system is responsible for activating the body's response to stress or danger, leading to the 'fight-or-flight' response. It prepares the body for action by increasing heart rate, dilating pupils, and redirecting blood flow to muscles. Choice B, the parasympathetic nervous system, is responsible for the body's 'rest-and-digest' activities, which are opposite to the 'fight-or-flight' response. Choice C, the enteric nervous system, primarily regulates the gastrointestinal system and is not directly involved in the 'fight-or-flight' response. Choice D, the sensory nervous system, transmits sensory information from the body to the central nervous system and is not responsible for the physiological changes associated with the 'fight-or-flight' response.
Which of the following is NOT a typical component of healthy semen?
- A. Sperm
- B. Fructose (sugar)
- C. Prostaglandins
- D. Urine
Correct Answer: D
Rationale: Healthy semen is composed of sperm, fructose (sugar), and prostaglandins. Urine is not a typical component of semen. While semen is ejaculated during sexual activity, urine is expelled through a separate pathway in the male reproductive system. Therefore, the correct answer is 'Urine.' Choices A, B, and C are all components found in healthy semen.