Nokea
What is the function of the myelin sheath for a nerve cell?
- A. Sensory perception
- B. Insulation
- C. Nutrition
- D. Regeneration
Correct Answer: B
Rationale: The myelin sheath functions as an insulator for nerve cells, enabling the rapid transmission of electrical impulses along the nerve fiber. This insulation is essential for maintaining the speed and efficiency of nerve signal conduction. Sensory perception involves detecting sensory stimuli, nutrition involves the supply of nutrients, and regeneration is the process of regrowth or repair, which are distinct functions from what the myelin sheath provides.
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Which process involves the maturation and release of a representative egg from an ovarian follicle?
- A. Oogenesis
- B. Fertilization
- C. Ovulation
- D. Menstruation
Correct Answer: C
Rationale: Ovulation is the process where a mature ovarian follicle releases an egg. This egg is the female gamete awaiting fertilization in the fallopian tube. Oogenesis refers to the complete process of egg cell development, fertilization is the merging of egg and sperm, and menstruation is the shedding of the uterine lining in the absence of pregnancy.
To accurately measure the density of a series of small irregular solids made of plastic, wood, fiberglass, and glass, which of the following laboratory tools will a student need?
- A. Graduated cylinder, water, weighing balance
- B. Weighing balance, Bunsen burner, metric ruler
- C. Graduated cylinder, spectrophotometer, water
- D. Graduated beaker, metric ruler, water
Correct Answer: A
Rationale: To measure the density of irregular solids, a student needs a graduated cylinder to measure the volume of the solids by water displacement, water for the displacement method, and a weighing balance to measure the mass of the solids. Density is calculated by dividing the mass by the volume.
In experimental design, which group can be measured against the experimental group as a standard of comparison?
- A. Control
- B. Responding
- C. Manipulated
- D. Variable
Correct Answer: A
Rationale: The control group is a critical component in experimental design as it serves as a reference point for comparison with the experimental group. The control group does not receive the experimental treatment but is subjected to all other conditions. By comparing the outcomes of the experimental group with those of the control group, researchers can evaluate the impact and efficacy of the experimental treatment.
Which of the following describes one difference between skeletal and cardiac muscles?
- A. Cardiac muscles are involuntary, whereas skeletal muscles are voluntary
- B. Skeletal muscles are not autorhythmic, whereas cardiac muscles are
- C. Skeletal muscles are found in the limbs, whereas cardiac muscles are found in the heart
- D. Skeletal muscles are not autorhythmic
Correct Answer: A
Rationale: The correct answer is A because cardiac muscles are involuntary, meaning they are not under conscious control, while skeletal muscles are voluntary, allowing conscious control over their movement. Option B is incorrect as skeletal muscles are not autorhythmic, unlike cardiac muscles. Option C is inaccurate as skeletal muscles are primarily found in the limbs, while cardiac muscles are predominantly located in the heart. Option D is false as skeletal muscles are not autorhythmic; instead, cardiac muscles possess autorhythmicity due to their ability to generate and conduct electrical impulses independently.
Which of the following pathways best represents the flow of blood from the human heart to organs?
- A. Blood pumped from the heart first enters arteries that then narrow to form arterioles that deliver blood to capillaries of the organs
- B. Blood pumped from the heart first enters veins that then narrow to form venules that deliver blood to arteries of the organ
- C. Blood pumped from the heart first enters arteries that then narrow to form arterioles that deliver blood to capillaries of the organs
- D. Blood pumped from the heart first enters arteries that then narrow to form veins that deliver blood to the organs
Correct Answer: C
Rationale: The correct pathway for the flow of blood from the human heart to organs involves a series of blood vessels. Blood is pumped from the heart into large arteries, which then branch into smaller arterioles. These arterioles deliver blood to capillaries located in the organs. Capillaries are essential for the exchange of nutrients, gases, and waste products between the blood and the tissues. This intricate network ensures efficient delivery of oxygen and nutrients to the organs and removal of waste products. Therefore, the correct sequence is for blood to flow from the heart, through arteries, then arterioles, and finally to capillaries in the organs for optimal exchange and organ function.