Which part of the brain is responsible for balance and coordination?
- A. Cerebellum
- B. Cerebrum
- C. Medulla oblongata
- D. Hypothalamus
Correct Answer: A
Rationale: The correct answer is the cerebellum. The cerebellum, situated at the back of the brain, is responsible for coordinating voluntary movements and maintaining balance and posture. It receives information from the sensory systems, the spinal cord, and other parts of the brain to regulate motor movements. The cerebrum (choice B) is responsible for higher brain functions such as thinking and decision-making, the medulla oblongata (choice C) controls vital autonomic functions like breathing and heart rate, and the hypothalamus (choice D) is involved in regulating basic biological needs like hunger, thirst, and body temperature.
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Where is the genetic material located within a cell?
- A. Nucleus
- B. Mitochondria
- C. Ribosome
- D. Golgi apparatus
Correct Answer: A
Rationale: The genetic material, which is composed of DNA, is primarily located in the nucleus of a cell. The nucleus serves as the control center of the cell, housing the genetic information that directs the cell's functions and characteristics. Choice B (Mitochondria), C (Ribosome), and D (Golgi apparatus) are incorrect because while these cellular components play essential roles in the cell, they do not house the genetic material. Mitochondria are known as the powerhouse of the cell, responsible for energy production; ribosomes are involved in protein synthesis, and the Golgi apparatus is responsible for processing and packaging proteins for transport.
Which part of the eye is responsible for color vision?
- A. Cornea
- B. Iris
- C. Retina
- D. Lens
Correct Answer: C
Rationale: The correct answer is option C: Retina. The retina contains photoreceptor cells, including cones that are responsible for color vision. Cones are sensitive to different wavelengths of light, allowing us to perceive and differentiate various colors.
Choice A, Cornea, is the transparent outer layer of the eye that helps focus light. It does not play a direct role in color vision.
Choice B, Iris, is the colored part of the eye that controls the size of the pupil and regulates the amount of light entering the eye. While it is essential for adjusting light levels, it is not directly involved in color vision.
Choice D, Lens, is responsible for focusing light onto the retina. It helps to form clear images on the retina but does not play a role in color vision.
Which hormone is responsible for the regulation of calcium levels in the blood?
- A. Insulin
- B. Parathyroid hormone
- C. Cortisol
- D. Melatonin
Correct Answer: B
Rationale: Parathyroid hormone, produced by the parathyroid glands, is responsible for regulating calcium levels in the blood. It achieves this by increasing calcium absorption in the intestines and kidneys, thus maintaining appropriate calcium levels in the bloodstream. Insulin is involved in glucose metabolism, not calcium regulation. Cortisol is a stress hormone that affects various body functions but not calcium levels. Melatonin is responsible for regulating the sleep-wake cycle, not calcium levels.
Which type of muscle tissue is voluntary?
- A. Cardiac muscle
- B. Skeletal muscle
- C. Smooth muscle
- D. Striated muscle
Correct Answer: B
Rationale: The correct answer is B, Skeletal muscle. Skeletal muscle is a type of voluntary muscle tissue, allowing conscious control over its movement. Unlike smooth and cardiac muscle, which are involuntary, skeletal muscle is under direct voluntary control. Cardiac muscle (choice A) is involuntary and found in the heart. Smooth muscle (choice C) is also involuntary and found in the walls of internal organs. While skeletal muscle is striated (contains stripes), choice D is not the best answer as it does not specifically address the voluntary nature of skeletal muscle.
What type of joint is found in the elbow?
- A. Ball and socket joint
- B. Hinge joint
- C. Pivot joint
- D. Saddle joint
Correct Answer: B
Rationale: The correct answer is a hinge joint. The elbow joint is a hinge joint that allows for flexion and extension movements, much like the movement of a door hinge. This type of joint permits movement in one plane, similar to the action of opening and closing a door. The other choices are incorrect:
A) Ball and socket joints allow for a wide range of motion in multiple directions, such as the hip and shoulder joints.
C) Pivot joints allow rotation around a single axis, like the joint at the top of the neck that allows the head to turn from side to side.
D) Saddle joints are found in the thumb and have a biaxial range of motion allowing flexion, extension, adduction, abduction, and circumduction.