Nokea
Which structure in the body is responsible for detecting light and converting it into signals for the brain?
- A. Iris
- B. Retina
- C. Lens
- D. Pupil
Correct Answer: B
Rationale: The correct answer is the Retina. The retina in the eye contains specialized cells called photoreceptors that detect light and convert it into neural signals. These signals are then transmitted to the brain via the optic nerve for visual processing. The iris is responsible for controlling the amount of light entering the eye by adjusting the size of the pupil, while the lens helps focus light onto the retina. The pupil is simply the opening in the center of the iris that allows light to enter the eye.
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Which part of the digestive system is responsible for absorbing nutrients?
- A. Esophagus
- B. Stomach
- C. Small intestine
- D. Large intestine
Correct Answer: C
Rationale: The small intestine is the correct answer because it is the primary site for nutrient absorption in the digestive system. It contains specialized structures such as villi and microvilli that maximize the absorption of nutrients from digested food. The esophagus is responsible for transporting food from the mouth to the stomach; the stomach primarily aids in digestion by secreting enzymes and acids; and the large intestine mainly absorbs water and electrolytes from the remaining indigestible food matter. Therefore, the small intestine plays a crucial role in absorbing essential nutrients for the body's functions, making it the correct choice in this context.
Which of the following nerves has the longest axon in the human body?
- A. Dorsal root ganglion
- B. Laryngeal nerve
- C. Sciatic nerve
- D. None of the above
Correct Answer: C
Rationale: The sciatic nerve contains the longest axon in the human body, extending from the lower back down the leg. This nerve is responsible for innervating the muscles of the lower limb. The dorsal root ganglion and laryngeal nerve do not possess axons as long as the sciatic nerve, making them incorrect choices. Therefore, the correct answer is C, the sciatic nerve.
Which type of blood cell is responsible for carrying oxygen?
- A. White blood cell
- B. Red blood cell
- C. Platelet
- D. Plasma
Correct Answer: B
Rationale: The correct answer is B: Red blood cell. Red blood cells, also known as erythrocytes, are responsible for carrying oxygen from the lungs to the body's tissues. They contain hemoglobin, a protein that binds to oxygen and transports it throughout the body. White blood cells (Choice A) are part of the immune system and help fight infections, not involved in carrying oxygen. Platelets (Choice C) are responsible for blood clotting, not oxygen transport. Plasma (Choice D) is the liquid component of blood that carries various substances like nutrients and waste products, but it does not directly carry oxygen.
Which of the following infectious diseases can be caused by a protozoan parasite?
- A. Measles
- B. Malaria
- C. Mumps
- D. Mononucleosis
Correct Answer: B
Rationale: The correct answer is B: Malaria. Malaria is caused by Plasmodium, a protozoan parasite transmitted through the bite of infected mosquitoes. Measles and mumps are viral diseases caused by separate viruses. Mononucleosis, on the other hand, is caused by the Epstein-Barr virus, which is also a viral infection. Therefore, choices A, C, and D are incorrect as they are caused by viruses, not protozoa.
Which of the following joints is an example of a hinge joint?
- A. Hip joint
- B. Elbow joint
- C. Shoulder joint
- D. Knee joint
Correct Answer: B
Rationale: The correct answer is B: Elbow joint. A hinge joint allows movement primarily in one plane, enabling bending and straightening actions. The elbow joint specifically functions as a hinge joint, facilitating the bending and straightening of the arm. The other options, such as the hip joint (A), shoulder joint (C), and knee joint (D), are not examples of hinge joints as they allow movement in multiple planes with more complex motions.