Answer: A. motion parallax
Explanation:
In the phenomenon of motion parallax, objects that are moving at certain speeds across a particular field of vision, would also appear to move at greater speeds if they’re closer to the observer. This remains true even if the object instead of the person is moving
. The phenomenon always arises whether or not the object is moving or that the observer is moving in a manner that is relative to the object’s motion. This is because of the distance the object moves in comparison to the proportion of the observers’ field of view that it traverses. Thus, motion parallax generally describes one’s perception of the position of an object with a three-dimensional space, based on sensing said objects at different positions.
Answer:
The function of B cells is to make antibodies against antigens
Explanation:
bring change in the genetic basis of a population
Answer: Option A. "In front of the patient, pointing at his navel"
Explanation:
The X-ray of abdominal cavity is known as Abdominal x-ray. It has same principle as X-ray and uses ionizing radiation to take pictures of inner parts of abdominal cavity such as intestine, stomach, liver and spleen. it is used to diagnose patients with vomiting, unexplained pain, and nausea.
While diagnosing patient's abdominal cavity, x-ray technician position the camera in front of the patient, pointing at his navel in order to produce a frontal view of abdominal cavity.
Talking about a x-ray machine, it is a compact apparatus which can be taken to the patient in a hospital bed or the emergency room. The x-ray tube connects flexible arm which further extends towards the patient and an x-ray film holder (image recording) plate is placed under the patient.
The technologist will ask the patient to take position on the x-ray table or bed and will position x-ray machine over the abdominal area of the patient, in order to take the frontal view of abdominal cavity. The patient will be asked to hold their breathe to get a clear picture. The technician will turn on the x-ray machine that allows x-ray machine to produce a small burst of radiation which passes through the abdominal area and records the frontal view of patient's abdominal cavity. As a result, soft tissue shows up in shades of gray and air appears black while bones appear white on the x-ray, through which patient can be diagnosed.
Hence, the correct option is A "In front of the patient, pointing at his navel".
