1. The measurable electrical activity of the brain is recorded by a:

A. CAT scan
B. MRI scan
C. Electroencephalogram (EEG)
D. X-ray

Correct answer: C

Rationale: The correct answer is C: "Electroencephalogram (EEG)". An EEG is a non-invasive test that measures the electrical activity of the brain by placing electrodes on the scalp. It is specifically designed to record brain wave patterns, making it a valuable tool in diagnosing conditions such as epilepsy, sleep disorders, and brain injuries. A CAT scan (A) and MRI scan (B) are imaging techniques that show the structure of the brain, while an X-ray (D) is not typically used to measure brain electrical activity.

2. When does work on an object occur?

A. Only when the object's velocity changes
B. Only when a force is applied to the object
C. Whenever there is a force exerted on the object causing displacement
D. Only when the object is lifted vertically

Correct answer: c

Rationale: Work is done when a force is applied to an object, causing it to move in the direction of the force.

3. Which part of the brain controls balance and coordination?

A. Cerebellum
B. Hypothalamus
C. Occipital lobe
D. Corpus callosum

Correct answer: A

Rationale: Rationale: The cerebellum is the part of the brain responsible for coordinating voluntary movements, balance, and posture. It receives information from the sensory systems, the spinal cord, and other parts of the brain to regulate motor movements. The hypothalamus is involved in regulating various bodily functions such as temperature, hunger, and thirst. The occipital lobe is primarily responsible for processing visual information. The corpus callosum is a structure that connects the two hemispheres of the brain and facilitates communication between them.

4. Which of the following structures is responsible for preventing the backflow of blood from the left ventricle into the left atrium?

A. Aortic valve
B. Pulmonary valve
C. Tricuspid valve
D. Mitral valve

Correct answer: D

Rationale: The correct answer is D, the mitral valve. The mitral valve, also known as the bicuspid valve, is located between the left atrium and the left ventricle. Its main function is to prevent the backflow of blood from the left ventricle into the left atrium during ventricular contraction. The aortic valve (A) is responsible for preventing the backflow of blood from the aorta into the left ventricle, the pulmonary valve (B) prevents backflow from the pulmonary artery into the right ventricle, and the tricuspid valve (C) prevents backflow from the right ventricle into the right atrium. Therefore, the mitral valve is specifically responsible for preventing backflow in the left side of the heart, making it the correct answer in this case.

5. Which type of reaction is represented by the equation A + B â†’ AB?

A. Synthesis
B. Decomposition
C. Single Replacement
D. Double Replacement

Correct answer: a

Rationale: Synthesis reactions involve the combination of two or more substances to form a new compound.

6. Antidiuretic hormone (ADH) plays a crucial role in regulating water balance. When ADH levels are high, what happens to urine production?

A. Urine production increases significantly
B. Urine production decreases to conserve water
C. There is no change in urine production
D. The kidneys stop producing urine altogether

Correct answer: B

Rationale: When antidiuretic hormone (ADH) levels are high, it indicates that the body needs to conserve water. ADH works by increasing the permeability of the collecting ducts in the kidneys, allowing more water to be reabsorbed back into the bloodstream. This action leads to a decrease in urine production, as the body retains more water to maintain proper fluid balance. Therefore, the correct answer is B: 'Urine production decreases to conserve water.' High levels of ADH help the body prevent dehydration by reducing the amount of water lost in urine.