1. The term "double circulation" in the cardiovascular system refers to

A. The separation of oxygenated and deoxygenated blood flow within the heart.
B. The regulation of blood pressure through vasoconstriction and vasodilation
C. The cyclic contraction and relaxation of the heart muscle.
D. The existence of two separate circulatory pathways, one for the lungs and one for the body.

Correct answer: D

Rationale: The term 'double circulation' in the cardiovascular system refers to the existence of two separate circulatory pathways, one for the lungs (pulmonary circulation) and one for the body (systemic circulation). In pulmonary circulation, deoxygenated blood is pumped from the heart to the lungs to pick up oxygen and release carbon dioxide. Then, oxygenated blood returns to the heart to be pumped out to the rest of the body in systemic circulation. This separation of oxygenated and deoxygenated blood flow in different pathways is what distinguishes the double circulation system. Therefore, option D is the correct answer as it accurately describes the concept of double circulation in the cardiovascular system.

2. What is the process of converting ammonia, a byproduct of protein digestion, into a less toxic form?

A. Deamination
B. Transamination
C. Decarboxylation
D. Hydrolysis

Correct answer: A

Rationale: Rationale: Deamination is the process of removing an amino group from a molecule, such as converting ammonia (NH3) into a less toxic form like urea. Ammonia is a byproduct of protein digestion and needs to be converted into a less toxic form to be excreted from the body. Deamination is a key step in this process, which occurs mainly in the liver through the urea cycle. Transamination involves the transfer of an amino group from one molecule to another, not the removal of an amino group as in deamination. Decarboxylation is the removal of a carboxyl group from a molecule, and hydrolysis is the breakdown of a compound by adding water.

3. What is the term for a hydrocarbon chain with no double or triple bonds between carbon atoms?

A. Saturated
B. Unsaturated
C. Aromatic
D. Alkene

Correct answer: A

Rationale: A saturated hydrocarbon chain has only single bonds between carbon atoms. The other choices are associated with unsaturation or aromaticity.

4. Lymphedema, a chronic condition, occurs when:

A. Lymph nodes become inflamed
B. Lymph vessels become blocked
C. The spleen malfunctions
D. Bone marrow production decreases

Correct answer: B

Rationale: The correct answer is B: "Lymph vessels become blocked." Lymphedema is a chronic condition characterized by swelling due to the accumulation of lymph fluid. This occurs when lymph vessels become blocked, preventing the proper drainage of lymph fluid. Inflammation of lymph nodes (option A) is not the direct cause of lymphedema. The spleen malfunctioning (option C) and bone marrow production decreasing (option D) are not directly related to the development of lymphedema. Understanding the blockage of lymph vessels is crucial in comprehending the pathophysiology of lymphedema.

5. Which of these is NOT a function of the large intestine?

A. Absorbing water and electrolytes
B. Producing vitamins
C. Breaking down fiber
D. Eliminating waste products

Correct answer: B

Rationale: Rationale: A) Absorbing water and electrolytes: The large intestine plays a crucial role in absorbing water and electrolytes from the indigestible food matter that passes through it. This helps in maintaining the body's fluid balance and preventing dehydration. B) Producing vitamins: While the large intestine contains bacteria that can produce some vitamins like vitamin K and certain B vitamins, the primary site for vitamin production is the small intestine and other organs like the liver. C) Breaking down fiber: The large intestine is responsible for breaking down fiber that was not digested in the small intestine. The bacteria in the large intestine ferment fiber, producing short-chain fatty acids that can be used as an energy source by the body. D) Eliminating waste products: One of the main functions of the large intestine is to eliminate waste products, including indigestible food matter, dead cells, and bacteria, from the body in the form of feces.

6. Which property describes a substance's resistance to flow?

A. Density
B. Viscosity
C. Conductivity
D. Reactivity

Correct answer: b

Rationale: Viscosity refers to a substance's resistance to flow. Substances with high viscosity flow slowly, while those with low viscosity flow more easily.