1. Dense irregular connective tissue, found in tendons and ligaments, provides:

A. Flexibility
B. Lubrication
C. Insulation
D. Tensile strength

Correct answer: D

Rationale: The correct answer is D: 'Tensile strength.' Dense irregular connective tissue is composed of tightly packed collagen fibers arranged in a random pattern, providing resistance to tension forces. This structural arrangement is ideal for tendons and ligaments, as they need to withstand pulling and stretching forces. 'Flexibility' (A) is more characteristic of elastic fibers, 'Lubrication' (B) is provided by synovial fluid in joints, and 'Insulation' (C) is typically associated with adipose tissue. Therefore, tensile strength is the primary function of dense irregular connective tissue in tendons and ligaments.

2. When referring to blood vessel walls, the term "atherosclerosis" describes:

A. The normal process of blood vessel wall thickening with age.
B. The inflammation of the inner lining of blood vessels.
C. The dilation and weakening of a blood vessel wall (aneurysm).
D. The abnormal buildup of plaque within the arterial walls.

Correct answer: D

Rationale: Atherosclerosis is a condition characterized by the abnormal buildup of plaque within the arterial walls. This plaque is made up of substances like cholesterol, calcium, and fatty compounds. Over time, this plaque can harden and narrow the arteries, leading to reduced blood flow and potential complications like heart attacks and strokes. Options A, B, and C do not accurately describe atherosclerosis. Option A is incorrect because atherosclerosis is not a normal aging process but rather a disease. Option B is incorrect because atherosclerosis involves the buildup of plaque rather than inflammation of the inner lining of blood vessels. Option C is incorrect because an aneurysm is a different condition involving the dilation and weakening of a blood vessel wall, not the buildup of plaque seen in atherosclerosis.

3. A car is traveling at a constant speed on a straight road. What is the net force acting on the car?

A. A force equal to its weight pushing upwards
B. A force equal to its weight pushing downwards
C. A force equal to its engine power pushing forward
D. No net force

Correct answer: D

Rationale: Since the car's speed is constant, there is no acceleration, and according to Newton's first law, a net force of zero is required.

4. Which statement best summarizes the main argument of the passage?

A. Smart cities are a revolutionary solution to all urban challenges.
B. Technology alone can fix modern cities' problems.
C. Smart cities offer potential but require careful consideration of data privacy and ethical implications.
D. Traditional city planning methods are superior to implementing smart technology.

Correct answer: C

Rationale: The passage acknowledges both the potential and concerns surrounding smart cities, making it the most accurate summary.

5. What is the difference between DNA and RNA?

A. Both are double-stranded.
B. DNA contains deoxyribose sugar, while RNA contains ribose sugar.
C. RNA contains the nitrogenous base uracil, while DNA contains thymine.
D. Both are identical molecules.

Correct answer: B

Rationale: Rationale: A) Incorrect. DNA is double-stranded, but RNA is typically single-stranded. B) Correct. DNA contains deoxyribose sugar, which lacks an oxygen atom on the 2' carbon of the sugar ring, while RNA contains ribose sugar, which has an additional hydroxyl group on the 2' carbon. C) Incorrect. RNA contains the nitrogenous base uracil, while DNA contains thymine. D) Incorrect. DNA and RNA have distinct structures and functions, so they are not identical molecules.