Daily Practice Questions

Explanation: The endosymbiosis hypothesis proposes that mitochondria and chloroplasts originated as free-living prokaryotes engulfed by an ancestral eukaryotic cell, which is supported by their circular DNA, ribosomes, and ability to reproduce via binary fission. Choice (D) is the exception because these organelles are not found in all eukaryotic cells; for instance, animal cells lack chloroplasts, and some specialized eukaryotes lack mitochondria entirely. The presence of specific organelles varies by organism type rather than being a universal feature that supports their evolutionary origin.

Explanation: The text describes a mutually beneficial relationship where an occupational therapist helps a client regain function, while the therapist gains professional efficacy; similarly, choice (C) illustrates mutualism where oxpecker birds remove harmful insects from zebras, benefiting both species. This mirrors the collaborative dynamic in the passage where both parties improve their condition through interaction. In contrast, choices (A), (B), and (D) describe one-sided consumption or specific behavioral roles that do not capture the reciprocal benefit central to the text's argument.

Explanation: Using the Pythagorean theorem, we find the distance between A(2,2) and B(5,6). The horizontal distance is (5 – 2) = 3, and the vertical distance is (6 – 2) = 4. The distance is √(3² + 4²) = √(9 + 16) = √25 = 5.

Explanation: is best because it is written in standard English. The other choices are flawed by such weaknesses as awkward, unidiomatic expression, lack of parallelism, faulty comparison, and redundancy. (Whether the statement proves the speaker’s point is another matter.)

Explanation: To make the quantities easier to compare, make them look more alike. Use FOIL to multiply out Quantity A: (r + 3)(s + 2) = rs + 2r + 3s + 6. Now, both quantities have terms rs and a number, so you can subtract Quantity B, rs + 12, from both quantities to make Quantity A 2r + 3s − 6. After the subtraction, Quantity B is zero. If 2r + 3s − 6 is positive, Quantity A is greater than Quantity B; if 2r + 3s − 6 is negative, Quantity B is greater than Quantity A. Since there are no restrictions on the values of r and s, either case could be true and (D) is correct. You could also use Picking Numbers. For example, let r = 2 and s = 3. Then Quantity A is (2 + 3)(3 + 2) = 25 and Quantity B is (2 × 3) + 12 = 18. In this case, Quantity A is greater. But if you let r = −3 and s = −2, Quantity A will be 0 while Quantity B will still be 18, making Quantity B greater. Once again, you have demonstrated that a definite relationship cannot be determined.

Explanation: The correct answer is (C) because it accurately describes the standard forward propagation process in an artificial neural network, where data flows sequentially from input units through hidden layers to output units for comparison or prediction. This linear progression aligns with the fundamental architecture of feedforward networks, which do not loop back to alter input units as suggested in choices (B) and (E). Options (A) and (D) are incorrect because they imply a direct connection between inputs and outputs that bypasses hidden layers, ignoring the network's primary mechanism of processing information through intermediate stages.