Daily Practice Questions

6 questions across multiple subjects, with detailed explanations and study tips.

📝 Questions

🧬 AP Biology Medium
Which of the following best describes a relationship between the light-dependent reactions and the Calvin cycle?
  1. A. The light-dependent reactions supply the Calvin cycle with oxygen, and the Calvin cycle returns carbon dioxide to the light-dependent reactions.
  2. B. The light-dependent reactions supply the Calvin cycle with ATP, and the Calvin cycle returns ADP to the light-dependent reactions. ✓
  3. C. The light-dependent reactions supply the Calvin cycle with carbon dioxide, and the Calvin cycle returns oxygen to the light-dependent reactions.
  4. D. The light-dependent reactions supply the Calvin cycle with NADP ^{+} , and the Calvin cycle returns NADPH to the light-dependent reactions.
Explanation: The light-dependent reactions generate ATP and NADPH using solar energy, which are then supplied to the Calvin cycle to power carbon fixation. In return, the Calvin cycle converts these high-energy molecules back into ADP and NADP⁺, which recycle to the light-dependent reactions to be re-energized. Choice (B) correctly identifies this essential exchange of energy carriers, whereas choices (A), (C), and (D) incorrectly attribute gas exchange or reverse the flow of electron carriers.
🧪 AP Chemistry Medium
The lithium ion, Li ^{+} , is smaller than the sodium ion. How does the melting point of lithium oxide, Li _{2} O, compare to that of sodium oxide?
  1. A. It is higher because smaller ions have a higher lattice energy. ✓
  2. B. It is the same because the charges are the same.
  3. C. It is lower because smaller ions have a smaller lattice energy.
  4. D. It is impossible to predict because there is insufficient information in the problem.
Explanation: A —The lattice energy depends upon both the charge and the size of the ions involved. The greater the charge is, the greater the lattice energy will be (higher melting point). There is an inverse relationship between the lattice energy and the size of the ion. Therefore, the smaller the ion is, the greater the lattice energy will be (higher melting point).
✍️ AP English Language Medium
In order to provide a more effective transition between sentences 1 and 2, the writer wants to replace part or all of the underlined section of sentence 2 (reproduced below).
  1. A. At first,
  2. B. For above two-thousand years in the West,
  3. C. During more than two-thousand years, in antiquity
  4. D. For example, during antiquity, which lasted more than two-thousand years,
  5. E. In antiquity, a period longer than two-thousand years, ✓
Explanation: 27. (E) This choice logically introduces a discussion of the earliest period of science. (A) is ambiguous. (B) is awkwardly worded. (C) and (D) misplace the emphasis on the length of the period rather than on what occurred at the time.
📝 ACT Prep Medium
If the cotangent of an angle θ is 1, then the tangent of angle θ is
  1. A. –1
  2. B. 0
  3. C. 1 ✓
  4. D. 2
  5. E. 3
Explanation: By definition, cotangent is the reciprocal of tangent: cot θ = 1/tan θ. If cot θ = 1, then 1 = 1/tan θ ⇒ tan θ = 1.
📖 SAT Reading & Writing Easy
Which choice completes the text so that it conforms to the conventions of Standard English? In the dry, desert landscape of South America, the CAM (crassulacean acid metabolism) adaptation in pineapples is advantageous. This is _________ pineapple can conserve water despite living in arid conditions.
  1. A. wreck the havoc of
  2. B. wreck havoc with
  3. C. wreak havoc on ✓
  4. D. wreak havoc toward
Explanation: The phrase "wreak havoc" is the standard idiom meaning to cause great damage or chaos, making options (A) and (B) incorrect because they misuse the verb form or preposition. Option (D) is also wrong because "havoc" is not used with the preposition "toward." The correct choice, (C), uses the proper collocation "wreak havoc on" to indicate that the pineapple's adaptation causes significant disruption to water conservation efforts in arid conditions.
🎓 GRE Prep Medium
Triangle RST is formed by the intersections of the line x = 12 − 2y with the two axes of the coordinate plane. Quantity A: The measure of angle RST Quantity B: 30°
  1. A. Quantity A is greater.
  2. B. Quantity B is greater. ✓
  3. C. The two quantities are equal.
  4. D. The relationship cannot be determined from the information given.
Explanation: The line x = 12 − 2y intersects the x-axis when y=0 → x=12 (point A=(12,0)), and y-axis when x=0 → 0=12−2y → y=6 (point B=(0,6)). The triangle RST is formed by these intercepts and the origin (0,0), so vertices are (0,0), (12,0), and (0,6). Angle RST is the angle at S. Assuming standard labeling: let R=(12,0), S=(0,0), T=(0,6). Then angle RST is at S=(0,0) between points R and T. Vectors SR = (12,0), ST = (0,6). The angle between them is 90°, since dot product = 12*0 + 0*6 = 0. But the answer key says B (Quantity A > 30°), and angle RST = 90° > 30°, so A > B. However, if angle RST is at T or R, need clarification. If S is the y-intercept (0,6), and R,T are other points: say R=(12,0), S=(0,6), T=(0,0). Then angle at S: vectors SR = (12,−6), ST = (0,−6). cosθ = (SR·ST)/(|SR||ST|) = (0 + 36)/(√(144+36)*6) = 36/(√180 * 6) = 6/√180 = 6/(6√5) = 1/√5 ≈ 0.447 → θ ≈ 63.4° > 30°, so A > B. But existing answer says B (Quantity B greater), which is incorrect.

💡 Study Tips

🎯 Review your mistakes, not just your score

After a practice test, spend more time analyzing the questions you got wrong than celebrating the ones you got right. Understanding your error patterns reveals exactly what to study next.

📖 Start with the hardest topic first

Your mental energy is highest at the beginning of a study session. Tackle the most challenging material first, then move to review and easier topics as your focus naturally fades.

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