NEET General 3 — Questions and Answers
Question 1: Which law states that the pressure of a gas is inversely proportional to its volume at constant temperature?
- Charles's Law
- Avogadro's Law
- Boyle's Law (Correct answer)
- Gay-Lussac's Law
Correct answer: Boyle's Law
Boyle's Law states P₁V₁ = P₂V₂ at constant temperature, showing an inverse relationship between pressure and volume.
Question 2: During which phase of meiosis does crossing over (recombination) typically occur?
- Prophase I (Correct answer)
- Metaphase II
- Anaphase I
- Telophase II
Correct answer: Prophase I
Crossing over occurs during Prophase I when homologous chromosomes pair up as bivalents and exchange genetic segments at chiasmata.
Question 3: What is the hybridization of carbon in ethylene (C₂H₄)?
- sp
- sp² (Correct answer)
- sp³
- sp³d
Correct answer: sp²
Each carbon in ethylene forms a double bond using sp² hybrid orbitals, leaving one unhybridized p orbital for the π bond.
Question 4: A car moving at 20 m/s brakes and stops in 4 seconds. What is the magnitude of its deceleration?
- 2.5 m/s²
- 4 m/s²
- 5 m/s² (Correct answer)
- 80 m/s²
Correct answer: 5 m/s²
Using a = (v - u)/t = (0 - 20)/4 = -5 m/s², so the magnitude of deceleration is 5 m/s².
Question 5: Which enzyme unwinds the DNA double helix during replication?
- DNA polymerase
- Ligase
- Helicase (Correct answer)
- Primase
Correct answer: Helicase
Helicase breaks hydrogen bonds between base pairs, unwinding and separating the two DNA strands at the replication fork.
Question 6: Which of the following is a noble gas with the electron configuration [Ar] 3d¹⁰ 4s² 4p⁶?
- Argon
- Krypton (Correct answer)
- Xenon
- Neon
Correct answer: Krypton
Krypton has the electron configuration [Ar] 3d¹⁰ 4s² 4p⁶, placing it in Period 4 of the noble gases.
Question 7: Which vitamin is synthesized in human skin upon exposure to sunlight?
- Vitamin A
- Vitamin B12
- Vitamin C
- Vitamin D (Correct answer)
Correct answer: Vitamin D
UV-B radiation from sunlight converts 7-dehydrocholesterol in the skin to Vitamin D₃ (cholecalciferol).
NEET General 3
Which law states that the pressure of a gas is inversely proportional to its volume at constant temperature?