Which ocean is largest? A. Atlantic B. Indian C. Pacific D. Arctic Explanation: Pacific Ocean is largest.
Which rock forms from magma below surface? A. Extrusive B. Intrusive C. Sedimentary D. Metamorphic Explanation: Intrusive rocks cool underground.
Which biome is coldest? A. Desert B. Tundra C. Rainforest D. Grassland Explanation: Tundra has extremely low temperatures.
Which system transports nutrients? A. Nervous B. Circulatory C. Respiratory D. Digestive only Explanation: Blood carries nutrients.
Which gas exchange occurs in alveoli? A. O₂ out, CO₂ in B. CO₂ out, O₂ in C. Both out D. None Explanation: Oxygen diffuses into blood, CO₂ out.
Which organ detoxifies chemicals? A. Heart B. Liver C. Kidney D. Lung Explanation: Liver metabolizes toxins.
Which process produces variation? A. Mitosis B. Meiosis C. Binary fission D. Budding Explanation: Meiosis introduces recombination.
Which cell type lacks nucleus? A. Neuron B. RBC C. WBC D. Muscle cell Explanation: Mature RBCs lack nucleus.
Which structure is site of protein synthesis? A. Nucleus B. Ribosome C. Lysosome D. Golgi Explanation: Ribosomes assemble amino acids.