Physics Chemistry & Biology Test 8
Which gas makes the Sun shine ?
  • Helium
  • Oxygen
  • Nitrogen
Explanation: The Sun produces energy through a process called nuclear fusion, where hydrogen atoms fuse together to form helium. This reaction releases a tremendous amount of light and heat energy, which makes the Sun shine.
Plants prepare food by which process ?
  • Respiration
  • Photosynthesis
  • Transpiration
  • Fermentation
Explanation: Plants make their own food through photosynthesis, a process that takes place in the chloroplasts using chlorophyll. In this process, plants use sunlight, carbon dioxide (CO₂), and water (H₂O) to produce glucose (food) and oxygen (O₂).
What is the Sl unit of temperature ?
  • Watt
  • Joule
  • Kelvin
  • Celsius
Explanation: The SI unit of temperature is Kelvin (K). It is an absolute scale starting from absolute zero (0 K), the point where particles have minimum thermal motion. Celsius (°C) is commonly used, but the standard SI unit is Kelvin.
What is the full form of DNA ?
  • Deoxyribonucleic Acid
  • Dioxyribonucleic Acid
  • Dual Nucleic Acid
  • Deoxynucleic Atom
Explanation: DNA (Deoxyribonucleic Acid) is the molecule that carries genetic information in living organisms. It contains instructions for growth, development, functioning, and reproduction of all known living beings.
Red color of blood is due to which pigment ?
  • RBC
  • WBC
  • Hemoglobin
  • Iron
Explanation: The red color of blood comes from hemoglobin, a protein pigment in red blood cells (RBCs). Hemoglobin contains iron and binds with oxygen, giving blood its bright red color when oxygenated and dark red when deoxygenated.
What is the outermost layer of Earth called ?
  • Core
  • Mantle
  • Crust
  • Lithosphere
  • Core
  • Mantle
    • Explanation: The Earth’s outermost layer is the crust. It is a thin, solid layer where we live. Beneath the crust lies the mantle, followed by the core. The crust includes continental crust (land) and oceanic crust (beneath oceans).