Natural Science MCQs

Questions and Answers (121–150)

121. Which organelle is known as the powerhouse of the cell?

Answer: Mitochondria

122. What is the main function of red blood cells?

Answer: Transport of oxygen

123. Which element has the atomic number 1?

Answer: Hydrogen

124. What is the unit of acceleration?

Answer: Meter per second squared (m/s²)

125. Which layer of the atmosphere contains weather phenomena?

Answer: Troposphere

126. What is the largest organ of the human body?

Answer: Skin

127. Which gas protects Earth from ultraviolet radiation?

Answer: Ozone

128. What is the study of microorganisms called?

Answer: Microbiology

129. Which organelle contains genetic material?

Answer: Nucleus

130. Which scientist discovered penicillin?

Answer: Alexander Fleming

131. What type of energy does the Sun produce?

Answer: Solar energy

132. What is the process of converting solid directly into gas?

Answer: Sublimation

133. Which gas is used in photosynthesis?

Answer: Carbon dioxide

134. What is the SI unit of momentum?

Answer: kg·m/s

135. Which metal is the lightest?

Answer: Lithium

136. What is the largest planet in the solar system?

Answer: Jupiter

137. Which organ stores bile in the human body?

Answer: Gallbladder

138. Which instrument is used to measure humidity?

Answer: Hygrometer

139. What is the chemical symbol for iron?

Answer: Fe

140. Which vitamin is essential for healthy bones?

Answer: Vitamin D

141. Which part of the plant transports food?

Answer: Phloem

142. What is the SI unit of electric resistance?

Answer: Ohm

143. Which blood component helps in clotting?

Answer: Platelets

144. Which process converts liquid water into vapor?

Answer: Evaporation

145. Which planet is known as the Red Planet?

Answer: Mars

146. Which organ controls the nervous system?

Answer: Brain

147. What is the study of rocks called?

Answer: Petrology

148. Which element is necessary for plant growth and chlorophyll production?

Answer: Magnesium

149. What is the SI unit of heat?

Answer: Joule

150. What is the branch of science that studies heredity?

Answer: Genetics