Free Biological Importance of Water MCQs with Answers
87 Biological Importance of Water MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Water supports life through its polarity, hydrogen bonding and ability to dissolve ionic and polar substances. Its high specific heat, heat of vaporization, cohesion, adhesion and incompressibility help regulate temperature, transport materials and maintain structure, while hydrolysis and osmosis depend directly on water.
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- A. Soluble
- B. Insoluble
- C. Partially soluble
- D. Depends upon condition
Explanation: Nonpolar molecules do not form favourable interactions with polar water molecules, so they are generally insoluble and tend to aggregate…
Correct answer: Insoluble42. The survival of an animal depends upon its ability to take some from its environment____________?
- A. Chemicals
- B. Hydrocarbons
- C. Organic molecules
- D. Inorganic molecules
Explanation: Animals depend on obtaining organic molecules from the environment because these molecules supply energy and raw materials for growth…
Correct answer: Organic molecules- A. Carbohydrates
- B. Fatty acid
- C. Water
- D. Protein
Explanation: Water acts as a lubricant in joints and other body surfaces, reducing friction and protecting tissues from mechanical damage.
Correct answer: Water- A. Burst
- B. Be Killed
- C. Be deplasmolysed
- D. Show no change in it
Explanation: Water enters a plasmolysed plant cell by osmosis because the cell sap has a lower water potential than the surrounding water.
Correct answer: Be deplasmolysed- A. Protein
- B. NaCl
- C. Water
- D. Cholesterol
Explanation: Water forms about 90 to 92% of blood plasma and acts as the solvent in which proteins, salts, nutrients, hormones and wastes are…
Correct answer: Water- A. Ionic as well as non ionic substance in aqueous media retains their identity
- B. Enzymes can not perform catalysis reaction in this medium
- C. Ions and molecules move randomly thus are in more favorable state to react with other molecules and ions
- D. It is less favorable media for chemical reactions
Explanation: In an aqueous medium, dissolved ions and molecules move freely and randomly, increasing the opportunities for effective collisions and…
Correct answer: Ions and molecules move randomly thus are in more favorable state to react with other molecules and ions- A. Specific Heat of Vaporization
- B. Specific Heat capacity
- C. Caloric Heat
- D. Both A and C
Explanation: The heat needed to raise 1 g of water by 1 °C is one calorie, and this illustrates water's specific heat capacity, 1 cal/g°C.
Correct answer: Specific Heat capacity- A. High specific heat of vaporization
- B. High specific heat capacity
- C. Its Dipole nature
- D. Its liquid state
Explanation: Water has a high specific heat capacity, so it absorbs or releases considerable heat with only a small change in its own temperature.
Correct answer: High specific heat capacity49. Conversion of ammonia or ammonium ion into nitrites during nitrogen cycle occurs due_____________?
- A. Rhizobium
- B. Nitrosomonas
- C. Nitrobacter
- D. Pseudomonas
Explanation: Nitrosomonas carries out the first nitrification step, oxidizing ammonia or ammonium ions into nitrites.
Correct answer: Nitrosomonas- A. More than 2500 mm
- B. 750-1500 mm
- C. 250-750 mm
- D. Less than 250 mm
Explanation: Grasslands commonly receive about 250 to 750 mm of rainfall annually, enough to support grasses but usually insufficient for dense…
Correct answer: 250-750 mm- A. CO2
- B. O2
- C. Water
- D. Nutrients
Explanation: Aquatic ecosystem productivity depends strongly on available light for photosynthesis and on nutrients such as nitrates and phosphates…
Correct answer: Nutrients- A. Tropical rain forest
- B. Temperate deciduous forest
- C. Grassland
- D. Tundra
Explanation: Pakistan contains grasslands, temperate deciduous forests and cold high-altitude regions that may be classified as tundra, but it does not…
Correct answer: Tropical rain forest- A. Air
- B. Water
- C. Land
- D. Gravity
Explanation: Gravity is a highly constant abiotic factor because its strength does not vary substantially across the ordinary habitats of an ecosystem…
Correct answer: Gravity- A. Hydrogen bonding
- B. Transpiration
- C. Adhesion
- D. Root prerssure
Explanation: Transpiration creates negative pressure in the leaf and pulls the continuous water column upward through xylem under the cohesion-tension…
Correct answer: Transpiration- A. 10%
- B. 30%
- C. 75%
- D. 90%
Explanation: Approximately 71% of Earth's surface is covered by water, and this is conventionally rounded to about 75% in many biology texts.
Correct answer: 75%- A. 65%
- B. 18%
- C. 10%
- D. 3%
Explanation: Oxygen is the most abundant element in the human body by mass, contributing about 65%, largely because it is present in body water and…
Correct answer: 65%- A. 20%
- B. 65%
- C. 85%
- D. 89%
Explanation: Brain tissue contains a high proportion of water, commonly given in introductory biology as about 85%, because water forms the medium for…
Correct answer: 85%- A. Iron
- B. Hydrogen
- C. Chlorine
- D. Copper
Explanation: Hydrogen is a macronutrient because plants require it in relatively large amounts, mainly as part of water and organic compounds.
Correct answer: Hydrogen- A. Polarity
- B. Cohesion
- C. Heat of vaporization
- D. Specific heat capacity
Explanation: The correct answer is polarity. Water molecules have a polar structure, meaning there is an uneven distribution of electron density.
Correct answer: Polarity- A. Being an excellent solvent
- B. Cooling agent
- C. Membrane stabilizer
- D. Thermal shock resistor
Explanation: Due to its high heat capacity, water is used by warm blooded animals to more evenly disperse heat in their bodies; it acts in a similar…
Correct answer: Cooling agent