Answer: (D) Lecithin
Explanation: Proteins are large, complex molecules that play many critical roles in the body, including enzymes, collagen, and hemoglobin. However, lecithin is not a protein; it is a type of phospholipid, which is a fat molecule commonly found in cell membranes. This distinguishes lecithin from the other options, which are all proteins.

Answer: (D) Vitamin B12
Explanation: Folate and Vitamin B12 are essential for nucleic acid synthesis. Folate participates in the synthesis of DNA and RNA, while Vitamin B12 is crucial for the regeneration of folate, which allows the continuation of nucleic acid production. Deficiencies in either of these vitamins can lead to impaired DNA synthesis and cell division.

Answer: (A) ATP
Explanation: ATP (Adenosine Triphosphate) is known as the energy currency of the cell because it stores and provides energy for many biochemical processes. Cells use ATP to power various functions, such as muscle contraction, nerve impulse propagation, and chemical synthesis. When ATP is broken down into ADP (Adenosine Diphosphate), energy is released, which the cell can use for its activities.

Answer: (B) Lipids
Explanation: Lipids, primarily in the form of triglycerides, are the most energy-dense macronutrient and make up about 99% of the body’s energy reserves. While glycogen and glucose are also stored forms of energy, they only account for a small fraction of the total energy storage compared to lipids. Amino acids are primarily used for protein synthesis rather than energy storage.

Answer: (C) Radiation
Explanation: Radiation is the process by which heat is transferred as electromagnetic waves, specifically infrared energy, between objects that are not in direct physical contact.

Answer: (A) Vitamin D deficiency
Explanation: Osteomalacia is primarily caused by a deficiency in Vitamin D, which is essential for calcium absorption in the bones. Without adequate Vitamin D, bones can become soft and weak.

Answer: (B) Liver and muscles
Explanation: Glycogen is primarily stored in the liver and muscles as a form of energy reserve, which can be quickly mobilized to meet energy demands.

Answer: (A) Folic acid
Explanation: Anemia in humans is commonly caused by a deficiency of folic acid, which is essential for the production of red blood cells.

Answer: (D) Spinach
Explanation: Spinach is a leafy green vegetable that is well-known for its high iron content, making it a rich source of this essential mineral.

Answer: (D) All of Them
Explanation: All of the listed substances—beta carotene, lutein, and lycopene—are antioxidants. Antioxidants help protect the body from damage caused by harmful molecules known as free radicals.