The human body can last weeks without food, but only days without water. The body is made up of 50 to 75 per cent water. Water forms the basis of blood, digestive juices, urine and perspiration, and is contained in lean muscle, fat and bones. It helps to maintain the temperature of the body.

Chloroplasts are green because they contain the green pigment chlorophyll in their thylakoid membranes. Chlorophyll is a pigment that absorbs red and blue light. So plants are green because chlorophyll reflects green light. 

Glucose is a simple monosaccharide sugar. It is a hexose sugar. It is an aldose sugar. Ingested carbohydrates are broken down into monosaccharides which are absorbed in the intestine. Glucose is absorbed in intestine. Glucose is also chief form of sugar in blood and circulates in blood to supply energy to visceral organs.

Calcium strengthens bones and teeth in our body. It is an inorganic substance which is later converted to its organic forms when it gets combined with carbon molecule.

Nutrients obtained by plants and animals are classified into two groups organic and inorganic. Inorganic nutrients are those that are not easily found in animals or plants. They are always converted into their organic forms. Ammonia is an organic nutrient generally found in animals for synthesis of various metabolite.

Nitrogen is one such element which is very important in plant growth because it is an essential part of the chlorophyll that is the site of photosynthesis.

Rhizobium is a nitrogen-fixing bacteria found in symbiotic association with the root nodules of leguminous plants. 

Photosynthesis is a metabolic process of formation of glucose from carbon dioxide and water in presence of light energy.

PPP or pentose phosphate pathway is an important pathway that takes place in the cytoplasm.

 A limiting factor is simply anything in short supply that will limit the rate of photosynthesis. Photosynthesis has 3 limiting factors: light intensity, carbon dioxide concentration, temperature. Sometimes photosynthesis is limited by the concentration of carbon dioxide in the air. Even if there is plenty of light, a plant cannot photosynthesis if there is insufficient carbon dioxide as the light energy cannot be fully absorbed. 

A comparison of elements present in non-living and living matter is given in the table below:

The body burns fat after first exhausting the contents of the digestive tract along with glycogen (carbohydrates) reserves stored in muscle and liver cells. During short periods of energy abstinence, the human body will burn primarily free fatty acids from body fat stores. After prolonged periods of starvation when the body has depleted its body fat, it begins to burn lean tissue and muscle (protein) as a fuel source.

Chemical energy is stored in the bonds that connect atoms with other atoms and molecules with other molecules. Because chemical energy is stored, it is a form of potential energy. When a chemical reaction takes place, the stored chemical energy is released. Chemical Energy - is really a form of potential energy and is the energy stored in food or chemical combinations. Radiant Energy - is a combination of heat and light energy.

• Malnutrition is the condition or state in which the body does not get proper nutrition or get overnutrition (imbalanced nutrition) and as a result a deficiency or excess or imbalanced of energy. 
• Malnutrition is referred to overnutrition resulting from overeating or excessive intake of specific nutrients. 
• The amount of nutrients exceeds the amount required for normal growth, development, and metabolism. Hence, If one's diet exceeds one's need, it is called overnutrition.
  

Option D is the correct answer here.

Protective components of foods are minerals and vitamins. Vegetables like spinach, cabbage, brinjal, beans, and fruits are called protective foods. These components protect us from diseases. Hence, they are called protective components of food. Carbohydrates and fats are the energy components of the food. Proteins are bodybuilding components of the food. 

The nutrient synthesized by plants through photosynthesis is carbohydrates. Plants are autotrophs and they synthesize their own food by the process of photosynthesis. During photosynthesis, they convert carbon dioxide and water in presence of sunlight and chlorophyll to produce carbohydrates (glucose) and oxygen. 

An inorganic nutrient is essentially any compound or element that is not carbon-based, but is otherwise necessary to maintain health and optimum growth of a plant, animal, or human. Nitrogen is an inorganic nutrient that is later converted to organic forms like nitrite, nitrate or ammonia.

Proteins are major element required in the growth of the plant cells. In plants, all the 20 amino acids should be formed in the plant body because they cannot take them up fro any other source. Proteins are essential as they are the basic constituents of enzymes, cell membrane, and transport systems.

Carbohydrates, as the name suggests, are the hydrates of carbon and thus are made up of molecules of hydrogen, oxygen and carbon.

Water present in the human body supports the metabolic reactions in the body. The enzymes which act as a catalyst in these biological reaction acts efficiently in presence of water. The salts like sodium and potassium which dissolves in the water act as a transporter as it is a very good solvent. These help in the transmission of the nerve impulse. It helps to maintain a constant temperature inside the body. It also helps in cellular processes like endocytosis and exocytosis. It helps to maintain osmotic condition inside the cell.

All the constituents of food are digested but roughage or fibres are not digested, but they play a very important role in the formation and smooth elimination of bowels.