Fats are broken down into free fatty acids (FFA) and triglycerides which can produce ATP through chemical reactions.

Calories are needed to provide energy so the body functions properly. The number of calories in a food depends on the amount of energy the food provides. The number of calories a person needs depends on age, height, weight, gender, and activity level. People who consume more calories than they burn off in normal daily activity or during exercise are more likely to be overweight.

Saturated fats are simply fat molecules that have no double bonds between carbon molecules because they are saturated with hydrogen molecules. These are typically solid at room temperature and are found in animals.

Vit B & C are water-soluble. Vit K is fat-soluble required for the formation of many clotting factor-like prothrombin. Vit A is also fat-soluble.

Carbohydrates are the primary fuel used in cellular metabolism. Excess carbohydrates are stored as glycogen and fats. The fats are a very concentrated source of energy. One gram of fat provides 8.8 kcal of energy as against 4.2 kcal provided by one gram of carbohydrate.

Carotenoids are organic pigments that are found in the chloroplasts and chromoplasts of plants and some other photosynthetic organisms, including some bacteria and some fungi. Carotenoids can be produced from fats and other basic organic metabolic building blocks by all these organisms. All carotenoids are tetraterpenoids, meaning that they are produced from 8 isoprene molecules and contain 40 carbon atoms.

Carbohydrates are the preferred fuel for cellular respiration. Excess carbohydrates are stored as glycogen in muscles and liver. Glycogen storage is for short duration only. Glycogen reserves meet energy demand between meals and during intense physical exercises. Long term storage of carbohydrates occurs as fats. After storing glycogen, still extra carbohydrates available are converted to fats for long term storage in the body.

The fats contain more energy per gram than carbohydrates and as a result of this, the body tends to use fat to store energy over long periods of time and uses carbohydrates to store energy short-term.
Therefore, the correct answer is option B.

We need energy for doing work. Energy is provided by carbohydrates and fats. Carbohydrates and fats on oxidation liberate energy. As compared to fats, carbohydrates get easily oxidized and converted into glucose and provide energy. One gram of carbohydrate yields about 17 kilo-joule of energy, whereas one gram of fat produces 37 kilo-joule of energy. This is the reason why carbohydrates and fats are called as energy food.

Slightly less than half of the cholesterol in the body derives from biosynthesis de novo. Biosynthesis in the liver accounts for approximately 10% and in the intestines approximately 15%, of the amount produced each day. The cholesterol biosynthesis pathway involves enzymes that are in the cytoplasm, microsomes (ER), and peroxisomes. Synthesis of cholesterol, like that of most biological lipids, begins from the two-carbon acetate group of acetyl-CoA. Cholesterol synthesis does not occurs in pancreas, spleen and Brunner's gland. 

Oxidation refers to the direct breakdown of nutrients for energy. Fats or lipids have the highest energy content of 9 kcal/gm while proteins and carbohydrates have 4 kcal/gm.
Therefore, the correct answer is option D.

Products of $\beta$-oxidation are as follows-
a) Acetyl ${C} _{0}A$
b) $FAD{H} _{2}$
c) $NAD{H} _{2}$

Although, the main source of energy for our bodies is carbohydrates, fat is used as a source of backup energy in cases when carbohydrates are not available. This is a concentrated energy source but it is important to remember that each gram of fat has nine calories (over double the calories from protein and carbohydrates) so you should avoid having more than 20 to 35% of your daily calories from fat. In a 1,800 calorie diet, you should only consume 40-70 grams of fat.

Non-essential fatty acids are those fatty acids that the body can synthesize on its own. Essential fatty acids are those fatty acids that are required by the body but it cannot synthesize. There are two essential fatty acids, linoleic and alpha-linolenic acid. These must be obtained from food. 

Because riboflavin is an orange-yellow compound, so cow's milk appears slightly yellowish.

The body temperature in cold blooded varies with that of the environment as there is no fat deposition. On the other hand, cold blooded animals use fat during hibernation to carry out their metabolic processes.

Unsaturated fats are liquid at room temperature as they have double bonds. Saturated fatty acids have single bond and are solid at room temperature. Polyunstaurated fats are good for health as they boost up the good cholestrol level. As they are liquid so they do not choke the blood vessels and they are easily metabolized. Polyunsaturated fats include omega-3 and omega-6 fats. These are essential fatty acids that the body needs for brain function and cell growth.

Obesity is an abnormal increase in the proportion of fat cells mainly in the viscera and subcutaneous tissues of the body.

The excess carbohydrates and proteins are stored in the body as fats. It gets converted into energy during excessive physical work. Essential fatty acids are those fatty acids which play an important role in the biological process and they can be metabolized easily. These acts as a fuel rather getting deposited as fat in the body. The human body cannot synthesize essential fatty acids. Unsaturated fats are liquid at room temperature as they have double bonds. The essential fatty acids are unsaturated as they have double bonds. Saturated fatty acids have the single bond and are solid at room temperature.

In human and most other mammals, acetyl Co-A formed in the liver during oxidation of fatty acids can enter the citric acid cycle or can be converted to the "Ketone bodies" (e.g., Acetone, Acetoacetate and D - $\beta $ hydroxy butyrate) for export to other tissue.

Fat is an essential part of our diet and is important for good health.

fat is the major storage form of energy in the body. These are found in plant foods and fish. Fats help in the absorption of fat-soluble vitamins A, D, E, and K. 

So, the correct option is ‘Fats yield the double amount of energy yielded by glucose on oxidative breakdown’.

Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them. Two essential fatty acids, linolenic and linoleic acid, cannot be synthesized in the body and must be obtained from food. These basic fats, found in plant foods, are used to build specialized fats called omega-3 and omega-6 fatty acids.

Fatty acids are long, straight chain carboxylic acids. A fat molecule is formed when three fatty acids molecules combine with one glycerol molecule to yield a triglyceride (another name for fat) along with three water molecules. Fats are not easily digested and are transported and stored as triglycerides.

Dioscorea spp, commonly known as Yams belong to family Dioscoreaceae. The true Yams, belonging to the genus Dioscorea are grown throughout the wetter tropics for their stem tubers. They are important sources of food for millions of people in the tropics, especially in the south western Nigeria where they are a staple food. Dioscorea is a large genus with about 600 tropical or subtropical species. Yams constitute a cheap source of carbohydrate foods and are nutritionally better than cassava because of a higher proportion of proteins. They also contain more of vitamin C.
In recent years, wild species have been much used for the extraction of steroidal sapogenins which can be converted into cortisone, into the testosterone (male hormone) and the oestrogens as well as progesterones (female hormones). Three wild species particularly D. composita, D floribunda, D. mexicana have been used as a source material for the manufacture of oral contraceptives. In this way this genus has contributed significantly towards controlling the world population.

Gaucher disease is a rare genetic disorder characterized by the deposition of glucocerebroside in cells of the macrophage-monocyte system. The disorder results from the deficiency of the enzyme glucocerebrosidase.

The term Lipid was coined by Bloor.

Carbohydrates which includes  sugars and starches, contain 4 calories per gram, and are considered one of the main sources of energy for the human body. Fats on the other hand give 9 calories per gram,which is approximately 2.5 times more energy than carbohydrates. Moreover, fats contain more carbon-carbon and carbon-hydrogen bonds than carbohydrates or proteins and are therefore richer in energy. 

Meats, dairy products, seeds, nuts and oils contain dietary fat which needs to be broken down to be absorbed by the system. While the bile contains bile salts that emulsifies and pancreatic lipase acts to break lipids, to be absorbed in the blood stream this goes through further breakdown process in the small intestine where lacteals found in the villi of the intestinal wall help the lipids to pass through the  lymphatic system.

Lipids are fat-like molecule that cannot dissolve in water. When these reach the small intestine, the enzymes present there responsible for fat digestion acts on it. The pancreatic lipase breaks lipids down, resulting in free fatty acids and monoglycerides. Further, these are resynthesized into triglycerides which enter the lymphatic capillaries and lacteals present as the finger-like projections of the villi these acts on the lipids so as to be absorbed before they enter the bloodstream. 

Soybean seeds have 40% protein content and 20% of oil which accounts for 60% weight of dry soybeans. The remainder 35% is carbohydrate. With the highest protein content among plant products, 100g serving of soybean consists of 17g protein, 1g of saturated fat, 10g of carbohydrate and 6g of fibre. 

A gram of butter provides more energy than a gram of sugar because butter has more carbon-hydrogen bonds.

Fat contains 9 kcal per gram, whereas carbohydrates and protein only contain 4 kcal per gram.