Test: Nutrition in Animals - UPSC MCQ

Salivary glands in our mouth produce saliva. Saliva helps in breaking down food while chewing and swallowing. It also contains enzymes that start the digestion process.

The process of intake of food inside the body is known as Ingestion. It is a vital step in the process of animal nutrition. When animals eat or drink something, they are ingesting it.

Ingestion involves taking food into the mouth and swallowing it. The mouth is the starting point of the digestive system, where the process of breaking down food begins. Animals have different ways of ingesting food depending on their body structure and eating habits.

Production of Bile in the Liver

- The liver is the primary organ responsible for the production of bile in the human body.
- Bile is a yellow-green fluid that aids in the digestion and absorption of fats in the small intestine.
- Hepatocytes, the main functional cells of the liver, synthesize bile by extracting waste products, cholesterol, and other substances from the blood.
- Bile is then stored and concentrated in the gallbladder before being released into the small intestine to help with the digestion of fats.

• Humans have two sets of teeth.
• The first set is called milk teeth, which we get when we are babies.
• These teeth fall off when we are around six to eight years old.
• The second set that grows in place of the milk teeth are called permanent teeth.
• These teeth can last for a long time or fall off when we get old or if we have some problems with our teeth.
• So, remember, we have milk teeth first, and then we get our permanent teeth.

The stomach receives food from the food pipe and opens into the small intestine at the other end for further digestion and absorption of nutrients.

The Correct Option is d: Absorption

The process of digested food passing into the blood vessels in the wall of the intestine is called Absorption.
During digestion, food is broken down into smaller molecules that can be absorbed and used by the body for energy and other functions. After digestion takes place in the stomach and small intestine, the resulting nutrients, such as glucose, amino acids, and fatty acids, need to be transported into the bloodstream so that they can be distributed to various cells and tissues in the body.

'Hydrochloric acid' (HCL) is an acid that is secreted in the stomach. It helps to kill the harmful bacteria that may enter with food.

Saliva helps in breaking down the starch in food into sugars. This makes it easier for our bodies to digest the food we eat. So, saliva plays an important role in making food easier for our bodies to use for energy.

The process of cud returning to the mouth and being chewed is called Rumination.

Rumination is a special way of digesting food that happens in animals like cows, sheep, and goats. These animals have a special part in their stomach called the rumen that helps them get the most out of the nutrients in plants. When they eat, the food goes into the rumen where it gets broken down by tiny organisms and turns into a soft lump called cud.

Oesophagus is the part of the body which is responsible for carrying food from the mouth to the stomach. It is also commonly known as Food Pipe.

• Villi in the intestine help to absorb the food that has been digested.
• They are like tiny fingers that take in the good parts of the food and send them to different parts of the body to help us grow and stay healthy.

The finger-like projections are called “pseudopodia“. They not only help in engulfing food molecules but also help the organism in movement.

The correct sequence of the main steps of nutrition in humans is:

- Ingestion: Intake of food
- Digestion: Breakdown of food into smaller molecules
- Absorption: Passage of digested food molecules into the bloodstream
- Assimilation: Utilization of absorbed nutrients by cells
- Egestion: Elimination of undigested waste

This order ensures that nutrients are extracted from food, absorbed, utilized by the body, and waste is removed efficiently.

1. Liver:

   • Size: The liver is the largest gland in the human body, weighing about 1.5 kg (3.3 lbs) in adults. It is located in the upper right part of the abdomen.

2. Pancreas:

   • Size: The pancreas is smaller compared to the liver. It weighs around 70-100 grams.
   • Functions: It has both endocrine (insulin and glucagon production) and exocrine (digestive enzyme secretion) functions, but it is not the largest gland.

3. Thyroid:

   • Size: The thyroid gland is relatively small, located in the neck. It weighs about 20-30 grams.
   • Functions: Produces hormones like thyroxine (T4) and triiodothyronine (T3) that regulate metabolism.

4. Adrenal:

   • Size: The adrenal glands are small, triangular-shaped glands located on top of each kidney.
   • Functions: They produce hormones such as adrenaline, cortisol, and aldosterone, but are smaller in size compared to the liver.

The liver’s size, combined with its extensive role in metabolic and regulatory functions, makes it the largest gland in the human body.

Gastric juice is a variable mixture of water, hydrochloric acid, electrolytes (sodium, potassium, calcium, phosphate, sulfate, and bicarbonate), and organic substances (mucus, pepsins, and protein). This juice is highly acidic because of its hydrochloric acid content, and it is rich in enzymes.