Class 7 science -Chapter 2 – Nutrition in Animals – Definition and Explanation of Important Keywords

Absorption-

• Definition- Absorption is the process by which digested food materials are taken up into the bloodstream from the walls of the small intestine for distribution to various body organs.
• Explanation- After the process of digestion, where food is broken down into simpler substances, the nutrients are absorbed through the walls of the small intestine into the bloodstream. This allows the body to use these nutrients for various bodily functions.

Amino Acid-

• Definition- Amino acids are the building blocks of proteins. They are simple organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulphur.
• Explanation- Amino acids are essential for the body to build and repair tissues, produce enzymes and hormones, and perform various other functions. They are obtained from the digestion of proteins in the diet.

Also Check – Rapid Revision – Class 7 Science -Chapter 2 – Nutrition in Animals – Complete Notes

Amoeba-

• Definition- Amoeba is a microscopic, single-celled organism found in pond water. It exhibits pseudopodia, finger-like projections used for movement and capturing food.
• Explanation- – Amoeba is a simple organism that captures and digests microscopic organisms by engulfing them in food vacuoles. It relies on this process for nourishment and growth.

Assimilation-

• Definition- Assimilation is the process by which absorbed nutrients are used by the body to build complex substances required for growth, maintenance, and multiplication.
• Explanation- After nutrients are absorbed into the bloodstream, they are transported to various body organs where they are utilised to create proteins, carbohydrates, and fats needed for bodily functions and growth.

Also Check – Class 7- Chapter 2 – Nutrition in Animals – 4 Worksheets Solved and Unsolved

Bile-

• Definition- Bile is a digestive fluid produced by the liver and stored in the gallbladder. It plays a crucial role in the digestion and emulsification of fats.
• Explanation- Bile is released into the small intestine to help break down and emulsify fats, making them easier for digestive enzymes to work on. This process aids in the absorption of fats.

Buccal Cavity-

• Definition- The buccal cavity is the cavity within the mouth where food is ingested. It includes the mouth and the structures within it.
• Explanation- The buccal cavity is the initial site where food enters the digestive system. It is where mechanical digestion begins with the action of chewing and mixing food with saliva.

Canine-

• Definition- Canines are specific types of teeth in mammals, including humans, that are typically pointed and used for tearing and piercing food.
• Explanation- Canine teeth play a role in the initial breakdown of food by tearing and piercing it during chewing. They are part of the overall dental structure.

Cellulose-

• Definition- Cellulose is a complex carbohydrate found in the cell walls of plants. It is a type of fibre that cannot be digested by many animals, including humans.
• Explanation- Cellulose is a vital component of plant cell walls. While it provides structural support for plants, it is not digested by most animals due to the lack of enzymes required to break it down.

Digestion-

• Definition- Digestion is the process of breaking down complex food substances into simpler forms through mechanical and chemical processes, making them absorbable by the body.
• Explanation- Digestion is essential for converting food into nutrients that can be absorbed and used by the body for energy, growth, and maintenance of bodily functions.

Egestion-

• Definition- Egestion is the process of eliminating undigested waste material, such as faeces, from the body.
• Explanation- After digestion and absorption of nutrients, the remaining indigestible material is expelled from the body through the rectum and anus in the form of faeces.

Fatty Acid-

• Definition- Fatty acids are organic molecules that serve as the building blocks of fats. They are essential for various physiological functions in the body.
• Explanation- Fatty acids are important components of dietary fats and are crucial for the synthesis of cell membranes, hormones, and energy storage.

Food Vacuole-

• Definition- A food vacuole is a membrane-bound structure within cells, such as amoebas, used to enclose and digest food particles.
• Explanation- In organisms like amoebas, food vacuoles form when food particles are engulfed. Digestive juices are then secreted into these vacuoles to break down the food into simpler substances.

Gallbladder-

• Definition- The gallbladder is a small sac-like organ located beneath the liver. It stores bile produced by the liver and releases it into the small intestine to aid in fat digestion.
• Explanation- The gallbladder plays a role in the digestion of fats by storing and releasing bile as needed to emulsify fats in the small intestine.

Glycerol-

• Definition- Glycerol is a simple alcohol compound that is a component of fats (triglycerides). It can be converted into glucose for energy.
• Explanation- Glycerol is a product of fat digestion and can be converted into glucose through a process called gluconeogenesis, providing an energy source for the body.

Incisor-

• Definition- Incisors are a type of tooth found in mammals, including humans. They are typically flat and used for cutting and biting food.
• Explanation- Incisors are essential for the initial breakdown of food by cutting and biting. They are located at the front of the mouth and play a role in food preparation for digestion.

Ingestion-

• Definition- Ingestion is the process of taking food into the mouth for digestion.
• Explanation- It is the initial step in the digestive process where food is introduced into the buccal cavity (mouth) to begin the breakdown process.

Liver-

• Definition- The liver is a reddish-brown gland located in the upper part of the abdomen on the right side. It is the largest gland in the body.
• Explanation- The liver serves various functions, including the production of bile, which aids in fat digestion. It also plays a crucial role in detoxification and metabolism.

Milk Teeth-

• Definition- Milk teeth are the first set of teeth that grow during infancy and eventually fall off. They are temporary and are replaced by permanent teeth.
• Explanation- Milk teeth are important for initial chewing and breaking down of food in children. As children grow, these teeth naturally fall out to make way for permanent teeth.

Molar-

• Definition- Molars are large, flat teeth located at the back of the mouth used for grinding and crushing food.
• Explanation- Molars are essential for efficient chewing and grinding of food to aid in digestion. They are part of the dental structure.

Permanent Teeth-

• Definition- Permanent teeth are the second set of teeth that replace milk teeth and typically last throughout a person’s life.
• Explanation- Permanent teeth are well-adapted for the long-term chewing and breakdown of food. They include incisors, canines, premolars, and molars.

Oesophagus-

• Definition- The oesophagus (or oesophagus) is the muscular tube that connects the buccal cavity (mouth) to the stomach and is responsible for the transport of food from the mouth to the stomach.
• Explanation- The oesophagus facilitates the passage of food from the mouth to the stomach through rhythmic muscle contractions, known as peristalsis.

Pancreas-

• Definition- The pancreas is a large cream-coloured gland located just below the stomach.
• Explanation- The pancreas secretes pancreatic juice, which contains enzymes responsible for the digestion of carbohydrates, fats, and proteins in the small intestine.

Premolar-

• Definition- Premolars are teeth located between molars and canines, used for crushing and tearing food.
• Explanation- Premolars assist in food preparation by further breaking down and chewing food before it reaches the molars for grinding.

Pseudopodia-

• Definition- Pseudopodia are finger-like projections that can be extended by cells like amoebas for movement and capturing food.
• Explanation- Amoebas use pseudopodia for locomotion and engulfing food particles, facilitating their movement and nutrition.

Rumen-

• Definition- The rumen is a part of the stomach in ruminant animals like cows and deer, where food is partially digested and stored.
• Explanation- In ruminants, the rumen serves as a fermentation chamber where cellulose-rich food is broken down by bacteria before being regurgitated and further chewed during rumination.

Also Check – Digestion in Grass Eating Animals

Ruminant-

• Definition- Ruminants are animals like cattle and deer that have a specialised stomach with compartments for the digestion of cellulose-rich food.
• Explanation- Ruminants possess a unique digestive system that allows them to efficiently digest and extract nutrients from fibrous plant material.

Rumination-

• Definition- Rumination is the process by which certain animals, known as ruminants, regurgitate and rechew their food, aiding in further digestion.
• Explanation- Rumination allows ruminants to break down tough plant material more effectively by repeatedly chewing their cud (partially digested food) and promoting better digestion.

Salivary Glands-

• Definition- Salivary glands are glands located in the mouth that secrete saliva.
• Explanation- Saliva contains enzymes that initiate the digestion of carbohydrates in the mouth and help in the initial breakdown of food.

Villi-

• Definition- Villi are tiny, finger-like projections on the inner walls of the small intestine that increase the surface area for absorption of digested food.
• Explanation- Villi plays a crucial role in the absorption of nutrients from the small intestine into the bloodstream, allowing for efficient nutrient uptake.

Saliva-

• Definition- Saliva is a watery fluid produced by the salivary glands in the mouth. It contains enzymes that begin the digestion of carbohydrates.
• Explanation- Saliva moistens food, making it easier to swallow, and contains enzymes like amylase that initiate the breakdown of starches into simpler sugars during the initial stages of digestion.

Chapter 2 – NUTRITION IN ANIMALS -Class 7 – Complete Notes

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