CBSE Questions for Class 7 Biology Nutrition In Animals Quiz 2 - MCQExams.com

• There are five steps in holozoic (organic food is taken from outside) nutrition - ingestion, digestion, absorption, assimilation, and egestion. 
• Ingestion is the process the food is taken inside through the mouth and broken down by teeth and digestion begins in the mouth by saliva.
• Digestion is the process in which food is digested by few enzymes and is used by the cells for producing energy.
• Absorption is the process in which cells use the energy from the digested food and helps in building tissues in the body.
• Assimilation is the process in which digested food moves into the cells of the body.
• Egestion is the process in which undigested food is removed out from the body through excretion.

• The animals which partially digest food have a four-chambered stomach and the process of digestion is as follows: The food is chewed and swallowed quickly and passed into the first stomach called Rumen.
•  Then the microorganisms help in breaking down the food and this partially digested food is called cud. Hence, the rumen is the stomach part in which herbivores secretes the grass which is swallowed quickly.

$$\textbf{Correct answer: B}$$  

$$\textbf{Option (A):}$$  

$$\bullet$$ In the above diagram, the teeth marked as A represent the incisors of the upper jaw. There are four incisors in each jaw. 

$$\bullet$$ This is responsible for cutting the food.

$$\textbf{Option (B):}$$  

$$\bullet$$ The teeth marked as B in the diagram represent the canines of the upper jaw. There are two canines in each jaw. 

$$\bullet$$ Canines are responsible for tearing the food. 

$$\textbf{Option (C):}$$  

$$\bullet$$ The teeth marked as C in the diagram represent the premolars of the upper jaw. There are four premolars in each jaw. 

$$\bullet$$ This is responsible for chewing and grinding the food.

$$\textbf{Option (D):}$$  

$$\bullet$$ The teeth marked as D represent the molars. There are 6 molars in each jaw. 

$$\bullet$$ The flat surface of the crown facilitates grinding, mastication and chewing of food using the molars.

Hence, the correct answer is option (B).

• Ingestion - The process of taking food into the body is called ingestion.
• Digestion - It involves the break down of nutrients such as proteins into amino acids, carbohydrates into starch, and fats into fatty acids and glycerol.
• Absorption - It involves the absorption of nutrients from the food to the blood.
• Assimilation - It involves the process of transporting nutrients and water to all parts of the body by blood.
• Egestion - It involves the disposal of undigested food from the body. Hence, various steps of human nutrition are in the order - Ingestion, digestion, absorption, assimilation and egestion.

$$\textbf{Correct answer: D}$$  

$$\textbf{Option (D):}$$  

1. Incisors                                    c. Cutting teeth

$$\bullet$$ The incisors act as the cutting teeth because they are responsible for cutting the food. 

$$\bullet$$ While eating, incisors cut the food into fragments. 

$$\bullet$$ Canines are called tearing teeth because they help with the steering of muscles. 

$$\bullet$$ Canines are important for flesh-eating animals. 

$$\bullet$$ Premolars are called cracking teeth as it cracks the food into small fragments. 

$$\bullet$$ The molars are called grinding teeth because it helps in grinding the food and mastication. 

$$\bullet$$ Therefore the correct sequence of teeth with their specific function will be: 1 - c, 2 - d, 3 - b, 4 - a

Hence, the correct answer is option (D).

$$\textbf{Correct answer: D}$$  

$$\textbf{Option (D):}$$  

$$\bullet$$ The number of teeth in an adult human is 32.

$$\bullet$$ There are different types of teeth including 8 incisors, 4 canines, 8 premolars and 12 molars. All the types of teeth are present in the two jaws.

Hence, the correct answer is option (D).

• The animals which partially digest food have a four-chambered stomach and the process of digestion is as follows: 
• The food is chewed and swallowed quickly and passed into the first stomach called Rumen. So, the animals are referred to as ruminants. 
• Then the microorganisms help in breaking down the food and this partially digested food is called cud. 
• Hence, Partially digested food in ruminants is cud.