CBSE Questions for Class 7 Biology Nutrition In Animals Quiz 1 - MCQExams.com

• For humans, components of food include carbohydrates, proteins, good fats and essential sugars. 
• Water is also one of the essential components of the diet.

• Bees and humming-birds suck the nectar of plants.
  
• Infants of human and many other animals feed on mothers milk.
• Snakes like the python swallow the animals they prey upon.
  
• Some aquatic animals filter tiny food particles floating nearby and feed upon them.

• Some microbes like methanobacteria live a symbiotic relationship with ruminants and are found in their rumen.
  
• These methanobacteria help the ruminants in the digestion of cellulose and hemicellulose in food.

• The digestive glands (salivary glands, pancreas, liver, and gallbladder) produce or store secretions that the body carries to the digestive tract in ducts and breaks down chemically. 
• The teeth help in mechanical digestion by masticating (chewing) food.
• The whole process starts in the oral cavity, where the saliva from the salivary glands mixes with the food and starts to begin the breakdown of food. This semi-digested food then travels down to the small intestine, where secretions from the liver, gallbladder, and pancreas further act on the food particles. Hence, Teeth are not only part of the digestive system that physically breaks down food.
• So, the correct answer is 'False'.

• In the permanent dentition of a human, there are normally 28 teeth before his/her twenties that include 8 incisors, 4 canines, 8 premolars, and 8 molars.
• Wisdom teeth (4 in number) are the third and final set of molars that most people get in their late teens or early twenties. 
  
• After which the number of molars will be 12 while the total number of teeth will be 32.

$$\textbf{Correct answer: A}$$  

$$\textbf{Option (A):}$$  

$$\bullet$$ The intake of food through the mouth is called ingestion. After ingesting the food,  the enzyme action starts on it.

$$\textbf{Option (B):}$$  

$$\bullet$$ Egestion is the process of removal of undigested food materials through the anus in the form of faeces.

$$\textbf{Option (C):}$$  

$$\bullet$$ Digestion is the process of active conversion of complex food molecules in their simple forms with the action of enzymes. 

$$\bullet$$ There are multiple digestive glands that are present throughout the alimentary canal. Enzyme secretion from these glands helps in the digestion of nutrients which makes it suitable for absorption.

$$\textbf{Option (D):}$$  

$$\bullet$$ Food required to maintain good health with a balanced diet is called nutrition.

$$\bullet$$ The presence of proper nutrients in the diet is important to maintain the best state of health. 

Hence, the correct answer is option (A).