CBSE Questions for Class 7 Biology Nutrition In Animals Quiz 5 - MCQExams.com

• Function- Its main function is to bite the food. 
  

• These are the sharpest teeth.
• Function-  It helps to tear the food.
  

• We have two premolars each on the upper and the lower jaw.
  
• Function- they help in chewing and grinding food. 

• Function-  they also help in chewing and grinding food.
• The dentition in humans is 2123- incisors-2, canines-1, premolars- 2, molars- 3.
• So, the correct answer is 'A - molar, B - premolar, C - canine, D-incisor'.

• There are four types of teeths- incisor, canine, premolar, and molar. The molars are the largest teeth of all. 
• The premolars present next to molars. Molars are 12 in number, whereas premolars are 8 in number. 
• The function of these types of teeth is similar (crushing and grinding of food) but they are different in structure.

• Residual bodies are cytoplasmic vacuole containing the leftover products of digestion after fusion with the contents of a lysosome.
• Residual bodies are either secreted by the cell via exocytosis (this generally only occurs in macrophages), or they become lipofuscin granules that remain in the cytosol indefinitely.
• They are not involved in autolysis like that of lysosomes. 

$$\textbf{Option (D):}$$ 

$$\bullet$$ The total number of milk teeth present in infants is 20.

$$\bullet$$ Out of them, there are 8 incisors, 4 canines and 8 molars. There are no premolars among the milk teeth.

$$\bullet$$ One canine is present on the two sides of every jaw. This means in every jaw there are two canines present just beside the incisors.

The total number of canines in the infant dental set will be $$4$$.

Hence, the correct answer is option (D).

• Human teeth have two sets of teeth during their life i.e, one temporary set of milk and one permanent set. 
• The temporary teeth or milk teeth are the first set of teeth that are replaced by permanent teeth upon the age of 12 years. 
• So the first set of teeth are called temporary or milk teeth.

• A cow has sac-like rumen which has bacteria that synthesize cellulase enzyme. This enzyme helps in the digestion of the cellulose present in grasses.