Tag: biology

Questions Related to biology

Which of the following teeth are absent in a rat?

biology digestive system of human buccal cavity digestive system - organs coordination in the process of digestion

  1. Canines and molars

  2. Incisors and molars

  3. Incisors and premolars

  4. Canines and premolars

Show answer
Correct Option: D
Explanation:

Rats have incisors and molars. Incisors are the foremost teeth in mammals. In rats, there are four, long, sharp front teeth, two on top and two on the bottom. They are specialized for gnawing. Molars are rearmost teeth in the mouth of rat used for grinding food prior to swallowing it. Rats have 12 molars, six on top and six on the bottom. Rats do not have canines (the conical, pointed teeth used for holding prey, defense) or premolars (grinding teeth behind the canines and in front of the molars).
Thus, the correct answer is option D.

Premolars are absent in

biology digestive system of human buccal cavity digestive system - organs coordination in the process of digestion

  1. Rat

  2. Elephant

  3. Both A and B

  4. None of the above

Show answer
Correct Option: D
Explanation:

Elephants have 26 teeth- 2 incisors (known as tusks), 12 deciduous premolars and 12 molars.
Rats have 8 teeth on the lower jaw and 8 on the upper jaw, a total of sixteen teeth which consists incisor, premolar and molar.
Thus, the correct answer is option D.

In Rabbit and Hare, the incisors of upper and lower jaw halves are

biology digestive system of human buccal cavity digestive system - organs coordination in the process of digestion

  1. 1 / 1

  2. 2 / 1

  3. 2 / 2

  4. 2 / 0

Show answer
Correct Option: B
Explanation:

The incisors and cheek teeth of rabbits are called aradicular hypsodont teeth. This is sometimes referred to as an elodent dentition. These teeth grow or erupt continuously. The growth or eruption is held in balance by dental abrasion from chewing a diet high in fibre. The anatomic dental formula is 2( i2/1 c0/0 m3/2 )= 16  deciduous teeth.


So, the correct option is '2/1'.

Dental formula of elephant is

biology digestive system of human buccal cavity digestive system - organs coordination in the process of digestion

  1. $ \dfrac {1,0,0,3}{0,0,0,3} $

  2. $ \dfrac {1,0,0,3}{1,0,0,3} $

  3. $ \dfrac {1,0,2,3}{1,0,1,3} $

  4. $ \dfrac {2,0,3,3}{1,0,3,3} $

Show answer
Correct Option: A
Explanation:

The dental formula of adult elephants for both species is I 1/0 C 0/0 PM 3/3 M 3/3, with a total number of 26 teeth. The two upper incisors are the tusks.


So, the correct option is 'Option A'.

Dental formula of adult human is

biology digestive system of human buccal cavity digestive system - organs coordination in the process of digestion

  1. $\frac{2122}{2122}$

  2. $\frac{2114}{2114}$

  3. $\frac{2123}{2124}$

  4. $\frac{2123}{2123}$

Show answer
Correct Option: D

Dental formula of a child is

biology digestive system of human buccal cavity digestive system - organs coordination in the process of digestion

  1. $\frac{2102}{2102}$

  2. $\frac{2120}{2120}$

  3. $\frac{2123}{2123}$

  4. $\frac{2111}{2111}$

Show answer
Correct Option: A

Dental formula shows

biology digestive system of human buccal cavity digestive system - organs coordination in the process of digestion

  1. Structure of teeth

  2. Monophyodont or diphyodont condition

  3. Number and type of teeth in both jaws

  4. Number and type of teeth in one half of both jaws

Show answer
Correct Option: D

Read the following statements and select the correct option.


Statement 1 : Dental formula gives the number of teeth in the half of each jaw.
Statement 2 : Dental formula can be expressed for insectivorous mammals as well as for the non-mammalian vertebrates. 

biology digestive system of human buccal cavity digestive system - organs coordination in the process of digestion

  1. Both statements 1 and 2 are correct.

  2. Statement 1 is correct but statement 2 is incorrect.

  3. Statement 1 is incorrect but statement 2 is correct.

  4. Both statements 1 and 2 are incorrect.

Show answer
Correct Option: B

Dental formula in human beings 

biology digestive system of human buccal cavity digestive system - organs coordination in the process of digestion

  1. $\dfrac{3223}[3223}$

  2. $\dfrac{2123}[2123}$

  3. $\dfrac{1232}[1232}$

  4. $\dfrac{2233}[2233}$

Show answer
Correct Option: B
Explanation:

The correct answer is (b).

Dental formula refers to 

biology digestive system of human buccal cavity digestive system - organs coordination in the process of digestion

  1. The minimum number of teeth in one half of one jaw

  2. The number of each type of tooth in one half of one jaw

  3. The overall geometric shape of the jaw

  4. Maximum number of teeth in the mouth

Show answer
Correct Option: A
Explanation:

In each set of teeth, incisors (I) are indicated first, canines (C) second, premolars (P) third, and finally molars (M), giving I:C:P:M which is the minimum number of teeth in one half of one jaw. 

So, 'the correct option is 'The minimum number of teeth in one half of one jaw'.