Tag: structure and functions of living organisms -ii

Questions Related to structure and functions of living organisms -ii

Eye teeth are

  1. Upper incisors

  2. Lower incisors

  3. Lower canines

  4. Upper canines


Correct Option: D
Explanation:

Canines in the upper arch are also often called “eye teeth,” which, when you come to think of it, is kind of a weird name for them. But the most common explanation is actually pretty simple: these teeth lie directly below the eye sockets.


So, the correct option is 'Upper canines'.

Which one of the following pairs of types of teeth perform one common function as stated against it?

  1. Incisors, canines - Holding

  2. Canines, premolars - Biting

  3. Premolars, molars - Grinding

  4. Molars, incisors - Tearing


Correct Option: A

State whether the following statements are true or false.
When Van Leeuwenhoek examined scrapings of his teeth under a microscope after drinking hot coffee, he saw living germs in them.

  1. True

  2. False


Correct Option: B
Explanation:

Van Leeuwenhoek examined single-celled organelles and called them as animalcules when he was working with the lenses.

So, the correct option is 'False'.

Choose the correct answers from the alternatives given.
In mammals, mastication of the food is done by

  1. molars

  2. premolars

  3. incisors

  4. canines


Correct Option: A
Explanation:

  • The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. 
  • They are used primarily to grind food during chewing.
  • Molars show a great deal of diversity in size and shape across mammal groups. Hence, in mammals, mastication of the food is done by molars.
So, the correct answer is 'molars'.

Carnassial teeth, which are pointed molars, would most likely be part of the dentition of a

  1. human

  2. cow

  3. lion

  4. hawk


Correct Option: C
Explanation:

Carnassial teeth. which are pointed molars, would most likely be part of the dentition of a carnivore

(A)Human is an omnivore
(B)A cow is a herbivore
(C)Lion is a carnivore
(D)Hawk is a herbivore
So, the correct answer is 'Lion'

Wisdom tooth is the

  1. first molar tooth

  2. second molar tooth

  3. third molar tooth

  4. fourth molar tooth


Correct Option: C
Explanation:

A wisdom tooth or third molar is one of the three molars per quadrant of the human dentition. It is the most posterior of the three. Wisdom teeth generally erupt between the ages of 17 and 25

So, the correct answer is 'third molar tooth'

Teeth are the only part of the digestive system that physically breaks down food.

  1. True

  2. False


Correct Option: B
Explanation:

  • 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'.

Upper molars in human dentition have

  1. Four roots

  2. Three roots

  3. Two roots

  4. Single root


Correct Option: B
Explanation:

Humans have four types of teeth, namely incisors, canines, premolars and molars. Each type of teeth has specific structure and function. The roots of teeth are embedded in the upper jaw and the lower jaw. Humans have 32 teeth, 8 incisors, 4 canines, 8 premolars and 12 molars. Canines and premolars have one root. Upper first premolars and lower molars have two roots. Upper molars have three roots.

Thus, the correct answer is 'Three roots.'

Incisor teeth in mammals are primarily for ________________.

  1. Weapons or for killing prey

  2. Grinding and chewing food

  3. Cutting and slicing food

  4. All of these


Correct Option: C
Explanation:

Incisors are the front four teeth which are used for cutting/biting and slicing the food, canines are the pointed teeth which helps in tearing the food whereas molars are the teeth which are used for Grinding and chewing of food particles. 

So, the correct option is 'Cutting and slicing food'