Tag: structure and functions of living organisms -ii

Questions Related to structure and functions of living organisms -ii

An adult has ............. teeth. 

biology structure and functions of living organisms -ii role of receptors in the mouth types of teeth introduction to human digestive system circulatory system and organs

  1. 20

  2. 24

  3. 28

  4. 32

Show answer
Correct Option: D
Explanation:

A normal adult mouth has 32 teeth. 

  •  Incisors: The middlemost four teeth on the upper and lower jaws.
  • Canines: The pointed teeth just outside the incisors. 
  • Premolars: Teeth between the canines and molars.
  • The molars or molar: teeth are large, flat teeth at the back of the mouth. Hence, an adult has 32 teeth.
So, the correct answer is '32'.

Cavity present in the tooth is called as

biology structure and functions of living organisms -ii role of receptors in the mouth types of teeth introduction to human digestive system circulatory system and organs

  1. Pulp cavity

  2. Nasal cavity

  3. Abdominal cavity

  4. Chest cavity

Show answer
Correct Option: A
Explanation:

Pulp cavity is the central cavity of a tooth containing the dental pulp and being made up of the root canal and the pulp chamber. Nasal cavity is present in nose, abdominal cavity in abdomen and chest cavity in chest.

Therefore, the correct answer is option A.

The study of teeth is called as

biology structure and functions of living organisms -ii role of receptors in the mouth types of teeth introduction to human digestive system circulatory system and organs

  1. Dentistry

  2. Dermatology

  3. Neurology

  4. Cardiology

Show answer
Correct Option: A
Explanation:

The study of teeth generally referred to as dentistry. It is a branch of medicine that involves the study, diagnosis, prevention, and treatment of diseases, disorders and conditions of the dentition along with oral cavity, including the oral mucosa, and the adjacent and related structures and tissues of the maxillofacial zone.

We chew the food with the

biology structure and functions of living organisms -ii role of receptors in the mouth types of teeth introduction to human digestive system circulatory system and organs

  1. Teeth

  2. Tongue

  3. Mouth

  4. None of the above

Show answer
Correct Option: A
Explanation:
Mastication or chewing is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow more efficient break down by enzymes. During the mastication process, the food is positioned by the cheek and tongue between the teeth for grinding. The muscles of mastication move the jaws to bring the teeth into intermittent contact, repeatedly occluding and opening. As chewing continues, the food is made softer and warmer, and the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food (now called a bolus) is swallowed. It enters the esophagus and via peristalsis continues on to the stomach, where the next step of digestion occurs.

Match the following.

A. Incisors 1. Grinding teeth
B. Canines 2. Cracking teeth
C. Premolars 3. Cutting teeth
D. Molars 4. Tearing teeth
biology structure and functions of living organisms -ii role of receptors in the mouth types of teeth introduction to human digestive system circulatory system and organs

  1. A- 2, B- 4, C- 1, D- 3

  2. A- 2, B-1 , C- 4, D- 3

  3. A- 3, B- 2, C- 4, D- 1

  4. A- 3, B- 4, C- 2, D- 1

Show answer
Correct Option: D
Explanation:

Incisor is a narrow-edged tooth at the front of the mouth, adapted for cutting. In humans there are four incisors in each jaw. On each side of the incisors, at the corners of the mouth, are the canines. These teeth have one cusp, or pointed edge, and are used for holding or grasping food, and are very strong, stable teeth. Behind the canines are the premolars, which are designed for holding food like the canines because they have cusps, but they also function to crush food. Sometimes these teeth are referred to as bicuspids, meaning two cusps, but this is not always accurate because some premolars may have three cusps. Therefore, the term premolar is preferred. The teeth farthest back in the mouth are the molars. These teeth have broad chewing surfaces with four or five cusps, and are designed for grinding food. Thus, option D is correct.

Calcium and ............. gives rigidity to bones and teeth 

evs structure and functions of living organisms -ii role of receptors in the mouth types of teeth introduction to human digestive system circulatory system and organs

  1. Oxalate

  2. Pectate

  3. Carbonate

  4. Phosphate

  5. Sulphate

Show answer
Correct Option: D
Explanation:
Phosphorus is found within the skeleton and teeth, where it is compounded with calcium to form calcium phosphate.  It is a primarily component of hydroxyapatite crystals in bones and teeth, and help in rigidity to the softer portions. 
So the correct answer is D.

The number of teeth that grow twice in human life is 

evs structure and functions of living organisms -ii role of receptors in the mouth types of teeth introduction to human digestive system circulatory system and organs

  1. 4

  2. 12

  3. 20

  4. 28

Show answer
Correct Option: C
Explanation:

20 milk teeth of a child get replaced in adulthood by 20 permanent teeth. But the rest 12 can never be replaced if broken, these 12 teeth grow only once in a man’s life.
So, the correct option is '20'.

The primary dentition in human differs from permanent dentition in not having one of the following type of teeth

evs structure and functions of living organisms -ii role of receptors in the mouth types of teeth introduction to human digestive system circulatory system and organs

  1. Canine

  2. Premolars

  3. Molars

  4. Incisors

Show answer
Correct Option: B
Explanation:

There are 20 primary teeth which are lost as the child grows and is replaced by 32 permanent teeth. Primary dentition comprises of 8 incisors, 4 canines and 8 molars while permanent teeth comprises of 8 premolars in addition to newly formed 8 incisors, 4 canines and 12 molars. Premolars take the place of molars present in the primary dentition.

Consider the following statements each with two blanks.
(A) Seminiferous tubules produce (i) while Leydig's cells produce (ii).
(B) In females, urethra is small and conducts (iii) while in males it conducts urine and (iv).
(C) The process Of formation of spermatozoa from spermatogonia is called (v) and the process of maturation of spermatids into spermatozoa is called (vi).
Which one of the following options, gives the correct fill ups for the respective blank numbers from (i) to (vi) in the statements?

biology structure and functions of living organisms -ii role of receptors in the mouth types of teeth circulatory system and organs

  1. (i)-spermatozoa, (ii)-testosterone,

    (v)-spermatogenesis, (vi)-spermiogenesis

  2. (i)-testosterone, (ii)-spermatozoa, (iii)-urine, (iv)-semen

  3. (i)-estrogen, (ii)-testosterone, (v)-spermiogenesis, (vi)-spermatogenesis

  4. (iii)-urine, (iv)-semen, (v)-spermiogenesis, (vi)-spermatogenesis

Show answer
Correct Option: A
Explanation:

The seminiferous tubules are the location of the production of spermatozoa or sperms in the testicular lobule. The Leydig cells (interstitial cells) outside the seminiferous tubule synthesize and secrete testicular hormones called androgens or testosterone. Spermatogenesis is the process of immature male germ cells (spermatogonia) develop into mature sperms or spermatozoa. After this process, the conversion of the four equal haploid spermatids into spermatozoa (sperms) is called spermiogenesis. 

So, the correct option is '(i)-spermatozoa, (ii)-testosterone, (v)-spermatogenesis, (vi)-spermiogenesis'.

In frogs, body proportions do not change with their growth. A frog  that is twice as long as another will be  heavier by approximately ?

biology structure and functions of living organisms -ii role of receptors in the mouth types of teeth circulatory system and organs

  1. Two-fold

  2. Six-fold

  3. Four-fold

  4. Eight-fold

Show answer
Correct Option: A
Explanation:

In frogs, body proportions do not change with their growth. This means that the weight and height of a frog increase and decrease proportionately. If one of these parameters increase, so does the other, and by the same proportion, and vice-versa. Hence, if a frog is twice as long as another, it will be approximately two times heavier also.

So, the correct answer is 'Two-fold'.