Tag: coordination in life processes

Questions Related to coordination in life processes

Single-layer of flattened cells with boundaries is observed in all of the following except

  1. Blood vessels

  2. Lining of oesophagus

  3. Air sacs of lungs

  4. Both (A) and (B)


Correct Option: B
Explanation:

Single layered of flattened cells with irregular boundaries constitute the squamous epithelium which is found in walls of blood vessels and air sacs of lungs. The epithelium that lines the oesophagus is stratified epithelium.

So, the correct option is 'lining of the oesophagus'.

Middle part of oesophagus in human being is

  1. Voluntary only

  2. Involuntary only

  3. Both voluntary and involuntary

  4. Skeletal muscles


Correct Option: C
Explanation:
  • The oesophagus is a hollow, muscular tube that connects the mouth to the stomach and also carries food and liquids to the stomach from the mouth.
  • It is usually around 9 to 10 inches in adults which begins at the pharynx and passes behind the trachea or windpipe.
  • The upper part of the oesophagus is made up of striated or voluntary muscles.
  • The middle part is composed of both striated and smooth or involuntary muscles.
  • The lower part is made up of smooth muscles only.
  • The oesophagus consists of two sphincters.
  • The upper oesophagal sphincter is single ringlike cartilage which is both voluntary and involuntary in nature and it prevents food and liquids from entering the windpipe (trachea,)
  • The lower oesophagal sphincter is involuntary and prevents gastric acids from travelling into the oesophagus and it opens into the diaphragm.
  • So, the correct answer is 'Both voluntary and involuntary'.

The most distensible portion of the alimentary  canal is ________.

  1. Oesophagus

  2. Stomach

  3. Large intestine

  4. small intestine


Correct Option: B
Explanation:
  • The oesophagus is a hollow distensible muscular part of the alimentary canal.
  • The ability to stretch and expand is called distensibility.
  • The distensibility of the oesophagus allows any kind of food to pass through it with ease.
  • The oesophagus dilates and propels the food from the region of the pharynx to the stomach.
  • The stomach is a J shaped distensible bag like structure and is a highly distensible part of the alimentary canal.
  • It may take varying shapes and can hold about 1 litre of food.
  • The gastric folds in the inner walls of the stomach allow it to get expanded.
  • So, the correct answer is 'Stomach'.

What is the function of peristalsis in these parts?

  1. Oesophagus

  2. Stomach

  3. Small intestine

  4. Large intestine


Correct Option: A

Typhlosole found in Pheretima occurs in?

  1. Oesophagus

  2. Stomach

  3. Intestine

  4. Gizzard


Correct Option: A

The wall of alimentary canal from oesophagus to rectum possesses _________ layers.

  1. $2$

  2. $3$

  3. $4$

  4. $5$


Correct Option: A

The upper part of stomach is called ____ stomach. 

  1. fundic

  2. pyloric

  3. cardiac

  4. none of these


Correct Option: A

In case of vertebrates lacteals are found in 

  1. Oesophagus

  2. Ear

  3. Small intestine

  4. Ischium


Correct Option: A

What is the role of acid in our stomach?

  1. Acidify the food for proper action of pepsin

  2. Conversion of pepsinogen and prorenin into active forms of pepsin and renin

  3. Killing of microorganisms present in food

  4. All of the above


Correct Option: D
Explanation:

The gastric juice is made up of hydrochloric acid, pepsinogen and other digestive enzymes, gastrin, mucus, and bicarbonates. It has a pH ranging from 1 to 2. Its low pH is essential in activating digestive enzyme such as pepsinogen and convert it into the active pepsin, a Proteolytic activity of pepsin and in destroying various pathogens. 

Thus, the correct answer is option D.

Function of hydrochloric acid in the stomach is to

  1. Digest carbohydrates

  2. Clean the stomach

  3. Kill the germs

  4. Break down proteins


Correct Option: C
Explanation:

The stomach wall consists gastric gland which secretes gastric juice for digestion of food. The gastric juice is made up of hydrochloric acid, pepsinogen and other digestive enzymes, gastrin, mucus, and bicarbonates. It has a pH ranging from 1 to 2. Its low pH is essential in activating many digestive enzymes and in destroying various pathogens. Thus, the correct answer is option C.