Tag: biology

Questions Related to biology

Vallisneria spiralis is a classical example of

biology pollination and fertilization agents of pollination environmental conservation and biodiversity pollination, fertilization and development of endosperm and embryo

  1. Epihydrophily

  2. Hypohydrophily

  3. Anemophily

  4. Chiropterophily

Show answer
Correct Option: A
Explanation:

Pollination is the transfer of pollen from a male part of a plant (anther) to a female part of a plant (stigma), enabling later fertilisation and the production of seeds, most often by an animal or by the wind. Hydrophily is a fairly uncommon form of pollination whereby pollen is distributed by the flow of waters, particularly in rivers and streams. Epihydrophily is a pseudo hydrophily that occurs on the surface of the water. Vallisneria pollen grains are released on the surface of the water, which are passively carried away by water currents; some of them eventually reach the female flower.

So the correct option is 'epihydrophily'.

Select the incorrect statement.

biology digestive system digestion in small intestine digestive glands and their secretions alimentary canal

  1. Lipases and nucleases are not present in pancreatic juice.

  2. Goblet cells secrete mucus.

  3. Brunner's glands are sub-mucosal glands.

  4. Carboxypeptidase catalyses conversion of proteins, peptones and proteoses to dipeptides.

Show answer
Correct Option: A
Explanation:

The correct answer is (a).

Digestion of food
Which one of the following is the coned matching of the site of action on the given substrate, the enzyme acting upon it and the end product ?

biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

  1. Small intestine : Proteins $\overset{Pepsin}{\rightarrow}$ Amino acids

  2. Stomach : Fats $\overset{Lipase}{\rightarrow}$ Micelles

  3. Duodenum : Triglycerides $\overset{Trypsin}{\rightarrow}$ Monoglycerides

  4. Small intestine.: Starch $\overset{\alpha - amylase}{\rightarrow}$ Disaccharide (maltose)

Show answer
Correct Option: D

Isomaltase catalyzes the hydrolysis of bonds as shown in

biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

  1. glc(1-6)glc

  2. glc(1-4)glc

  3. gal(1-6)glc

  4. fru(1-6)glc

Show answer
Correct Option: A
Explanation:

Isomaltase is an enzyme that breaks the bonds linking saccharides, which cannot be broken by amylase or maltase. It digests polysaccharides at the alpha 1-6 linkages

So, the correct option is 'glc(1-6)glc'

Which of the following is a group of end products of carbohydrate digestion?

biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

  1. Glucose, galactose, maltose

  2. Sucrose, galactose, maltose

  3. Galactose, glucose, fructose

  4. None of the above

Show answer
Correct Option: C
Explanation:

The end product of carbohydrate digestion is mainly glucose together with some fructose and galactose (monosaccharide). 

Chylomicrons are __________________.

biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

  1. Fat droplets coated with phospholipids

  2. Fat droplets coated with cholesterol and protein

  3. Undigested proteins

  4. Undigested carbohydrates

Show answer
Correct Option: B
Explanation:

  • Fatty acids and glycerol being insoluble, cannot be absorbed into the blood. So, they are first incorporated into small droplets called micelles which move into the intestinal mucosa. 
  • They are then re-formed into very small protein coated fat globules called the chylomicrons which are transported into the lymph vessels (lacteals) in the villi. These lymph vessels ultimately release the absorbed substances into the bloodstream. Hence, chylomicrons are fat droplets coated with cholesterol and proteins.
So, the correct answer is 'fat droplets coated with cholesterol and proteins'.

Fat is completely digested in the

biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

  1. Stomach

  2. Mouth

  3. Small intestine

  4. Large intestine

Show answer
Correct Option: C
Explanation:
  • Digestion of some fats can begin in the mouth where lingual lipase breaks down some short chain lipids into diglycerides. However, fats are completely digested in the small intestine.
  • Fat is completely digested in the small intestine because it gets bile from the liver through gallbladder which is responsible for fat digestion.
  • Hence Fat is completely digested in the Small intestine.
  • So, the correct answer is 'Small intestine'.

Carbohydrates in the chyme are hydrolysed to disaccharide by amylase of 

biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

  1. Pancreatic juice

  2. Gastric juice

  3. Brunners gland

  4. Crypts of Lieberkuhn

Show answer
Correct Option: A
Explanation:

The chyme produced by digestion in the stomach is passed on to the small intestine for further digestion and absorption where the enzyme pancreatic amylase of the pancreatic juice converts the carbohydrates present in the chyme into disaccharides and monosaccharides. 

So, the correct answer is 'Pancreatic juice'.

(A) Teeth and tongue with help of saliva masticate and mixed up the food thoroughly.
(B) Mucus in saliva helps in lubricating and adhering the masticated food particles into chyme
(C) Mucus and bicarbonate present in gastric juice plays an important role in lubrication and protection from excoriation by highly concentrated $HCL$
(D) The function of bile is emulsification of fat and activation of lipase
How many sentences given above are true?

biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

  1. One

  2. Two

  3. Three

  4. Four

Show answer
Correct Option: D
Explanation:

  • During the mastication process, the food is positioned by the cheek and tongue between the teeth for grinding. 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.
  •  The salivary glands produce two different types of secretions: thin, watery saliva and thick mucus. This mucus is an excellent lubricant and makes swallowing food easier.
  • Secretion of bicarbonate into the adherent layer of mucus gel creates a pH gradient with a near-neutral pH at the epithelial surfaces in stomach and duodenum, providing the first line of mucosal protection against luminal acid.
  • Bile contains bile acids, which are critical for digestion and absorption of fats and fat-soluble vitamins in the small intestine. The function of bile is to bring ingested fats into the emulsion to facilitate the work of the lipases.

So, the correct answer is 'Four'.

Stomach is the site digestion mainly of ______________.

biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

  1. Carbohydrates

  2. Fats

  3. Proteins

  4. All of these

Show answer
Correct Option: C
Explanation:

The stomach is the site for the digestion of Protein. Pepsin present in duodenum breaks down the food proteins into polypeptides which are then broken down by various exopeptidases and dipeptidases into amino acids.

So, the correct answer is 'Proteins'.