Tag: biology

Quizzes (1160) Questions (12174)

Questions Related to biology

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

Vallisneria spiralis is a classical example of

  1. Epihydrophily

  2. Hypohydrophily

  3. Anemophily

  4. Chiropterophily
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.

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

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 ?

  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)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Starch is broken down by alpha-amylase into disaccharides like maltose in the small intestine. Option A is wrong because pepsin works in the stomach, and Option C is wrong because trypsin acts on proteins, not triglycerides.

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

Isomaltase catalyzes the hydrolysis of bonds as shown in

  1. glc(1-6)glc

  2. glc(1-4)glc

  3. gal(1-6)glc

  4. fru(1-6)glc
Reveal answer Fill a bubble to check yourself
A Correct answer
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'

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

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

  1. Glucose, galactose, maltose

  2. Sucrose, galactose, maltose

  3. Galactose, glucose, fructose

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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

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

Chylomicrons are __________________.

  1. Fat droplets coated with phospholipids

  2. Fat droplets coated with cholesterol and protein

  3. Undigested proteins

  4. Undigested carbohydrates
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.

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

Fat is completely digested in the

  1. Stomach

  2. Mouth

  3. Small intestine

  4. Large intestine
Reveal answer Fill a bubble to check yourself
C Correct answer
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'.
Multiple choice biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

Carbohydrates in the chyme are hydrolysed to disaccharide by amylase of 

  1. Pancreatic juice

  2. Gastric juice

  3. Brunners gland

  4. Crypts of Lieberkuhn
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.

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

(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?

  1. One

  2. Two

  3. Three

  4. Four
Reveal answer Fill a bubble to check yourself
D Correct answer
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'.

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

Stomach is the site digestion mainly of ______________.

  1. Carbohydrates

  2. Fats

  3. Proteins

  4. All of these
Reveal answer Fill a bubble to check yourself
C Correct answer
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'.