CBSE Questions for Class 11 Medical Biology Digestion And Absorption Quiz 9 - MCQExams.com

• William Beaumont revealed the functioning of human stomach in a living person. In 1833, He published his findings in the book, 'The Experiments and Observation of the Gastric juice and Physiology of Digestion'. After 10 years from there, he listed many conclusions about the chemical nature of digestion.
• He primarily discovered that gastric juice is responsible for the breakdown of food into simple nutrients and he also described the movement of stomach during digestion. 
• So, the correct option is B.
  

$$\textbf{Correct answer: D}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ Having fruits is one of the best diet plans because of the presence of natural nutrients and vitamins.

$$\textbf{Option (B):}$$ 

$$\textbf{Option (C):}$$ 

$$\bullet$$ Soft drink from the market is also another type of food that can disturb normal diet plans resulting in obesity.

$$\textbf{Option (D):}$$ 

$$\bullet$$ Therefore, both pizzas and soft drinks can cause this condition or symptoms related to improper digestion.

Hence, the correct answer is option (D).

$$\textbf{Correct answer: B}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ The hormones do not help in the digestion of food.

$$\bullet$$ It induces the secretion of the digestive enzymes that can facilitate the digestion process. 

$$\textbf{Option (B):}$$ 

$$\bullet$$ Digestive juice which includes the digestive enzymes is responsible for the proper digestion of the nutrients. 

$$\bullet$$ The macromolecules in the food and broken down into micromolecules in the presence of these enzymes. 

$$\bullet$$ The digestive juice includes both gastric juice and pancreatic juice containing different enzymes responsible for the digestion of nutrients. 

$$\textbf{Option (C):}$$ 

$$\bullet$$ Water is absorbed in the large intestine and it facilitates the movement of the food through the intestine. But it does not help in digestion directly. 

$$\textbf{Option (D):}$$ 

$$\bullet$$ Blood is responsible for transporting nutrients to the different regions of the body. 

$$\bullet$$ As the nutrients are absorbed in the intestine most of the nutrients enter the blood vessels present under the villi and then it is transported to the different cells of the body. 

$$\bullet$$ Fat is absorbed by the lymph to be transported to the adipocyte cells.

Hence, the correct answer is option (B).

$$\textbf{Correct answer: C}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ Humans have two sets of teeth. The first set of teeth which is present from birth to the ages of 8-12 years is the milk teeth.

$$\textbf{Option (B):}$$ 

$$\bullet$$ The milk teeth are also called temporary teeth or deciduous teeth because they are finally replaced after the age of 8 to 12 years.

$$\textbf{Option (C):}$$ 

$$\bullet$$ After 12 years the deciduous teeth fall off and the permanent teeth take their place.

$$\bullet$$ The permanent teeth are set to remain for the entire lifetime.

Hence, the correct answer is option (C).

• Food bolus from the esophagus enters the stomach. 
• The stomach is the dilated portion of the digestive tract where fragmented food that has been received from the oral cavity via the esophagus, is retained, macerated, and partially digested. Hence, Option C is correct. 

$$\textbf{Correct answer: D}$$ 

$$\textbf{Option (A):}$$ 

$$\textbf{Option (B):}$$ 

$$\bullet$$ There are 8 incisors of the 20 deciduous teeth. 

$$\textbf{Option (C):}$$ 

$$\bullet$$ There are 4 canines among the 20 deciduous teeth.

$$\textbf{Option (D):}$$ 

$$\bullet$$ There are no premolars as a part of the deciduous teeth.

$$\bullet$$ This type of teeth is not present because it is not necessary at the given age.

Hence, the correct answer is option (D).

• Heterocrine glands are the glands that function as both endocrine and exocrine glands in the body.
• The pancreas is one such gland.
• It operates as an endocrine gland in the digestive system by secreting pancreatic juice into the blood.
• These juices help break down fats and sugars.

• During prolonged fasting, first carbohydrates are used up ,then fats and then proteins are used at last.
  
• Carbohydrate and fat metabolism can easily produce energy than protein and they follow a more or less simpler pathway to enter into TCA cycle.
•  When all carbohydrates of the body are used up then fats are converted into carbohydrates and when all fats are used up then ultimately proteins of the body are converted into TCA cycle substrates to be used up by the body.

• Humans cannot digest cellulose as they lack enzyme cellulase which helps to digest cellulose.
  
• Caecum is a small blind sac which hosts some symbiotic micro-organisms that help in the digestion of cellulose.
• Vermiform appendix (a finger like tubular projection) arises from caecum, is vestigial (of no use) in humans. It is believed to be associated with cellulose digestion in early humans.

• The pylorus is a narrow cone-shaped constriction present at the end of the stomach and the beginning of the small intestine.
  
• It contains two region antrum which connects the parts of the stomach and pyloric canal that  connects the stomach to the small intestine.
  
• The main function of the pylorus (valve) is to prevent intestinal contents from reentering the stomach when the small intestine contracts to limit the passage of large food particles or undigested material into the intestine.