UPSC 2007 Science and Technology Questions with Answers
22 previous year UPSC Prelims questions on Science and Technology in the UPSC 2007 Prelims. Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 21–22 of 22 questions
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UPSC 2007Science and Technology · Biology: Zoology
Q21. Which one of the following is not a digestive enzyme in the human system?
Explanation
Gastrin is a hormone, not an enzyme. It is produced by G cells in the stomach lining. Gastrin stimulates the secretion of gastric acid (HCl) from parietal cells in the stomach, which aids in digestion. Options (a), (c) and (d) are incorrect:
Trypsin is a digestive enzyme produced by the pancreas and released into the small intestine. It plays a key role in breaking down proteins into smaller peptides, which are further digested into amino acids. It is part of the group of enzymes known as proteases and is essential for protein digestion. Ptyalin is also known as salivary amylase is a digestive enzyme produced in the salivary glands. It begins the process of digesting carbohydrates by breaking down starch into simpler sugars in the mouth. It is essential for the initial stage of carbohydrate digestion. Pepsin is a digestive enzyme secreted by the stomach in an inactive form (pepsinogen). It becomes active in the acidic environment of the stomach and breaks down proteins into smaller peptides.
UPSC 2007Science and Technology · Biology: Zoology
Q22. Which one of the following is the correct sequence in the order of decreasing length of the three structural parts given below of small intestine in the human body?
Explanation
The small intestine is an essential part of the human digestive system, responsible for digesting food and absorbing nutrients. It consists of three sections: the duodenum, jejunum, and ileum. The ileum is the longest part of the small intestine, measuring approximately 2.5 meters in length. It makes up the last part of the small intestine, connecting to the large intestine through the ileocecal valve. It is rich in villi (tiny finger-like projections) that increase the surface area for nutrient absorption. It absorbs essential nutrients like vitamins (B12), fat-soluble vitamins, and bile salts. The jejunum is about 2.5 meters long. While it is shorter than the ileum, it is thicker and has a more vascular structure. It is the primary site for the absorption of nutrients from digested food. It is specially adapted to absorb proteins, carbohydrates, and lipids. Its walls are lined with a large number of villi that aid in nutrient absorption. The rich blood supply to the jejunum allows for efficient nutrient transport to the rest of the body. The duodenum is the shortest section of the small intestine, measuring only about 25-30 cm (10-12 inches). It is the first part of the small intestine and connects to the stomach through the pyloric sphincter. The duodenum plays a crucial role in the chemical digestion of food. It receives digestive enzymes from the pancreas and bile from the liver and gallbladder. The duodenum is where most of the digestive action occurs before food moves into the jejunum and ileum for nutrient absorption. The duodenum’s role in digestion is so vital that it’s often called the "chemical reactor" of the body Thus, the correct sequence in decreasing order of length is:
Ileum > Jejunum > Duodenum.
Answer key for these questions
Q
UPSC year
Correct answer
21
2007
(b) Gastrin
22
2007
(d) Ileum - Jejunum - Duodenum
Frequently asked questions
How many previous year UPSC questions are there on Science and Technology?
This page covers 22 previous year UPSC Prelims GS Paper-I questions on Science and Technology in the UPSC 2007 Prelims, asked from 1996 to 2025. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for Science and Technology?
Questions on Science and Technology in the UPSC 2007 Prelims are available for 30 years, from 1996 to 2025. Use the Year filter to practise a single paper.
