11. Which one of the following is not an essential micronutrient for plants? (UPSC Prelims 1996)
[A] Boron
[B] Zinc
[C] Sodium
[D] Copper
Show Answer
Correct Answer: C [Sodium]
Notes:
There are 13 essential nutrients required by plants for its healthy and proper growth. Now these nutrients are divided into two categories:
Macronutrients (nitrogen, phosphorus, potassium, calcium, magnesium and sulphur)
Micronutrients (iron, copper, manganese, zinc, boron, molybdenum and chlorine)
Additional mineral nutrient elements which are beneficial but not necessary are sodium, cobalt, vanadium, nickel, solenium, aluminium and silicon. Thus boron, zinc and copper falls into category of essential micronutrients while sodium does not.
12. Which of the following contain a protein named Alpha-keratin? (UPSC Prelims 1997)
[A] Blood
[B] skin
[C] wool
[D] eggs
Show Answer
Correct Answer: B [skin]
Notes:
Alpha-keratin, or α-keratin, is a type of keratin found in vertebrates. This protein is the primary component in hair, horns, mammalian claws, nails and the epidermis layer of the skin. α-keratin is a fibrous structural protein, meaning it is made up of amino acids that form a repeating secondary structure.
13. Consider the following statements with reference to the human body:
- The common bile duct releases its contents into the stomach.
- The pancreatic duct releases its contents into the duodenum.
Which of the above statements is/are correct? (UPSC Prelims 2006)
[A] I only
[B] II only
[C] Both I and II
[D] Neither I nor II
Show Answer
Correct Answer: B [II only]
Notes:
The common bile duct and the pancreatic duct both release their contents into the duodenum, not the stomach. The digestive enzyme (pancreatic juices) are released to the duodenum from the pancreatic duct.
14. What term is used for a gene that exhibits multiple effects?
[A] Pleiotropism
[B] Multitropism
[C] Complementary
[D] Allele
Show Answer
Correct Answer: A [Pleiotropism]
Notes:
Pleiotropism describes the genetic effect of a single gene on multiple phenotypic traits. A classic example of pleiotropy is phenylketonuria, a human disease that affects multiple systems but is caused by one gene defect. The underlying mechanism is that the gene codes for a product that is, for example, used by various cells, or has a signaling function on various targets.
15. Which vitamin is also called as “Folic acid”?
[A] Vitamin B3
[B] Vitamin B6
[C] Vitamin B9
[D] Vitamin B12
Show Answer
Correct Answer: C [Vitamin B9]
Notes:
Vitamin B9 is also called as the folic acid. Folic acid is converted into folate in the human body. Folate is essential for making DNA and RNA.
Extra info: Folic acid /B9 is recommended to the pregnants to reduce the risk of Neural Tube Defects in the foetus.
16. Which gas is released during the process of photosynthesis in plants?
[A] Carbon dioxide
[B] Methane
[C] Oxygen
[D] Nitrogen
Show Answer
Correct Answer: C [Oxygen]
Notes:
Inputs of photosynthesis are carbon dioxide and water and outputs are glucose and oxygen. Photosynthesis occurs in the presence of sunlight.
17. In the branch of biology, what is the transmission of paternal traits to progeny called?
[A] Genetics
[B] Heredity
[C] Gerontology
[D] Genetic Engineering
Show Answer
Correct Answer: B [Heredity]
Notes:
The transmission of characteristics from parent to offspring is called heredity, and can be inferred from inherited characteristics.
18. What is a nucleotide made of?
[A] purine, pyrimidine and phosphate
purine, pyrimidine and phosphate
[B] purine, sugar and phosphate
[C] nitrogen base, sugar and phosphate
[D] pyrimidine, sugar and phosphate.
Show Answer
Correct Answer: B [purine, sugar and phosphate]
Notes:
Nucleotide is an organic compound. It is a nitrogenous purine or pyrimidine base attached to a sugar (ribose or deoxyribose) and a phosphate group.
19. In cell culture, the measles virus can lead to which of the following?
[A] nuclear pyknosis
[B] transformation of cells
[C] syncytium formation
[D] rounding and aggregation of cells
Show Answer
Correct Answer: C [syncytium formation]
Notes:
In cell culture, the measles virus can lead to syncytium formation.
20. Gymnosperms are called naked seed plants because of the lack of which of the following?
[A] Cotyledon
[B] Endosperm
[C] Ovary Wall
[D] Testa
Show Answer
Correct Answer: C [Ovary Wall]
Notes:
Gymnosperms are called naked seed plants because of the lack of Ovary Wall.
