11. What is the name of the hormone produced by thymus gland?
[A] Thyroxine
[B] Auxins
[C] Cytokinins
[D] Thymosin
Show Answer
Correct Answer: D [Thymosin]
Notes:
The thymus gland produces the hormone thymosin. Thymosin stimulates the development of T cells, which fight disease. The thymus gland is located in the chest, between the lungs and behind the breastbone. It is active until puberty, after which it shrinks and is replaced by fat.
The thymus gland also produces thymopoietin and thymulin. Thymopoietin is a polypeptide hormone made up of 49 amino acids.
12. Which of the following are chlorophyll-bearing, simple, thalloid, autotrophic and largely acquatic(both fresh water and marine) organisms?
[A] Gymnosperms
[B] Bryophytes
[C] Pteridophytes
[D] Algae
Show Answer
Correct Answer: D [Algae]
Notes:
Algae is an informal term for a large, diverse group of photosynthetic eukaryotic organisms that are not necessarily closely related, and is thus polyphyletic.
13. Which of the following Vitamin is responsible for anti-sterile activities? (UPSC Prelims 1979).
[A] Vitamin A
[B] Vitamin B
[C] Vitamin E
[D] Vitamin D
Show Answer
Correct Answer: C [Vitamin E]
Notes:Vitamin E is known as anti-sterility vitamin or fertility vitamin. It is chemically called as tocopherol. Vitamin E deficiency occurs rarely in adults. Much like vitamin C, vitamin E is another powerful anti-oxidant. Vitamin E is used during testosterone synthesis. Sperm production or spermatogenesis requires vitamin E as well as zinc. Following symptoms have been associated with vitamin E deficiency in humans:
- Muscular weakness & dystrophy, nocturnal muscle cramps
- Neurological disorders
- Degeneration of liver (hepatic necrosis)
- Shortened life-span of RBCs
14. Which of the following forms of Nitrogen is taken up by Higher Plants? (UPSC Prelims 1979).
[A] Nitrites only
[B] Nitrates only
[C] Nitrates and Ammonium
[D] Urea
Show Answer
Correct Answer: C [Nitrates and Ammonium]
Notes:
Plants absorb ammonium and nitrate during the nitrogen assimilation process, after which they are converted into nitrogen-containing organic molecules, such as amino acids and DNA. Animals cannot absorb nitrates directly. They receive their nutrient supplies by consuming plants or plant-consuming animals.
15. Malaria fever is caused by which of the following reasons? (UPSC Prelims 1991)
[A] Immediately after mosquito bite
[B] Upon disintegration and bursting of red blood cells
[C] When the malaria causing germs reach the liver
[D] Upon release of toxins into blood
Show Answer
Correct Answer: D [Upon release of toxins into blood]
Notes:
Malaria is a life-threatening disease. It’s typically transmitted through the bite of an infected Anopheles mosquito. Infected mosquitoes carry the Plasmodium parasite. When this mosquito bites you, the parasite is released into your bloodstream.
16. Who among the following carries the Haemophilia, a hereditary disease? (UPSC Prelims 1993)
[A] females and expressed by females
[B] females and expressed by males
[C] males and expressed by females
[D] males and expressed by males
Show Answer
Correct Answer: B [females and expressed by males]
Notes:
If he inherits his mother’s other X chromosome, he will have normal blood clotting. So a carrier’s son has a 50% chance of having hemophilia. A baby girl will inherit an X chromosome with a dominant gene for normal blood clotting from her father. So the daughter will not have hemophilia.
17. Which of the following arteries supplies blood to the heart? (UPSC Prelims 1997)
[A] Carotid arteries
[B] Hepatic arteries
[C] Coronary arteries
[D] Pulmonary arteries
Show Answer
Correct Answer: C [Coronary arteries]
Notes:
The aorta (the main blood supplier to the body) branches off into two main coronary blood vessels (also called arteries). These coronary arteries branch off into smaller arteries, which supply oxygen-rich blood to the entire heart muscle. The right coronary artery supplies blood to the right side of the heart.
18. Which branch of biology is known for the study of internal body structure?
[A] Anatomy
[B] Biometrics
[C] Pathology
[D] None of these
Show Answer
Correct Answer: A [Anatomy]
Notes:
Anatomy is the branch of biology that studies the structure and parts of organisms. Anatomy is a branch of natural science that deals with the structural organization of living things.
19. Who discovered cell differentiation?
[A] Walther Flemming
[B] Edwin John Butler
[C] Karl Ernst von Baer
[D] Parthasarthy Iyengar
Show Answer
Correct Answer: A [Walther Flemming]
Notes:
Cell differentiation is the process by which dividing cells change their functional or phenotypic type. All cells probably derive from stem cells and acquire their functions when they mature. Walther Flemming discovered cell differentiation.
20. Which of the following group is used to represent disease-related fungi?
[A] Penicillium
[B] Truffles, mushrooms and morels
[C] Smuts, rusts and moulds
[D] All of the above
Show Answer
Correct Answer: C [Smuts, rusts and moulds
]
Notes:
Smuts, rusts, and molds groups is used to represent disease-related fungi.