11. Which among the following is the name given to the ductless and secretory glands in the human body? (UPSC Prelims 1983)
[A] Endocrine glands
[B] Exocrine glands
[C] Salivary glands
[D] None of the above
Show Answer
Correct Answer: A [Endocrine glands]
Notes:
Ductless glands which are also known as internally secreting glands or endocrine glands secrete their products or hormones directly into the blood stream in response to instructions from the brain.
12. Corpus luteum is a mass of cells found in which organ? (UPSC Prelims 1997)
[A] brain
[B] ovary
[C] pancreas
[D] spleen
Show Answer
Correct Answer: B [ovary]
Notes:
The corpus luteum is a hormone-secreting structure that forms in the ovary after an egg has been released during ovulation. It is made up of cells that were part of the follicle that contained the egg, and it produces the hormones progesterone and estrogen, which help to support pregnancy. The corpus luteum is important for maintaining the lining of the uterus and preparing the body for pregnancy. If pregnancy does not occur, the corpus luteum will break down and be absorbed by the body.
13. Oxygen transportation in a human body takes place through
I. Blood
II. Lungs
III. Tissue
The correct sequence of transportation is (UPSC Prelims 1997)
[A] I, II, III
[B] III, I, II
[C] II, I, III
[D] I, III, II
Show Answer
Correct Answer: C [II, I, III]
Notes:
The lungs serve to exchange the two gases in the blood. Oxygen enters the blood from the lungs and carbon dioxide is expelled out of the blood into the lungs. The blood serves to transport both gases. Oxygen is carried to the cells and tissues.
14. 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.
15. The Six Kingdoms of Classification is also known as the latest classification system. By whom is it given?
[A] C Woese
[B] O Kandler
[C] Mc Wheels.
[D] Ernest Haeckel
Show Answer
Correct Answer: A [C Woese]
Notes:
In biology, a scheme of classifying organisms into six kingdoms: Proposed by Carl Woese et al: Animalia, Plantae, Fungi, Protista, Archaea/Archaeabacteria, and Bacteria/Eubacteria.
16. Which phylum does the salamander belong to?
[A] Mollusca
[B] Amphibians
[C] Reptiles
[D] Mammals
Show Answer
Correct Answer: B [Amphibians]
Notes:
Those organisms which can live on both land and water are called amphibians. Some examples of amphibians are frogs and toads, newts, salamanders and caecilians.
17. In which of the following organisms is the nuclear membrane absent?
[A] Nostoc
[B] Volvox
[C] Agaricus
[D] Penicillium
Show Answer
Correct Answer: A [Nostoc]
Notes:
Nostoc, also known as star jelly, troll’s butter, witch’s butter, and witch’s jelly, is a genus of cyanobacteria. Nostoc does not have a nuclear membrane. This is a characteristic of prokaryotic cells, which lack a nucleus. The genetic material in these cells is found in the cytoplasm, not enclosed within a nuclear membrane. On the contrary, Volvox, Agaricus, and Penicillium are all eukaryotic organisms, hence possess a nuclear membrane.
18. Which of the following contains an anticodon?
[A] tRNA
[B] mRNA
[C] rRNA
[D] DNA
Show Answer
Correct Answer: A [tRNA]
Notes:
An anticodon is found at one end of the transfer RNA (tRNA) molecule. During protein synthesis, each time an amino acid is added to the growing protein. A tRNA forms base pairs with its complementary sequence on the mRNA molecule and ensures that the appropriate amino acid is inserted into the protein.
19. Which of the following is not a type of fertilization?
[A] Porogamy
[B] Chalazogamy
[C] Mesogamy
[D] Gynogamy
Show Answer
Correct Answer: D [Gynogamy]
Notes:
Fertilization is a process of sexual reproduction, which is followed by pollination and germination. Porogamy, Chalazogamy, and Mesogamy are types of fertilization.
20. Which of the following helps in seed dispersal?
[A] Seeds
[B] Flowers
[C] Fruits
[D] None of these
Show Answer
Correct Answer: C [Fruits]
Notes:
Fruits are fleshy substances that usually surround the seeds. Flowers help in seed dispersal.