11. 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.
12. Which of the following is the best reason behind the fact that bats can fly in the dark? (UPSC Prelims 1979).
[A] Bats have a better vision in the dark
[B] The light startles them
[C] Bats produce high pitched sounds ultrasonic
[D] None of the above
Show Answer
Correct Answer: C [Bats produce high pitched sounds ultrasonic]
Notes:
The sounds that bats make are so high pitched that humans cannot hear them. High pitched sounds like this are called ultrasound. So, bats make high pitched squeaks while they fly. The echoes travel back to the bat and it can then tell how far away the objects are.
Bats use echoes or reflected sounds to determine the surrounding situation and to locate their prey. Often we see the bats fly at night. They fly in the dark so quickly without hitting anything. This process is called echolocation.
13. Which of the following facts is true regarding Colour blindness?
[A] More common among women
[B] Very rare in women
[C] Very rare in men
[D] Found to the same extent in both the sexes
Show Answer
Correct Answer: B [Very rare in women]
Notes:
Color blindness occurs when light-sensitive cells in the retina fail to respond appropriately to variations in wavelengths of light that enable people to see an array of colors. Photoreceptors in the retina are called rods and cones. It is very rare in women.
14. Which one of the following statements is not correct? (UPSC Prelims 2002)
[A] The boiling point of an aqueous solution is higher than that of pure water
[B] Addition of solutes to a solution causes an increase in its water potential
[C] The vapour pressure of the water in a solution is lower than that of pure water
[D] When a solution is separated from water by a semi permeable membrane, water movement can be prevented by applying pressure to the solution.
Show Answer
Correct Answer: B [Addition of solutes to a solution causes an increase in its water potential]
Notes:
Adding solute lowers the water potential. When a solution is enclosed by a rigid cell wall, the movement of water into the cell will exert pressure on the cell wall. This increase in pressure within the cell will raise the water potential.
15. Which of the following branch of biology deals with the study of Cartilage?
[A] Chondrology
[B] Chromatology
[C] Cnidology
[D] Conchology
Show Answer
Correct Answer: A [Chondrology]
Notes:
Chondrology is the branch of anatomy that deals with cartilage.
16. Hugo de Vries is related to which of the following theory of biology?
[A] aquatic ape theory
[B] modern anatomy
[C] Mutation Theory
[D] theory of evolution
Show Answer
Correct Answer: C [Mutation Theory]
Notes:
Hugo de Vries is a Dutch botanist and geneticist who pioneered the experimental study of biological evolution. His rediscovery of Gregor Mendel’s principles of heredity and his theory of biological mutation in 1900.
17. 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.
18. Which of the following is the simplest amino acid?
[A] Glycine
[B] Tyrosine
[C] Alanine
[D] Asparagine
Show Answer
Correct Answer: A [Glycine]
Notes:
Glycine is the simplest amino acid. It contains a single hydrogen atom as a side chain. It is also a type of proteinogenic amino acid.
19. Who among the following discovered the ribosome?
[A] George E. Palade
[B] Theodor Boveri
[C] Albert von Kolliker
[D] Robert Brown
Show Answer
Correct Answer: A [George E. Palade]
Notes:
Ribosomes were discovered by George E. Palade. He described them as small particles in the cytoplasm that were preferentially attached to the endoplasmic reticulum membrane.
20. Except which one is not useful in the treatment of viruses?
[A] acyclovir
[B] interferon
[C] penicillin
[D] antibodies
Show Answer
Correct Answer: C [penicillin]
Notes:
Acyclovir is a synthetic guanosine analog. It is used to treat herpes simplex virus (HSV) and varicella zoster virus (VZV) infections. Antibiotics are useless against viral infections.
