11. Which of the following correctly defines an Antigen? (UPSC Prelims 2002)
[A] Lowers body temperature
[B] destroys harmful bacteria
[C] triggers the immune system
[D] is used as an antidote to poison
Show Answer
Correct Answer: C [triggers the immune system]
Notes:
An antigen is any substance that causes your immune system to produce antibodies against it. An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also form inside the body.
12. Which branch of biology is known for the study of fruits?
[A] Pomology
[B] Agronomy
[C] Floriculture
[D] None of these
Show Answer
Correct Answer: A [Pomology]
Notes:
Pomology is a branch of botany that studies fruit and its cultivation.
13. Serology is related to which of the following statements?
[A] Study of dietetics
[B] Study of snakes
[C] Study of serum
[D] Study of seeds
Show Answer
Correct Answer: C [Study of serum]
Notes:
Serology is the study of blood serum (the clear fluid that separates when blood clots).
14. Who among the following is considered to be the father of neuroscience?
[A] Santiago Ramón y Cajal
[B] James Black
[C] Erwin Chargaff
[D] Jacques Cousteau
Show Answer
Correct Answer: A [Santiago Ramón y Cajal]
Notes:
Santiago Ramón y Cajal is often called the father of neuroscience. He won the Nobel Prize for Physiology/Medicine in 1906 for his theory, which became known as the neuron theory.
15. What is a jelly-like substance found floating inside the plasma membrane called?
[A] Cell sap
[B] Cytoplasm
[C] Karyoplasm
[D] Mitochondria
Show Answer
Correct Answer: B [Cytoplasm]
Notes:
The jelly-like substance inside the plasma membrane in which all the organelles float is called cytoplasm.
16. Which of the following is not true about virus?
[A] Reproduce independently
[B] Contain DNA
[C] Contain RNA
[D] Are extracellular
Show Answer
Correct Answer: A [Reproduce independently]
Notes:
A virus is an infectious agent of small size and simple structure that can multiply only in living cells of animals, plants or bacteria. A virus particle is made up of genetic material housed inside a protein shell, or capsid. The genetic material, or genome, of a virus may be composed of single-stranded or double-stranded DNA or RNA. It can be linear or circular.
17. Bacteria come under which type of organisms?
[A] Single-celled
[B] Microscopic
[C] Living
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Bacteria are single-celled microorganisms that do not have a nucleus and other cell organelles. They are classified as prokaryotic organisms.
18. Iodine is obtained from which of the following members?
[A] Green algae
[B] Brown algae
[C] Red algae
[D] Blue green algae
Show Answer
Correct Answer: B [Brown algae]
Notes:
Kelp such as Fucus and Laminaria are rich sources of iodine. They are members of the Phaeophyceae brown algae.
19. In which of the following colour, rate of photosynthesis is maximum?
[A] Red
[B] Blue
[C] Green
[D] Yellow
Show Answer
Correct Answer: A [Red]
Notes:
The rate of photosynthesis is maximum in red colour and minimum in yellow colour. This happens because in the absorption spectrum, the red and blue colour gets absorbed and the majority of green light gets reflected.
20. In which of the following colour, rate of photosynthesis is minimum?
[A] Red
[B] Blue
[C] Green
[D] Yellow
Show Answer
Correct Answer: D [Yellow]
Notes:
The rate of photosynthesis is minimum in yellow colour and maximum in red colour. This happens because in the absorption spectrum, the red and blue colour gets absorbed and the majority of green light gets reflected.
