11. Which one of the following sets is correctly matched? (UPSC Prelims 1995)
[A] Diphtheria, Pneumonia and Leprosy : Hereditary
[B] AIDS, Syphilis and Gonorrhoea : Bacterial
[C] Colour blindness, Hemophilia and Sickle cell anaemia : Sex linked
[D] Polio, Japanese B encephalitis and plague : Viral
Show Answer
Correct Answer: C [Colour blindness, Hemophilia and Sickle cell anaemia : Sex linked]
Notes:
• If you are colorblind, you have difficulty distinguishing certain colors, such as blue and yellow or red and green. Color blindness is an inherited condition that affects males more frequently than females
• Hemophilia A and hemophilia B are inherited in an X-linked recessive pattern. The genes associated with these conditions are located on the X chromosome, which is one of the two sex chromosomes. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder.
• Sickle cell anemia is inherited as an autosomal recessive condition. This means that the gene can be passed on from a parent carrying it to male and female children.
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. The sensation of fatigue in the muscles after prolonged strenuous physical work is caused by? (UPSC Prelims 2000)
[A] a decrease in the supply of oxygen
[B] minor wear and tear of muscle fibres
[C] the depletion of glucose
[D] the accumulation of lactic acid
Show Answer
Correct Answer: D [the accumulation of lactic acid]
Notes:
The sensation of fatigue which the muscles feel after a prolonged and a strenuous physical workout is caused by the accumulation of lactic acid.
This is so because lactic acid buildup tends to cause fatigue and soreness in the muscles.
There is a burning sensation felt up in the muscles when buildup of acid happens in muscles during exercise. This is also known as acidosis.
14. In the context of the organic evolution, the loss of limbs of snakes is explained by which of the following phenomenon? (UPSC Prelims 2002)
[A] Use and disuse of organs
[B] adaptation to living in burrows
[C] natural selection
[D] inheritance of acquired characters
Show Answer
Correct Answer: A [Use and disuse of organs]
Notes:
In organic evolution, Lamarck believed that any particular part of the body that is put into more frequent use has tendency to develop stronger and better while that part of body which is put into less or no use has tendency to gradually disappear. So, loss of limbs in snake is an example of use and disuse of organs.
15. In a bisexual flower, if androecium and gynaecium mature at different times, what is the name given to the phenomenon? (UPSC Prelims 2004)
[A] Dichogamy
[B] Herkogamy
[C] Heterogamy
[D] Monogamy
Show Answer
Correct Answer: A [Dichogamy]
Notes:
Dichogamy The condition in which the male and female reproductive organs of a flower mature at different times, thereby ensuring that self-fertilization does not occur.
16. Which among the following is an autotroph?
[A] Honey bee
[B] Algae
[C] Grasshopper
[D] Butterfly
Show Answer
Correct Answer: B [Algae]
Notes:
Autotrophs are the organisms which are able to prepare their own food without depending on other organism. Auto means self and prophs means food. All the organisms which are capable of carrying photosynthesis are examples of autotrophs.
17. Robert Hooke is known for which of the following works?
[A] how messages pass between nerve cells in mammals
[B] first use of the word cell
[C] theory of punctuated equilibrium
[D] aquatic ape theory
Show Answer
Correct Answer: B [first use of the word cell]
Notes:
Robert Hooke is known for his discovery of the law of elasticity (Hooke’s law), for his first use of the word cell in the sense of a basic unit of organisms, and for his studies of microscopic fossils, which made him an early proponent of a theory of evolution.
18. Who among the following is considered as the father of microbiology?
[A] Stephen Hales
[B] Antonie Van Leeuwenhoek
[C] Edwin John Butler
[D] Pier Antonio Micheli
Show Answer
Correct Answer: B [Antonie Van Leeuwenhoek]
Notes:
Antoine van Leeuwenhoek used the single-lens microscope he built to make the first observations of bacteria and protozoa. Leeuwenhoek is universally acknowledged as the father of microbiology.
19. Which of the following possesses the characteristics of both plants and animals?
[A] Azolla
[B] Lycopodium
[C] Euglena
[D] Sphagnum
Show Answer
Correct Answer: C [Euglena
]
Notes:
Euglena is an example of the Protista kingdom and has both plant and animal characteristics.
20. The lysogenic state is controlled by the activity of the regulatory region of the lambda phage genome, this region is called?
[A] immunity repressor
[B] immunity operon
[C] operon repressor
[D] none of these
Show Answer
Correct Answer: B [immunity operon]
Notes:
The lysogenic state is controlled by the activity of the regulatory region of the lambda phage genome, this region is called immunity operon.
