11. In which of the following plants, gametophyte is considered prothallus?
[A] Bryophyte
[B] Thallophyta
[C] Spermatophyte
[D] Pteridophyta
Show Answer
Correct Answer: D [Pteridophyta]
Notes:
Gametophyte is considered prothallus in Pteridophytes. Just as with seed plants and mosses, the life cycle of pteridophytes involves alternation of generations. This means that a diploid generation of the sporophyte, which produces spores is followed by a haploid generation i.e. the gametophyte or prothallus, which produces gametes.
12. Which of the following microorganisms causes Ring worm? (UPSC Prelims 1990)
[A] Bacterium
[B] Fungus
[C] Virus
[D] Worm
Show Answer
Correct Answer: B [Fungus]
Notes:
Ringworm isn’t a worm. It’s a skin infection that’s caused by moldlike fungi that live on the dead tissues of your skin, hair, and nails. It can occur at any place and on your scalp. When one gets it between the toes, it’s what people call athlete’s foot.
13. The sequencing of the entire genome (the totality of all genes) of an organism was completed in 1996. Which one of the following was that organism? (UPSC Prelims 1997)
[A] Albino mouse
[B] yeast
[C] human being
[D] Plasmodium vivax
Show Answer
Correct Answer: D [Plasmodium vivax]
Notes:
Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring malaria.
14. Consider the following conditions of sick human body
1. Swollen lymph nodes
2. Sweating at night
3. Loss of memory
4. Loss of weight
Which of these are the symptoms of AIDS? (UPSC Prelims 2003)
[A] 1 and 2
[B] 2, 3 and 4
[C] 1, 2 and 3
[D] 1, 2, 3 and 4
Show Answer
Correct Answer: D [1, 2, 3 and 4]
Notes:
AIDS is a viral disease. In this disease the immune system weakens and the body becomes prone to different type of infection by pathogens. Sweating at night, swollen lymph nodes, loss of memory and loss of weight are also symptoms of AIDS.
15. What field in which “Luc Montagnier” is famous for?
[A] Discovery of Ebola Virus
[B] Discovery of Influenza Virus
[C] Discovery of Human Immunodeficiency Virus
[D] Discovery of Polio Virus
Show Answer
Correct Answer: C [Discovery of Human Immunodeficiency Virus]
Notes:
Luc Antoine Montagnier (born 18 August 1932) is a French virologist and joint recipient, with Françoise Barre-Sinoussi and Harald Zur Hausen, of the 2008 Nobel Prize in Physiology or Medicine for his discovery of the human immunodeficiency virus (HIV). He has worked as a researcher at the Pasteur Institute in Paris and as a full-time professor at Shanghai Jiao Tong University in China.
16. In the branch of biology which of the following deals with the Study of kidney?
[A] Nephrology
[B] Neurology
[C] Neonatology
[D] None of these
Show Answer
Correct Answer: A [Nephrology]
Notes:
Nephrology is a specialty of adult internal medicine and pediatrics that deals with the study of the kidneys, particularly normal kidney function (kidney physiology) and kidney disease.
17. Who among the following has given four kingdom classifications?
[A] Ernest Haeckel
[B] Copeland
[C] RH Whittaker
[D] Carolus Linnaeus
Show Answer
Correct Answer: B [Copeland]
Notes:
Copeland introduced the Four kingdom of classifications(Monera, Protista, Plantae and Animalia).
18. A segment of DNA consists of 120 adenine and 120 cytosine bases. What is the total number of nucleotides present in the segment?
[A] 120
[B] 240
[C] 345
[D] 480
Show Answer
Correct Answer: D [480]
Notes:
According to Chargaff’s laws, the amount of adenine is always equal to that of thymine, and the amount of guanine is always equal to that of cytosine, i.e. A = T(120) and G = C (120), hence, the total no. The number of nucleotides would be 120 x 4 = 480.
19. Which one of the following plants has seeds but no flowers and fruits?
[A] Bryophytes
[B] Gymnosperms
[C] Mosses
[D] Pteridophytes
Show Answer
Correct Answer: B [Gymnosperms]
Notes:
Gymnosperms are a group of seed-producing plants. These include conifers, cycads, ginkgo and gnatophytes, which make up the clade gymnosperms. These living members are also known as acrogynosperms.
20. Which bacteria supply ammonia to soil?
[A] Rhizobium
[B] Lactobacillus
[C] Streptomyces
[D] Campylobacter
Show Answer
Correct Answer: A [Rhizobium]
Notes:
Rhizobium is an organic fertilizer. Biofertilizers are substances that contain microorganisms that, when applied to the soil, increase the amount of nutrients. It also enhances the growth of plants.
