21. Which of the following non-metal has an isotope which can be used to detect secret nuclear fuel reprocessing facilities?
[A] Selenium
[B] Tellurium
[C] Neon
[D] Krypton
D [ Krypton ]
Notes:
Krypton-85 present in the atmosphere has been used to detect many secret nuclear fuel reprocessing facilities in North Korea and Pakistan.
22. Which element helped James Chadwick to discover Neutron?
[A] Lithium
[B] Beryllium
[C] Boron
[D] Carbon
B [Beryllium]
Notes:
Neutrons were discovered by James Chadwick by an experiment involving the bombardment of beryllium nucleus with α-particles.
23. Which of the following viruses is not linked to human cancer?
[A] Hepatitis C virus
[B] Hepatitis B virus
[C] Varicella-Zoster virus
[D] Herpes simplex virus type 2
C [Varicella-Zoster virus]
Notes:
Hepatitis C, Hepatitis B and Herpes simplex virus type 2 viruses which are linked to human cancer.
24. What kind of virus is measles?
[A] Enveloped RNA virus
[B] Coronaviridae
[C] Tobacco mosaic virus
[D] Npne of these
[A] Enveloped RNA virus
Notes:
Measles is caused by a single-stranded, enveloped RNA virus with a serotype 1. It is classified as a member of the genus Morbillivirus in the Paramyxoviridae family. Humans are the only natural host of the measles virus.
25. Which plant has spores and embryos, but does not have vascular tissue and seeds?
[A] Rhodophyta
[B] Bryophyta
[C] Pteridophyta
[D] Phaeophyta
B [Bryophyta]
Notes:
Bryophytes are a proposed taxonomic division. These three groups of non-vascular land plants include liverworts, hornworts and mosses. They are notably limited in size and prefer moist habitats. They can survive in dry environments.
26. Cooci which are mostly single or in pairs are called?
[A] Streptococci
[B] Diplococci
[C] Tetracocci
[D] None of these
B [Diplococci]
Notes:
A diplococcus is a round bacterium (a coccus). It usually occurs as two joined cells.
27. Cyanobacteria have__?
[A] Gram-positive cell wall
[B] Gram-negative cell wall
[C] Neither (a) nor (b)
[D] No cell wall
[B] Gram-negative cell wall
Notes:
Cyanobacteria are the first organisms known to produce oxygen. Cyanobacteria have a gram-negative cell wall.
28. Which of the following tissue provides strength to the plant?
[A] Intercalary
[B] Parenchyma
[C] Sclerenchyma
[D] Collenchyma
C [Sclerenchyma]
Notes:
Sclerenchyma provides strength to the plant. It is found in the covering of seeds and nuts, around the vascular tissues in stems and the veins of leaves.
29. What is the stage in which a plant slows down its cellular activity and sheds its leaves?
[A] Dormancy
[B] Abscission
[C] Tropisms
[D] None of these
[A] Dormancy
Notes:
Dormancy is the stage in which a plant slows down its cellular activity and sheds its leaves.
30. What causes ankylostomiasis disease?
[A] Pinworm
[B] Filarial worm
[C] Rundworms
[D] Hookworm
D [Hookworm]
Notes:
Hookworm causes ankylostomiasis disease. It causes anemia. They stick to the intestinal wall and suck the blood causing anemia.