Q21. The double helical structure of DNA was given by whom?
(A) H.G. Khurana
(B) Jacob and Monod
(C) Watson and Crick
(D) None of the above
(C) Watson and Crick
Q22. Which one of the following is not a characteristic of a virus?
(A) Presence of DNA or RNA
(B) Presence of cell wall
(C) Reproduction within the host cell
(D) Completely parasitic in nature
(B) Presence of cell wall
Q23. The pressure inside a soap bubble –
(A) Half the atmospheric pressure
(B) Less than atmospheric pressure
(C) is equal to atmospheric pressure
(D) is greater than atmospheric pressure
(D) is greater than atmospheric pressure
Q24. Who among the following discovered Potons?
(A) E. Rutherford
(B) J. Chadwick
(C) E. Goldstein
(D) J.J. Thomson
(C) E. Goldstein
Q25. What is the bacterial decomposition of organic matter under anaerobic conditions called?
(A) Composting
(B) Fermentation
(C) Fertilization
(D) Contamination
(B) Fermentation
Q26. Food cooks faster in a pressure cooker because
(A) Convection currents are generated inside the cooker
(B) At higher pressure water boils at lower temperature
(C) At higher pressure water boils at higher temperature
(D) Water boils only at 100°C but at higher pressure the amount of heat is greater
(C) At higher pressure water boils at higher temperature
Q27. The atomic number of an atom indicates the number of which of the following?
(A) Electron
(B) Neutron and proton
(C) Photon
(D) Neutron
(C) Photon
Q28. Yeast is a.
(A) Bacteria
(B) Bryophyta
(C) Algae
(D) Fungus
(D) Fungus
Q29. What is afla toxin made of?
(A) Virus
(B) Bacteria
(C) Kachak
(D) Algae
(C) Kachak
Q30. What are atoms called which have the same number of protons but varying number of neutrons?
(A) Samanyatronic
(B) Isomers
(C) Isotope
(D) Isobaric
(C) Isotope