The important gas which was absent during the formation of Earth is
oxygen
hydrogen
nitrogen
carbon dioxide
A.
oxygen
The primitive atmosphere of Earth was devoid of oxygen gas. In primitive atmosphere, hydrogen atoms were most numerous and most reactive. They combined· with all available oxygen atoms and formed water, which is very important for life.
The carcinoma, a type of cancer, originates from
blood
connective tissue
epithelial tissue
lymph gland
Melting of DNA at an elevated temperature (70°C) is primarily due to the breakdown of
phosphodiester bonds
glycosidic bonds
disulphide bonds
hydrogen bonds
For a clean environment, which one following is not essential?
Producer
Consumer
Decomposer
Polluter
The expanded name of MRI is
Medical Reserach Instrument
Magnetic Resonance Imaging
Magnetic Research Institute
Medical Resonance Imaging
In spermatogenesis, reduction division of chromosome occurs during conversion of
spermatogonia to primary spermatocytes
primary spermatocytes to secondary spermatocytes
secondary spermatocytes to spermatids
spermatids to sperms
Which one of the following is not included under in situ conservation?
National park
Wild life sanctuary
Zoological garden
Biosphere reserve
The usual source of restriction endonucleases used in gene cloning is from
fungi
bacteria
plants
viruses
