51.

The important gas which was absent during the formation of Earth is

• oxygen

• hydrogen

• nitrogen

• carbon dioxide

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

The carcinoma, a type of cancer, originates from

• blood

• connective tissue

• epithelial tissue

• lymph gland

Homo erectus evolved during

• Oligocene

• Pliocene

• Pleistocene

• Miocene

Which one of the following is not included under in situ conservation?

• National park

• Wild life sanctuary

• Zoological garden

• Biosphere reserve

Melting of DNA at an elevated temperature (70°C) is primarily due to the breakdown of

• phosphodiester bonds

• glycosidic bonds

• disulphide bonds

• hydrogen bonds

The usual source of restriction endonucleases used in gene cloning is from

• fungi

• bacteria

• plants

• viruses

For a clean environment, which one following is not essential?

• Producer

• Consumer

• Decomposer

• Polluter

Humoral immunity is mediated by

• cytotoxic T-cell

• plasma cell

• eosinophil

• neutrophil

The expanded name of MRI is

• Medical Reserach Instrument

• Magnetic Resonance Imaging

• Magnetic Research Institute

• Medical Resonance Imaging