Tag: the living world

Enzymes synthesized by archaea (with optimal growth temperatures of >80 degree Celsius), also called hyperthermophilic enzymes, are typically thermostable ( that is resistant to irreversible inactivation at high temperatures) and are optically active at high temperatures. 

Thermophilic sulphur bacteria can survive at high temperatures between 41 and 122$^o$C and an optimum growth temperature which is higher than 75$^o$C. Hot spring blue-green algae have an optimum growth temperature of 45$^o$C. Methanogenic archaebacterium grows at an optimum temperature of 35-40$^o$C. Some marine archaebacteria are extreme thermophiles and grow at temperatures of 65- 80$^o$C. 

A plasmid is a small, circular piece of DNA that is different than the chromosomal DNA, which is all the genetic material found in an organism's chromosomes. It replicates independently of chromosomal DNA. Plasmids are mainly found in bacteria.

Thermophilic sulphur bacteria are found in hot springs and multiply at temperatutures 100-105$^0$C

The term Obligate anaerobes represent such microorganisms which can survive only in the absence of oxygen, i.e. presence of oxygen in their surrounding environment acts as a poison for them. Methane bacteria also called as methanogens are methane-producing bacteria which are obligate anaerobes as their metabolic processes do not require oxygen. Spirogyra are the green algae which produces oxygen. Pisum Sativum is commonly known as Green pea, which is a vegetable. Onion is also a vegetable.

The correct answer is D. 

Methanogens are responsible for methane gas production in biogas. Methanogen belongs to Archaebacteria class. Archeae are prokaryotic bacteria. They have no cell nucleus. They were initially classified as bacteria and hence called as Archaebacteria. 

• Halophiles are the prokaryotes that can be aerobic or anaerobic. 
• The phototropic anaerobic halophiles can trap solar energy for the synthesis of ATP i.e Adenosine Triphosphate with the help of ATP synthase enzyme. ATP is also known as the energy currency of a cell.
• The correct answer is C.

Methanogens are microorganisms that produce methane in absence of oxygen by the process called as methanogenesis. They belong to the kingdom Monera and the domain archaea. They use inorganic material as the source of energy such as hydrogen sulfide, elemental sulfur, ferrous iron, ammonia. They reduce carbon dioxide to methane and use hydrogen gas as an electron-donating reductant.