At the time of the origin of luca which mode of nutrition was not being used?
a. chemoheterotroph
b. chemoautrophs.
c. photoautotrophs-oxygenic.
d. photoautotrophs-anoxygenic.

C. Photoautotrophs-oxygenic.

Explanation:

LUCA is an abbreviation of the ‘Last Universal Common Ancestor’. The LUCA was a microorganism which lived around 4 billion years ago. The evidence had shown that the LUCA was lived deep underground in hydrothermal vents. These vents were rich in iron-sulphur. It did not use air but made its food from the metal-rich environment surrounding it. It made organic compounds such as ammonia for its metabolism from elements such as hydrogen, carbon dioxide and nitrogen.

cats appear to have glowing cat eyes because the back of their eyeballs includes a special reflective surface called the tapetum lucidum. this lets them see better during the night, giving them a much better vision.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.