Last Universal Common Ancestor (LUCA)
20.07.2024
Last Universal Common Ancestor (LUCA)
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For Prelims: About LUCA |
Why in the news? In a new study, scientists have said the last universal common ancestor (LUCA) could have formed just a few hundred million years after the earth formed.
About LUCA:
- LUCA is the hypothesized common ancestor from which all modern cellular life, from single-celled organisms like bacteria to the gigantic redwood trees (as well as us humans), descends.
- LUCA represents the root of the tree of life before it splits into the groups recognized today: Bacteria, Archaea, and Eukarya.
- Modern life evolved from LUCA from various different sources: the same amino acids used to build proteins in all cellular organisms, the shared energy currency (ATP), the presence of cellular machinery like the ribosome and others associated with making proteins from the information stored in DNA, and even the fact that all cellular life uses DNA itself as a way of storing information.
- Through genetic analysis and evolutionary modeling, researchers pinpointed LUCA’s existence to about 4.2 billion years ago, just 400 million years after the formation of Earth and our Solar System.
- LUCA is not too different from modern prokaryotes and clearly possessed an early immune system.
Source: The Hindu
Ques :- Consider the following statements regarding Last Universal Common Ancestor (LUCA):
Statement-I
It is the hypothesized common ancestor from which all modern cellular life descends.
Statement-II
LUCA existed about one billion years ago.
Which one of the following is correct in respect of the above statements?
A.Both Statement-I and Statement-II are correct, and Statement-II is the correct explanation for Statement-I.
B.Both Statement-I and Statement-II are correct, and Statement-II is not the correct explanation for Statement-I.
C.Statement-I is correct, but Statement-II is incorrect.
D.Statement-I is incorrect, but Statement-II is correct.
Answer C