Given the age of the meteorite is 4.5 billion years old with 78 atoms of lead-206 the answer should be B. 156. The half-life of uranium-238 in order to decay into lead-206 is 4.46 billion years, which means that the original number of atoms is 156.
Answer:tailing at 3' end protects mRNA from attack by 3' exonuclease and 5' capping is useful for recognition of mRNA
Explanation:
The mRNA formed and released from the DNA template is known as primary transcript. In mammalian system, it undergoes intensive modification to become the mature mRNA.
Post transcription processing includes removal of Introns, splicing of exons, poly-A tailing at 3'end and capping at 5' end.
The Poly-A tailing at 3' end occurs in the nucleoplasm, the 3' end is polyadenlated involves with 20-250 nucleotides long. This tail protects mRNA from attack by 3' exonuclease activity
5' end capping end also is done in the nucleus. The cap is useful in recognition of mRNA by the translating machinery.
Answer:
Explanation:
NEAR remained in this orbit for 10 days and then was backed out in stages to a 100 km circular orbit by September 5, 2000. Maneuvers in mid-October led to a flyby of Eros within 5.3 km of the surface at 07:00 UT on October 26.
Launch date: February 17, 1996 20:43:27 UTC; ...
Closest approach: June 27, 1997 12:56 UTC; .
That represents geographical isolation.
Biological isolation is present where members of species are not able to produce fertile offspring due to the genetic incompatibility.
Temporal isolation includes differences in the seasons of mating. One species mates in season x and another in season y, means they will not be able to interbreed.
Anatomical isolation means there are differences in the physical structures of the species members that inhabit their ability to mate.
Answer: Permeable
Explanation: In the picture you can see that only the red ones can pass through.
