The antibodies to the HIV virus may take up to three months to appear in the blood of the infected person.
Therefore, the second blood test is necessary three months after a person thinks that he/she has been exposed to HIV to check the presence of these antibodies and confirm whether the person is infected or not.
Answer:
Glossopteris and Lystrosaurus
Explanation:
Glossopteris is an ancient plant flora and Lystrosaurus is a fossil fauna, and both are found in many of the landmasses on earth. The Glossopteris flora appeared about 300 to 200 million years back and the Lystrosaurus appeared about 250 million years back on earth. They both existed from the time of late Permian to early Triassic age.
Both these fossils played an important role in understanding the continental drift theory or the plate tectonic theory. This evidence enabled geologists to understand how the continents have moved across the large ocean basin from one place to another and at what rate they are drifting currently. It helped in understanding how the super-continent Pangaea had broken into Laurasia and Gondwanaland, and further broken into the present location of the plates.
I believe this is called CTAATGT. Hope this helps.
