Answer:
This composition of nucleotide given in the question do not obey the chargaff"s rule.
Explanation:
According to chargaff"s rule the total number of purine bases will be same to the total number of pyrimidine bases that is
Adenine+Guanine=Thymine+Cytosine
But here the above quation is not maintained because according to the question A+G=49%
and T+C = 51%.
Such DNA is replicated by rolling circle model.
Answer:
Yes, Mass Extinctions May Have Been Caused By Meteors, as the probability of mass extinction occurring after an asteroid that could hit a random location on the Earth's surface was approximately 13% when the Chicxulub-scale asteroid hit the Earth.
Soot could be the main cause of mass extinction after an asteroid impact.
C. Precipitation fits the definition for “falling rain or snow”
Answer:
Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.
Explanation:
Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, which are expressed on the surface of antigen-presenting cells (APCs). Once activated, they divide rapidly and secrete cytokines that regulate or assist the immune response.
