Answer: <u>Guanine
</u>
According to Chargaff's rule, the base pairing in the DNA and RNA is fixed. Adenine always pairs with Thymine in DNA and Uracil in RNA. Guanine pairs up with cytosine. This complementary base pairing is universal and constant. That's why amounts are also equal. It means if cytosine is 20% in any DNA sample, then amount of guanine would be 20% as well.
Answer:
Antibiotics killed the bacteria that cause infection but they can also kill beneficial bacteria . thus Ms ABC developed a yeast infection and diarrhea after course of antibiotics because antibiotics distrub natural balance of beneficial bacteria in her intestine.
ATP
NADPH
O2
Are the products formed
Answer:
The correct answer is D) short-lived plasma cells that secrete antibodies for the antigen
Explanation:
Each B lymphocyte has an antigen receptor (BCR: B cell receptor), a surface immunoglobulin (IgM or IgD), that binds to specific domains of the antigen called antigenic determinants or epitopes. Only B lymphocytes with a high antibody affinity for the antigen, and which are capable of processing and presenting it, will be positively selected. In this contact between the two cells, an exchange of chemical signals takes place that leads to the activation, clonal proliferation and differentiation of B cells into two sister subclones: one of antibody-secreting plasma cells, and the other of memory primed B cells. Therefore, only these last positively selected B lymphocytes will survive, proliferate and differentiate into plasma cells, synthesizing and secreting antibodies of a single isotypic class, with a unique specificity and high affinity, improving the ability to adhere to the antigen and, thus , neutralize and destroy pathogens.
