Chargaff's analysis of the relative base composition of dna was significant because he was able to show that
a) the relative proportion of each of the four bases differs within individuals of a species.
b) the human genome is more complex than that of other species.
c) the amount of a is always equivalent to t, and c to g.
d) the amount of ribose is always equivalent to deoxyribose.
e) transformation causes protein to be brought into the cell.

C) The amount of A is always equivalent to T, and C to G

Explanation:

Chargaff's rule was given by the Austrian chemist, Erwin Chargaff in late 1940s. It explains the composition of the four bases i.e. Adenine(A),  Guanine(G), Thymine(T) and Cytosine(C) in a DNA molecule. According to it, purine and pyrimidine bases are always found in 1:1 ratio in a DNA molecule. A and G are purine and T and C are pyrimidine bases and a purine always forms a pair with pyrimidine base hence the amount of A will always be equal to T and amount of G will always be equal to C. This rule forms the basis for the Watson and Crick pairs in DNA double helix model.

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.