Question

True or false:

The right-handed DNA double helical structure called B-DNA is the one discovered by Watson and Crick. Z-DNA also can be found in cells but the helix turns in the opposite direction, forming a left handed helix.

Answer 1

The statement is true; Watson and Crick discovered the B-DNA structure, which is a right-handed helix. Z-DNA is a left-handed helical structure that also exists in cells.

Step-by-step explanation:

True, the right-handed DNA double helical structure known as B-DNA was indeed discovered by James Watson and Francis Crick. Watson and Crick's groundbreaking model revealed that DNA is composed of two strands twisted around each other to form a right-handed helix. The two strands are antiparallel and held together by hydrogen bonds forming between complementary nitrogenous bases, with adenine (A) pairing with thymine (T) and guanine (G) pairing with cytosine (C).

Z-DNA is also found within cells and is a left-handed helical structure that forms under certain conditions, such as high salt concentration or during active transcription. Unlike the Watson and Crick model of the B-DNA form, the Z-DNA helix turns in the opposite direction. The discovery of DNA's structure was not only a milestone in biology but also provided key insights into genetics and the process of DNA replication.