Question

from the shape of dna
like most other scientists, pauling was not interested in dna until 1952.
but what was dna? scientists knew only a little. it came in long strands, and
each strand had a phosphorus - sugar backbone. there were also nucleic
bases, which stuck out from the backbone like knobs on a spine. but the
shape of the strands and how they linked up were mysteries—important
mysteries. as pauling showed with hemoglobin, shape can affect how
molecules work. soon the shape of dna became the most important
question in biology.
and pauling, like many others, assumed he was the only one smart
enough to answer this question. this wasnt, or at least wasnt only,
arrogance: pauling had simply never been beaten before. so in 1952,
pauling sat down at his desk in california to crack dna. he decided,
incorrectly, that the bulky nucleic bases sat on the outside of each strand
with the phosphorus - sugar backbone toward the molecules core. pauling
also reasoned that dna was a triple helix, with three ribbons of the
phosphorus - sugar backbones forming a spiral. unfortunately for pauling,
his data came from a dried - out dna sample, which made the molecule
seem more complicated. but on paper, all this seemed possible.
everything was humming along nicely until pauling asked a graduate
student to check his calculations. the student did and was soon tying
himself in knots trying to see where he was wrong and where pauling was.
eventually, the student pointed out to pauling that something about
theory didnt seem quite right.
ameïra l johnson,
what is the connection of william bragg to the
eventual solving of the dna mystery?

1. he is the scientist who got credit for the wor

because his lab was used by watson and cri
for research.

1. he authorized additional work on the topic

and pushed watson and crick to continue
pursuing an answer.

1. his contact with other scientists allowed

information to be shared that was then used
by watson and crick.

1. his work served as the basis of what became

the final model and what watson and crick
used as their inspiration.

Explanation:

To solve this, we analyze each option:

• Option 1: The text doesn't mention Bragg's lab being used by Watson and Crick for research credit. Eliminate.
• Option 2: There's no info about Bragg authorizing work or pushing Watson and Crick. Eliminate.
• Option 3: The passage doesn't talk about Bragg's contact with scientists sharing info used by Watson and Crick. Eliminate.
• Option 4: The context implies Bragg's work (related to X - ray crystallography, a key technique in DNA structure research) served as a basis or inspiration for Watson and Crick's final model, which aligns with the scientific history of DNA structure discovery.

Answer:

1. His work served as the basis of what became the final model and what Watson and Crick used as their inspiration.