Explain how the discoveries by Rosalind Franklin helped Watson and Crick build an accurate model of DNA.

Explanation:

n 1952, Rosalind Franklin produced an image of DNA that suggested it contained two strands twisted in a double helix with a phosphate backbone and bases inside.Franklin calculated the diameter of DNA, the distance between strands and bases, the angle of the helix, and the number of bases per coil.Watson and Crick used this information to build and accurate model of DNA.

Rosalind's x-ray showed that the ladders of nucleotides were inside a double helix.

Watson and Crick built models with the ladders on the outside.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.