Which is NOT correct according to the best known model for a DNA molecule?
..A. Adenine pairs with thymine, cytosine with guanine.
B. It is composed of two strands made up of nucleotides.
C. The strands are held together by strong chemical bonds between the sugars.
D. The strands are twisted into a helix.

yes? sounds right, but you didn’t ask a question.

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.

which

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements