Which of these is a Apdation for obtaining food.

A pleated woodpecker's bill

Explanation:

The bill is helping the woodpecker hammer the tree, which is how it gets its food.

a- all cells come from pre-existing cells

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.