What molecule makes a trunk to a tree sturdy

Cellulose

Explanation:

In botany, trunk refers to the main wooden axis of a tree that supports the branches and is supported by and directly attached to the roots. The molecule that makes it sturdy is . Dead cellulose particles make trunk more strong.

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.