Diagram of the evolution of land plants?

The diagram for evolution of plants in the 4 stages is attached below.

Explanation:

The plants evolution has 4 main periods:

A. 1st Period of Plant Evolution

About 420 million years ago, plants evolved from algae. Formation of cuticle was the first terrestrial adaption.

B. 2nd Period of Plant Evolution

Abut 400 million years ago, the diversification of vascular plants came into being. The early vascular plants lacked seeds.

C. 3rd Period of Plant Evolution

This was around 360 million years ago, that the seed evolved. The plants had seeds, but they did not have any covering, so they were called naked seeds. These plants were gymnosperms.

D. 4th Period of Plant Evolution

This was the evolution of flowering plants, happened around 130 million years ago (during early Cretaceous period). The flowering plants were called angiosperms.

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.