Maximum DNA synthesis during the midproliferative phase of the cycle (i.e. cycle days 8â10) correlates with the maximum number of mitoses in both the stromal and epithelial endometrial cellular elements, as well as with the midproliferative peak of plasma estradiol and nuclear estradiol receptors.
Some defining characteristics of angiosperms include flowers, carpels, and the presence of endosperm, a nutritive substance found in seeds, produced via a second fertilization event. However, some current studies suggest that endosperm is not unique to angiosperms.
An angiosperm ovule contains an egg cell and a diploid fusion nucleus, which is created through the joining of two polar nuclei within the ovule. When a pollen grain comes into contact with the stigma, or top of the pistil, it sends a pollen tube down into the ovary at the pistil's base.n order for fertilization to occur, angiosperms either self-pollinate, in which a particular plant fertilizes itself, or cross-pollinate, in which one plant is fertilized by another of the same species.