“embryo sac”可以造什么句，embryo sac造句

Starch grains present in the embryo sac and placenta are utilized by the embryo.

Pollen tube entered the embryo sac via one synergid and in it released two sperms.

The development of the embryo sac conformed to the Polygonum type.

At the mature embryo sac stage, some nucellar cells at the chalazal region differentiated into hypostase.

Observation by paraffin section showed that Lipeng No.2 embryo sac mother cells were almost entirely degenerated during megasporogenesis.

Megaspore tetrad is linear. the chalazal megaspore develops into an embryo sac of polygonum type. Hypostase and special integument tapetum exist in the ovule.

When the free nuclei of the endosperm were 16 or 32, the nucellar embryo initial (s) originated from the nucellar cells near the micropylar end of the embryo sac.

The embryo sacs observation is one of the main study method for embryology.

The mature embryo sac has seven cells.

The central portion of an ovule in which the embryo sac develops;the megasporangium.

Observation of citrus embryo development showed that in 50 days or so after pollination there was only one zygotic embryo in the embryo sac, and nucellar embryo was not yet invaded.

A minute structure in seed plants, containing the embryo sac and surrounded by the nucellus, that develops into a seed after fertilization.

Those abnormal embryo sacs having abnormal fertility dued to no normal eggs, which caused seed setting rate to drop.

These abnormalities would cause the abnormal structure of mature embryo sac.

The concept of an alternation of generations can be extended to the flowering plants in which the embryo sac and pollen represent the much reduced famale and male gametophyte generations respectively.

Synergid cells Two haploid cells located near the egg cell at the micropylar end of the embryo sac in flowering plants.

Then the uninucleate embryo sac forms 7-celled or 8-nucleate embryo sac of polygonum type following its three times division successively.