embryo sac

Tropic movements in response to the stimulus of chemicals is called chemotropic movements. Example: Growth of pollen tube through the style towards the embryo sac..

Longitudinal section of a flower showing germination of pollen grains and the phenomenon of fertilization. One pollen tube has grown through the style and has entered the embryo sac through the micropyle The pollen tube enters into the ovule, through the micropyle. Inside the ..

Androecium is the male reproductive part of the flower. The individual units of androecium are called the . Stamens have four-lobed anthers that produce the male gametes within the pollen grains. Gynoecium is the female reproductive part of the flower. The individual units are called the carpe..

. Each carpel bears many ovules each of which contain one egg, the female gamete. Each ovule bears the embryo sac that contains the egg and the polar nuclei in addition to other structures. Transfer of pollen grains to the stigma is called pollination. Pollination may be self-po..

In rats, as in all vertebrates, sexes are separate. Male and female exhibit several differences in their external features. The Male reproductive system consists of a pair of testis that are enclosed in scrotal sacs, a pair of vas deferens, a seminal vesicle, ejaculatory duct and penis. T..

. Gymnosperms are heterosporous, producing two kinds of spores microspores and megaspores produced by separate sporangia. The two types of sporangia - microsporangia and megasporangia are found on special leaf like structures called sporophylls. The microsporangia represent the pollen sacs..