Plants contain organs for sexual reproduction, located inside their flowers.
Male organs are called stamens. In the anther at the top of the stamen, pollen grains are produced which contain haploid sperm cells.
Female organs are called pistils. The pistil is vase-- shaped. At the top, is the stigma which is sticky to catch pollen grains. The style is a thin neck-like structure and this leads to the ovary at the bottom...
Plants contain organs for sexual reproduction, located inside their flowers.
Male organs are called stamens. In the anther at the top of the stamen, pollen grains are produced which contain haploid sperm cells.
Female organs are called pistils. The pistil is vase-- shaped. At the top, is the stigma which is sticky to catch pollen grains. The style is a thin neck-like structure and this leads to the ovary at the bottom of the pistil which contains ovules. These in turn, contain egg cells and polar cells.
Plants have a double fertilization. Once pollination occurs and pollen is transferred from the male stamen to the stigma at the top of a female pistil, the pollen grain germinates downward. A pollen tube forms and elongates. Once the tube reaches the ovary, it joins to the ovule and one sperm enters and fertilizes the egg cell located inside. This becomes the zygote and later, the embryo plant.
In flowering plants (angiosperms), another sperm enters the ovule and joins with the two polar nuclei to become endosperm material. This forms the food for the developing embryo plant. The ovule containing the embryo plant and food material develops a hard covering and is known as a seed. The ovary which contains the ovules expands in size to become the fruit.
Anything that contains seeds is therefore technically a fruit or ovary and the seeds are technically the ovules which contain an embryo plant with a food supply.
The link provided has nice illustrations of the male and female reproductive systems in angiosperms.
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