-Priyanti, Subject Matter Expert at Edumarz
Solution: Gymnosperms partly resemble both pteridophytes and angiosperms and form an intermediate group between the two. They have a sporophyte plant body and are heterosporous (produce haploid microspores and megaspores). Microspores give rise to a male gametophyte structure inside the microsporangia, which produce the pollen grain. Megaspores (1 out of the 4 generated at once) forms a multicellular female gametophyte bearing two or more archegonia (female sex organs). This structure is rudimentary as compared to that of angiosperms, and does not involve the ovary. Upon successful fertilization of the male and female gametes, the zygote gives rise to embryo and the ovules, to seeds. The seeds are not covered and hence termed as naked.
Angiosperms are a highly developed group of plants that, unlike gymnosperms, have flowers as their main organs for reproduction. The male (stamens) and female (carpels) reproductive organs are borne in whorls of flowers, and are known as androecium and gynoecium, respectively. The stamens bearing microsporangia (anthers) give rise to pollen grains. Carpels bearing ovules are the megasporophylls that have an ovary at its base. Pollen grains are trapped by the stigma, pass down the style, reach the ovary and fertilize the ovules. The zygote gives rise to the embryo, the ovary forms the fruit and the ovules, the seeds. Seeds are enclosed within the fruit.
Thus, both gymnosperms and angiosperms are seed-bearing plants having a well-developed vascular system, whose main difference lies in their mechanism and end result of reproduction.