Learn about the comparison of Angiosperms and Gymnosperms.
Angiosperms and Gymnosperms:
1. All gymnosperms are woody, although herbs are quite common in angiosperms.
2. Generally two types of branches are found in gymnosperms, i.e., long shoots and dwarf shoots.
3. The leaves of gymnosperms are evergreen and with thick cuticle.
4. Gymnosperms lack true vessels. Xylem vessels are absent and xylem parenchyma is scanty. Sieve plates are present on lateral walls. There are no sieve-tubes and companion cells. Only sieve cells and phloem parenchyma are present.
5. In gymnosperms the xylem is either mesarch or endarch. In angiosperms it is never mesarch.
6. Resin and gum canals are very common in gymnosperms.
7. In gymnosperms the leaves generally possess transfusion tissue and sunken stomata.
8. The aggregation of sporophylls in cones or strobili, in more advanced form, develop flower-like structure, but coloured bracts, perianth lobes and nectaries are absent.
9. Development of sporangium in gymnosperms is of eusporangiate type as also found in angiosperms.
10. The male gametophyte has two prothallial cells in Coniferales and Ginkgoales while one in Cycadales. No prothallial cells are found in angiosperms. One stalk cell and two male gametes which are flagellated in Cycadales and Ginkgoales while non-flagellate in rest of gymnosperms like that of angiosperms.
11. All gymnosperms are anemophilous and the pollen grains come in direct contact with the ovules (direct pollination). Here the pollen grains fall directly on the pollen drop which is sucked into the nucleus. In angiosperms the pollen grains are deposited on the receptive surface of the stigma (indirect pollination).
12. In gymnosperms, generally there is long interval between pollination and fertilization; in Amentiferae (angiosperms) long interval between pollination and fertilization exists. In Ginkgo and Cycas the pollen tube has haustorial function while in others it has sperm carrying function. The pollens possess wings in Pinus.
13. In gymnosperms, the ovule remains covered by one integument while in angiosperms there-are two integuments. In majority of gymnosperms the integument has a vasular supply while in angiosperms the vascular strand terminates at the base of the integuments.
14. In gymnosperms, the ovules are always naked and never enclosed in ovary as found in angiosperms.
15. In gymnosperms, germination of megaspore is accompanied by nuclear free division, ultimately resulting in the formation of female gametophyte.