Archive | Gymnosperm

In this article we will discuss about Pentoxylales. After reading this article you will learn about: 1. Systematic Position of Pentoxylales 2. Discovery of Pentoxylales 3. Distinguishing Features 4. Stem Genera 5. Leaves 6. Seed-Bearing Organ 7. Affinities 8. Conclusion. Contents: Systematic Position of Pentoxylales Discovery of Pentoxylales Distinguishing Features of Pentoxylales Stem Genera of Pentoxylales Leaves of Pentoxylales Seed-Bearing [...]

The following points highlight the three main steps involved in embryogency in cycas. The steps are: 1. Development of Zygote 2. Structure of Seed 3. Germination of Seed. Embryogency in Cycas: Step # 1. Development of Zygote: The diploid osspore or zygote is the first cell of the sporophyte. It contains dense cytoplasm and a large nucleus. The nucleus moves [...]

In this article we will discuss about Cycadales. After reading this article you will learn about: 1. Meaning of Cycadales 2. General Characters of Cycadales 3. Genera 4. Phylogency. Meaning of Cycadales: Cycadales, consisting of 11 living genera and more than 100 species, are distributed in both tropical and warm temperate regions of the world They appeared first in Upper [...]