Gnetales is an order of the gymnospermic seed plants. This order is composed of three genera- Gnetum, Ephedra, and Welwitschia. Chamberlain (1935) has placed all three genera in a single-family Gnetaceae. But Markgraf (1951) has been split up the order Gnetales (due to the heterogeneous characters of those three genera) into three families (e.g., Ephedraceae ..read more

Coniferales is a group of gymnospermic plants. The members of this group form the common conifers. It includes both fossil and present-day living genera. Coniferales reached their maximum development probably during the late Jurassic period or the early Cretaceous period and then it began to decline. The members of Coniferales constitute dominant forest vegetation in ..read more

Biology Learner Ginkgoales: An Overview Ginkgoales is a gymnospermic order having one living genus (Ginkgo biloba). The members of this order once had an almost worldwide distribution in the Jurassic period. The fossil members of this order probably appeared in the Devonian period of the Paleozoic era, began to expand in the Triassic period, and reached their climax in the […] The post Ginkgoales: An Overview appeared first on Biology Learner written by Animesh Sahoo ..read more

Biology Learner Cycadales: An Overview Cycadales is a gymnospermic order. Members of this order are mostly inhabitants of tropical and subtropical regions. It includes both living and fossil genera. They originated in the Mesozoic era and continued up to the Jurassic and Cretaceous periods. Only ten genera are visible now. These genera are found in Australia, Central America, South Africa, […] The post Cycadales: An Overview appeared first on Biology Learner written by Animesh Sahoo ..read more

Sclerenchyma is a type of simple permanent tissue that provides structural support to the plant. It consists of thick-walled, lignified sclerenchyma cells. The cells mostly lack protoplasm at maturity and become dead. Mettenius first coined the term sclerenchyma. It is derived from the Greek words sclerous and enchyma. Sclerous means hard. Definition of Sclerenchyma Cells […] The post Sclerenchyma Cells: Structure, Types, Functions appeared first on Biology Learner written by Animesh Sahoo ..read more

Collenchyma is a simple permanent tissue composed of living cells with thickened walls. It is a part of the ground tissue and provides support and mechanical strength to the plants. The word collenchyma is derived from the Greek words colla and enchyma. Colla means give, and enchyma means infusion (i.e., tissue). Definition of Collenchyma Cells […] The post Collenchyma Cells: Structure, Types, Functions appeared first on Biology Learner written by Animesh Sahoo ..read more

Parenchyma is a simple permanent tissue that makes up large portions of various plant organs. It consists of thin-walled living parenchymatous cells. The word parenchyma comes from the Greek words para and enchyma. Para means besides, and enchyma means infusion (i.e., tissue). Parenchyma is called the fundamental tissue of the plant as it forms the […] The post Parenchyma Cells: Structure, Types, Functions appeared first on Biology Learner written by Animesh Sahoo ..read more

Fungi lack the chlorophyll pigment essential for independent existence. Hence, they must get their food from other living organisms or from dead or decaying organic matter. Economical fungi have great importance in various aspects, like increasing soil fertility, the uses of various industries, antibiotics, drugs, organic acids, and the production of enzymes, vitamins, and hormones […] The post Economic Importance of Fungi appeared first on Biology Learner written by Animesh Sahoo ..read more

Bacteria exert both deleterious and benefical effects on human life. Beneficial species liberate fertilizer elements for growing crops, destroy sewage and other wastes, and produce valuable chemicals. Some species are harmful for animals as well as humans. Beneficial and harmful aspects of bacteria are briefly discussed below: Beneficial Activities 1. To increase soil fertility 2. […] The post Economic Importance of Bacteria appeared first on Biology Learner written by Animesh Sahoo ..read more

The Pteridospermales or Cycadofilicales are characteristic gymnospermous plants that bore fern-like foliage, which in turn bore seeds that were unprotected. Hence, they are known as seed ferns. Pteridospermales is a very large order that includes a heterogeneous assemblage of tree-like organisms. The plants lived through the Carboniferous period, reached their climax, and became extinct in […] The post Pteridospermales (Cycadofilicales): An Overview appeared first on Biology Learner written by Animesh Sahoo ..read more