Plant Biology and Classification

 Ectophloic siphonostele is a type of stele with pith that has the phloem only on the outside of the xylem. It is found in Marsilea and Botrychiun.

Spirogyra (pond silk) belongs to the division Chlorophyta. Spirogyra is a green algae.

Spirogyra is eutropic as it is highly rich in nutrients.

There are 5.1 million species of fungi that exist. Thus, it represents a group having the greatest number of species among global biodiversity.

The gymnosperms and angiosperms together compose the spermatophytes or seed plants.

Conifers form the largest group of living gymnosperms. Conifers have a total of 65-70 genera and 600-630 species.

Non-motile spores are formed in conifers.

Bennettitales are fossil gymnosperms.

The Pinaceae are always monoecious and include the common pines, firs, larches and spruces.

Pinophytes, also called conifers, are also the tallest and most massive living organisms; coast redwoods (Sequoia sempervirens) can exceed 100 metres (328 feet) in height and the giant sequoia (Sequoiadendron giganteum) can have a girth of 31 metres (101.5 feet) in circumference.

Blue-green algae are called cyanobacteria because they are photosynthetic bacteria containing blue-green pigments. Red algae have phycoerythrin, brown algae have fucoxanthin, and green algae have chlorophyll like plants.

Grana are absent in the chloroplast of algae.

Type of pigmentation of cell wall is the main criterion on the basis of which different forms of algae have been classified like red, green and brown algae.

Phycophytes are autotrophic and synthesise their own food in the presence of sunlight. Their sex organs are non-jacketed and the zygotes secrete thick wall to protect themselves from harsh climatic conditions.

The green algae (singular: green alga) are the large group of algae from which the higher plants emerged. Green algae are eukaryotic organisms that follow a reproduction cycle called alternation of generations.