Classification of algae

Phaeophyceae

• Phaeophyceae, or brown algae, are mostly found in marine environments. Laminarin or mannitol are used to store food.
• They contain chlorophylls A and C, as well as carotenoids and xanthophylls.
• The plant body is usually held to the substratum by a holdfast and consists of a stalk, the stipe, and a leaf-like photosynthetic organ called the frond.
• They range in colour from olive green to brown, depending on the amount of the xanthophyll pigment fucoxanthin present.
• Sexual reproduction can be isogamous, anisogamous, or oogamous, with pyriform gametes bearing two laterally attached flagella.
• Vegetative reproduction occurs through fragmentation, while asexual reproduction occurs through pear-shaped biflagellate zoospores with two unequally attached flagella.
• The cellulosic wall of vegetative cells is usually covered on the outside by a gelatinous coating of align.
• Ectocarpus, Dictyota, Laminaria, Sargassum, and Fucus are the most common forms.

Chlorophyceae

• It is a large, loosely knit grouping of algae that contains the primary photosynthetic pigments chlorophyll a and b, as well as auxiliary pigments like xanthophylls and beta carotene.
• Green algae are used by higher organisms to perform photosynthesis. Other green algae species have symbiotic relationships with other organisms.
• Vegetative reproduction is usually accomplished through fragmentation or by different types of spores, asexual reproduction is accomplished through flagellated zoospores produced in zoosporangia.
• sexual reproduction is accomplished through the formation of sex cells, which can be isogamous, anisogamous, or oogamous.
• Chlorophyll a and b are photosynthetic pigments.
• Some foods are stored as starch, while others are stored as oil droplets.
• Pyrenoids, or storage bodies, are present.
• The inner layer of the cell wall is composed of cellulose, while the outer layer is composed of pectose.
• Unicellular, multicellular, colonial, and flagellates are all members. Spirogyra, Ulothrix, Volvox, and other prominent examples of green algae

Rhodophyceae

• Rhodophyceae is also known as red algae. They are mostly marine and only occasionally freshwater. For instance, Betrachospermum.
• They can be found in well-lit areas as well as deep ocean depths, and the thallus is multicellular.
• Chlorophyll a, d, and phycoerythrin are pigments found in red algae.
• Food is stored as Floridian starch, which is structurally similar to amylopectin and glycogen.
• The presence of the red pigment r-phycoerythrin causes the colour of algae to be red.
• Oogamy is a sexual reproduction process that results in complex post-fertilization developments.
• Asexual reproduction by nonmotile spores and vegetative reproduction by fragmentation
• Polysiphonia, Porphyra, Gracilaria, Gelidium, Betrachospermum, and other red algae are commonly found.

Algae, bryophytes, pteridophytes, gymnosperms, and angiosperms are all members of the plant kingdom. The first land plants appeared around 470 million years ago, and a spectacular amount of plant biodiversity has evolved over the aeons.

The plant kingdom is thought to play one of the most important roles in human life. Human survival would be impossible without the existence of plants. It is an open secret that plants are the primary source of the various vital components required for the survival of life on Earth.

The most important component is oxygen, without which most species would become extinct. This oxygen is released by plants during the photosynthesis process, in which green plants use the energy obtained from sunlight to help convert carbon dioxide into oxygen. This oxygen that humans have access to is critical for breathing and survival.