Apna phone number register karein. Ab aap Whatsapp pe solutions paa saktey h, hum aapko message karenge. Ab aap Whatsapp pe solutions paa saktey h, hum aapko ping karenge. Study Materials. Why use Doubtnut? Instant Video Solutions. Request OTP. Updated On: Share This Video Whatsapp. The red algae are multicellular and are characterized by a great deal of branching, but without differentiation into complex tissues.
Most of the world's seaweeds belong to this group. Although red algae are found in all oceans, they are most common in warm-temperate and tropical climates, where they may occur at greater depths than any other photosynthetic organisms. Most of the coralline algae, which secrete calcium carbonate and play a major role in building reefs, belong here. Red algae are a traditional part of oriental cuisine. There are known marine species of red algae; a few species occur in freshwater.
C yanobacteria : phylum of prokaryotic aguatic bacteria that obtain their energy through photosynthesis. They are often referred to as blue-green algae , even though it is now known that they are not related to any of the other algal groups, which are all eukaryotes. Cyanobacteria may be single-celled or colonial. Depending upon the species and environmental conditions, colonies may form filaments, sheets or even hollow balls.
Some filamentous colonies show the ability to differentiate into three different cell types. Despite their name, different species can be red, brown, or yellow; blooms dense masses on the surface of a body of water of a red species are said to have given the Red Sea its name. There are two main sorts of pigmentation. Most cyanobacteria contain chlorophyll a , together with various proteins called phycobilins, which give the cells a typical blue-green to grayish-brown colour. A few genera, however, lack phycobilins and have chlorophyll b as well as a , giving them a bright green colour.
Unlike bacteria, which are heterotrophic decomposers of the wastes and bodies of other organisms, cyanobacteria contain the green pigment chlorophyll as well as other pigments , which traps the energy of sunlight and enables these organisms to carry on photosynthesis. Cyanobacteria are thus autotrophic producers of their own food from simple raw materials. Nitrogen-fixing cyanobacteria need only nitrogen and carbon dioxide to live: they are able to fix nitrogen gas, which cannot be absorbed by plants, into ammonia NH 3 , nitrites NO 2 or nitrates NO 3 , which can be absorbed by plants and converted to protein and nucleic acids.
Cyanobacteria are found in almost every conceivable habitat, from oceans to fresh water to bare rock to soil. Cyanobacteria produce the compounds responsible for earthy odors we detect in soil and some bodies of water. The greenish slime on the side of your damp flowerpot, the wall of your house or the trunk of that big tree is more likely to be cyanobacteria than anything else.
Cyanobacteria have even been found on the fur of polar bears, to which they impart a greenish tinge. In short, Cyanobacteria have no one habitat because you can find them almost anywhere in the world. Related topics. Toggle navigation. Algae description and types Algae The word algae represents a large group of different organisms from different phylogenetic groups, representing many taxonomic divisions.
Types of algae The main phylogenetic groups of algae are [1] , [2] : Diatoms : unicellular organisms of the kingdom protista, characterized by a silica shell of often intricate and beautiful sculpturing. Apart from Phaeophyta, other phyla that have predominant brown pigment apart from chlorophyll are Dinoflagellata dinoflagellates and olive-brown Bacillariophyta diatoms.
Golden algae are those belonging to the phylum Chrysophyceae. They are distinguished mainly by the presence of two specialized flagella wherein one has mastigonemes and the other is smooth. Prymnesium parvum is one of the well-known golden algae due to its association with fish kills. The blue-green algae include the members of the Cyanophyta. They are not considered by other references as algae since they are prokaryotes.
Nevertheless, they are similar to other algal species in being photosynthetic due to the presence of chlorophyll. Aside from this pigment, blue-green algal cell also has phycobiliproteins that make them blue-green in color thus, the name.
Algae, in their natural habitat, are important as they account for half of the photosynthetic production of organic material on earth. They serve as food for aquatic animals. Some of them also live in symbiosis, such as lichens. Lichen is a symbiotic association between algae and fungi on terrestrial habitats. The presence of lichen could indicate the pollution status of the environment. Algae are used in different industries.
For instance, kelps brown macroscopic algae are harvested, dried, and processed for the commercial production of soap, glass, etc. They are also used as fertilizer s. They are also used in the production of agar, which is used as a growth medium in microbiological studies. Seaweeds are an important food source, especially in Asia. They are an important source of nutrients such as vitamins A, B1, B2, B6, niacin, and C , iodine, potassium, iron, magnesium, and calcium.
Lotic communities have conditions that are rather harsh for typical plants. Thus, the diversity of plant species in lotic habitats is smaller than in lentic habitats.
Find out why in this tutorial Read More. This tutorial looks at some of the communities in freshwater lentic habitats. For instance, symbiosis occurs in a community of hydrophytes providing a substrate for algae. In return, the algae prevent excessive herbivory of hydrophytes by serving as food to the herbivores. Know more details here Learn about community patterns and the ecological factors influencing these patterns.
Revisit some of the ecosystems you've learned about earlier to learn more about the possible impacts of natural and human-induced environmental changes The movement of molecules specifically, water and solutes is vital to the understanding of plant processes.
This tutorial will be more or less a quick review of the various principles of water motion in reference to plants.
Bryophytes nonvascular plants are a plant group characterized by lacking vascular tissues. They include the mosses, the liverworts, and the hornworts. These groups of plants require external water, usually in the form of dew or rain.
Some of them grow exclusively in dark, damp environments in order to provide moisture. Find out more about them here This tutorial noted some of the physical and chemical factors that provide the framework of a running water community in which organisms in their favored ecological niches occupy.
0コメント