Nostoc

Nostoc is a prokaryotic cyanobacteria that is responsible for performing photosynthesis. They commonly live in colonies in freshwater. In some other instances, they are also found to be living on rocks, attaching themselves to it, or even in the bottom of lakes.

Other areas where nostoc algae are found are in the tree trunks. They are also common as algal components in the lichens. To fungus, they are an endosymbiont. Therefore, students have to study the details cautiously while preparing for their exam.

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Classification of Nostoc

To understand nostoc, let us dig deeper into the same. For building the foundation of understanding nostoc, you have to know the scientific details of it. Scientists have thus classified nostoc in the following manner based on class, phylum, etc.

Students Can Remember This Table to Prepare for Their Exam. It Will also Help You in Framing Answers That Will Fetch You Higher Grades. 

Therefore, you can see that nostoc is classified under the group bacteria. As they are prokaryotic in nature, they do not have the cell membrane to bind the cell organelles. Herein, the genetic materials are simply carried in the cytoplasm.

Structure of Nostoc

Nostoc is a body consisting of many threads like structures, called filament. Each filament structure is composed of many rounded cells that are arranged in a chain like manner. All the cell structures are similar. The whole filament is covered by a sheath made up of polysaccharides and also contains proteins, called a gelatinous sheath. Gelatinous sheath is a protective layer and it absorbs and retains water. The shape of cells are generally, oval, cylindrical or spherical. These mass colonies can be of different size, shape, and color.

To understand the fundamental structure of nostoc, you can refer to the following nostoc diagram. It shows a green color substance, which is round in shape, along with some irregular ones. 

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Now, study the following points so that you can avoid missing out on vital factors regarding nostoc. 

• Nostocs are filamented in nature. In simple words, they have multiple filament-like structures coming out from their body surface. This, in turn, helps in forming colonies. 

• The nostoc cells are generally round or oval in shape. They can also be cylindrical at times.

• Some differentiated cells in nostoc are called heterocysts. These cells specifically aid in nitrogen fixation.

• Colonies formed by nostocs vary based on size, shapes, and colors. They are noticeably greenish, but may also be bluish-green in color. Besides, they are also red-brown or yellow-green in combination.

• The cells of nostoc are thick-walled. These thick walls are due to the presence of peptidoglycan.

• These cells also contain pigments of different kinds. For instance, they have chlorophyll, the green pigment that helps in performing photosynthesis. They also possess a blue pigment called phycocyanin and a red pigment called phycoerythrin.

• The cytoplasm contains cell organelles and even a nucleus. It has the DNA which is void of histones.

Hence, all these features define nostoc. Now that you are aware of its structure make sure you are well-versed with every aspect of the same. For in-depth learning, let us look into some more topics related to nostoc.

Reproduction in Nostoc

Nostoc reproduction happens only in a vegetive and sexual method. The reproduction is performed by the fragmentation. In this process, small colonies will grow by attaching to the large colonies and later on separate from the large one and create their own colonies. Vegetive or Asexual reproduction happens by the formation of resting spores known as akinetes. Nostoc bacteria also reproduce by heterocysts. Heterocysts are differentiated from the filament. Heterocysts divide and germinate into a new filament.

The reproduction in nostoc can be classified into two types, meaning it can reproduce by two different methods. The first one is the asexual method of reproduction. Herein, it forms spores called akinetes and new colonies are created as a result.

Thus, it ends the initial life cycle of nostoc, which is then taken over by the newly formed nostocs. The process is called fragmentation, where small colonies get attached to larger ones. Later, these small colonies separate themselves and grow a new colony.

As already mentioned, nostoc have filaments, which break to form hormogonia. The gelatinous nature of the threads tends to remain even after splitting. After that, it creates new trichomes in the new colony.

Secondly, nostos take help of heterocysts to reproduce. These heterocysts detach themselves from the nostoc and form new filaments. Likewise, a new colony of nostoc is created. 

Significance of Nostocs in Nature

By now, you have known about the structure and characteristics of nostos. All of these combine to describe the importance of nostos in the ecology. However, to make it easier for you to understand, here is a list for the same. 

• Firstly, they contain chlorophyll, which means they are able to produce their own food.

• Secondly, they help in nitrogen fixation, which is why they are planted in paddy fields. 

• Thirdly, they are used as delicacies in certain regions as they are rich in Vitamin C.

• They can produce hydrogen and convert carbon dioxide into biofuels.

• Nostocs can be used for bioremediation of freshwater. They can also degrade the quality of pollutants.

Thus, having discussed these points, it is evident that nostoc is quite a useful aspect in the environment. So, make sure you consider all the points listed above to score better in the exams. 

Nostoc is an integral part of the environment. Herein, you have to know about the structure, reproduction and the entire life cycle of the nostocs. Since each aspect has its challenges while studying, you should be careful in dealing with the same.

Besides, to ensure you do not miss out on any vital topics related to nostoc algae, make notes while you study. Revise them regularly and identify any weaker sections or the ones that are hard to understand. Take professional assistance or seek help from your friends.

Nostoc is called star jelly and a genus of cyanobacteria. Nostoc is found in various environments and surroundings  that are composed of different cells. Nostocs are generally cells that are arranged in a bed-like chain and are always found in a mass group. Nostoc size may differ from a microscopic particle size to a big size. Nostoc can be found on soil and on the floating fresh water. Nostoc can easily be found at the bottom of a lake on moist soil or moist rocks. Nostoc is a type of cyanobacteria that grows in water and helps in fixing the nitrogen from the atmosphere. Nostoc algae can also be found on tree trunks. In lichens also, Nostoc is a common algal component. Nostoc also helps in the process of photosynthesis. Nostoc is one of the most important topics for students preparing for NEET exams. Students should be able to clear all the concepts related to Nostoc because this topic is essential for NEET exam purposes.

Classification of Nostoc

• Domain – Bacteria

• Phylum - Cyanobacteria

• Order - Nostocales

• Family - Nostocaceae

• Genus - Nostoc

Classification of Nostoc starts with, Nostoc first falls under the Domain Bacteria. This is a type of organism with a prokaryotic cell structure with cell walls containing peptidoglycan. This organism has no internal membrane bound structures, or organelles, and the genetic material is not found within a nucleus. Secondly it falls under the Phylum Cyanobacteria that is composed of photosynthetic bacteria. Thirdly, Nostoc then falls into the Order Nostocales because it has non-branching filaments and then further it is separated into the Family Nostocaceae for having special nitrogen fixing heterocysts. Finally, the last stage is the Genus Nostoc, which contains organisms that form spherical colonies of filaments embedded in a gelatinous substance.