Tag: biofertilizers

Questions Related to biofertilizers

Blue-green algae are included in which of the following kingdoms?

  1. Monera

  2. Animalia

  3. Fungi

  4. Both B and C


Correct Option: A
Explanation:

The kingdom monera is comprised of the prokaryotic organisms. The blue-green algae are included under the kingdom monera. These are the primitive form of prokaryotic organisms. They are unicellular or multicellular forming filamentous structures. They do not have well-developed cellular components such as a nuclear membrane, nucleus, mitochondria, etc. 

Thus, the correct answer is option A.

Cynobacteria are:

  1. mosses which attack bacteria.

  2. bacteria which attack cynophyceace

  3. autotrophic organism with phycocyanin

  4. none of these


Correct Option: C
Explanation:

The cyanobacteria (also referred to as blue-green algae) have chlorophyll a similar to green plants and are photosynthetic autotrophs. The cyanobacteria are unicellular, colonial or filamentous, fresh-water marine or terrestrial algae. The colonies are generally surrounded by a gelatinous sheath. They often form blooms in polluted water bodies. Some of these organisms can fix atmospheric nitrogen in specialized cells called heterocysts, e.g, Nostoc and Anabaena.

So the correct option is "autotrophic organisms with phycocyanin".

Biofertilizers are organisms which can bring about soil nutrient enrichment.

  1. True

  2. False


Correct Option: A
Explanation:
Biofertilizers are made of organisms either in living or latent forms which provide the necessary nutrients to the plants .
Hence the statement is true .

Azolla gives a good biofertilizer when mixed with

  1. Bone-meal

  2. Cowdung

  3. Blue-green algae

  4. Urea


Correct Option: C
Explanation:

BGA and Azolla have known to be used for the rice cultivation and they are very good for increasing the crop yield and productivity as they supply the soil and the plant with enough nitrogen. They are known used together as the biofertilizers.


So, the correct option is 'Blue-green algae'

In the beginning there was no oxygen in earth's atmosphere. The activity of which organism is generally supposed to have made the earth's atmosphere aerobic or oxygen-rich?

  1. Monocotyledons

  2. Filamentous algae

  3. Cyanobacteria

  4. Mycoplasma


Correct Option: C
Explanation:

Cyanobacteria also known as Cyanophyta, are a phylum of bacteria that obtain their energy through photosynthesis, and are the only photosynthetic prokaryotes able to produce oxygen. The name "cyanobacteria" comes from the color of the bacteria. Cyanobacteria, which are prokaryotes, are also called "blue-green algae", though the term "algae" in modern usage is restricted to eukaryotes. Phototrophic eukaryotes perform photosynthesis by plastids that may have their ancestry in cyanobacteria, acquired long ago via a process called endosymbiosis. These endosymbiotic cyanobacteria in eukaryotes may have evolved or differentiated into specialized organelles such as chloroplasts, etioplasts and leucoplasts. By producing and releasing oxygen (as a byproduct of photosynthesis), cyanobacteria are thought to have converted the early oxygen-poor, reducing atmosphere into an oxidizing one, causing the Great Oxygenation Event and the "rusting of the Earth", which dramatically changed the composition of the Earth's life forms and led to the near-extinction of anaerobic organisms.

So the correct option is 'cyanobacteria'.

Which of the following plants can act as a biofertilizer

  1. Nostoc

  2. Funaria

  3. Volvox

  4. Rhizopus


Correct Option: A
Explanation:

Nostoc belongs to cyanobacteria genus, and it can be used as biofertilizer. It is also called the blue-green algae. Nostoc converts atmospheric nitrogen into ammonia, which can be further converted to a suitable form for plant growth. Biofertilizers enhance the quality of plants and soil.

So the correct answer is 'Nostoc'.

What is the photosynthetic product in blue-green algae?

  1. Normal starch

  2. Glycogen

  3. Cyanophycean starch resembling glycogen

  4. None of these


Correct Option: C
Explanation:
Blue-green algae, also called cyanobacteria, any of a large, heterogeneous group of prokaryotic, principally photosynthetic organisms. Cyanobacteria resemble the eukaryotic algae in many ways, including morphological characteristics and ecological niches, and were at one time treated as algae, hence the common name of blue-green algae. The process of photosynthesis goes on in cyanobacteria in the same manner as in plants. The storage food products in cyanobacteria are somewhat different from those of green plants. The storage product is usually a starch like substance similar to glycogen and is different from the starch produced in plants. This is known as Cyanophycean starch.

So, the correct answer is 'Cyanophycean starch resembling glycogen'.

Which one of the following are peculiar organisms with non-green slimy, naked mass of protoplasm and many nuclei having characteristics of both plants and animals?

  1. Cyanobacteria

  2. Myxomycetes

  3. Ascomycetes

  4. PPLO


Correct Option: B
Explanation:

Myxomycetes, also called as mycetozoa, phylum of fungus-like organisms within the kingdom protista, commonly known as true slime molds. They exhibit characteristics of both protozoans (one-celled microorganisms) and fungi. Myxomycetes is a class of slime molds, formerly regarded as animals (Mycetozoa), but now generally thought to be plants and often separated as a distinct phylum (Myxophyta); equivalent to the division Myxomycota. They are found on damp earth and decaying vegetable matter and consist of naked masses of protoplasm, which creep very slowly over the surface and ingest solid food.

Which of the following is the pair of biofertilizers?

  1. Azolla and BGA

  2. Nostoc and legume

  3. Rhizobium and grasses

  4. Salmonella and E. coli


Correct Option: A
Explanation:

Biofertilizers are the suspension of microorganism which mainly increases the growth of the plants. These secrete the growth promoting substances. The microorganisms in bio-fertilizers restore the soil's natural nutrient cycle and build soil organic matter. Bio-fertilizers such as Rhizobium, Azotobacter, Azospirilium and blue-green algae (BGA) are used. Anabaena in association with water fern Azolla contributes nitrogen up to 60 kg/ha/season and also enriches soils with organic matter.

So, the correct answer is option A.

Mycorrhiza works as

  1. Modified leaf

  2. Mechanical support

  3. Root hairs in adverse condition

  4. Modified stem


Correct Option: C
Explanation:

Mycorrhiza is the symbiotic relationship between fungi and plant roots in which both gets benefit from each other. Fungus acts as the plant's root hairs and acts as an extension of the root system for more absorption of nutrients and in turn receives carbohydrates (sugars) and growth factors from the plant, Plants with thick roots, poorly branched and with few root hairs, are usually more dependent on mycorrhizae for normal growth and development. Thus, the correct answer is option C.