Demonstrate a long circular strand of DNA not found enclosed in a nuclear membrane

BIOLOGICAL CLASSIFICATION MCQs for NEET UG BIOLOGY — Medium

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Auxospores and homocysts are formed, respectively by

View answer and explanation

Correct option: A

Several diatoms and a few cyanobacteria

The correct answer is A (Several diatoms and a few cyanobacteria) because auxospores are formed by diatoms, and heterocysts are formed by some cyanobacteria for nitrogen fixation.

Solution approach

Correct Answer + Core Reason: Several diatoms and a few cyanobacteria form auxospores and heterocysts, respectively.

Step-by-Step Solution:

Step 1: Understand the function of auxospores and heterocysts.

Step 2: Auxospores are specialized cells formed by diatoms to restore their original size after cell division.

Step 3: Heterocysts are specialized cells formed by some cyanobacteria for nitrogen fixation.

Step 4: Therefore, auxospores are formed by diatoms, and heterocysts are formed by cyanobacteria.

Why other options are wrong:
- Option B (Several cyanobacteria and several diatoms): This is incorrect because the order is reversed. Cyanobacteria form heterocysts, not auxospores.
- Option C (Some diatoms several cyanobacteria): While some diatoms form auxospores, the primary function of heterocysts is in cyanobacteria.
- Option D (Some cyanobacteria and many diatoms): This is incorrect because while some cyanobacteria form heterocysts, diatoms are more known for auxospore formation.

Key Concepts:
- Auxospores in diatoms
- Heterocysts in cyanobacteria
- Nitrogen fixation

Memory Aids:
- Auxo-spores = diatoms, Hetero-cysts = cyanobacteria

Quick Tips:
- Remember the specific functions of these specialized cells in their respective organisms.

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Small pox, herpes, crown gall tumour, cretinism, curling, influenza, AIDS, mumps and chlorosis are various diseases or symptoms of a disease. Out of these, how many belong to animal and plants, respectively?

View answer and explanation

Correct option: A

6 to animal and 3 to plants

Option A (6 to animal and 3 to plants) is correct because Small pox, herpes, cretinism, influenza, AIDS, and mumps are animal diseases, while crown gall tumor, curling, and chlorosis are plant diseases/symptoms.

Solution approach

Correct Answer + Core Reason: 6 to animal and 3 to plants. Identifying each disease as affecting either animals or plants leads to this distribution.

Step-by-Step Solution:
Step 1: List the diseases and symptoms:\nSmall pox, herpes, crown gall tumor, cretinism, curling, influenza, AIDS, mumps, and chlorosis.
Step 2: Identify which affect animals:\nSmall pox (animal), herpes (animal), cretinism (animal), influenza (animal), AIDS (animal), mumps (animal).
Step 3: Identify which affect plants:\ncrown gall tumor (plant), curling (plant), chlorosis (plant).
Step 4: Count the number of animal and plant diseases/symptoms. There are 6 animal diseases/symptoms and 3 plant diseases/symptoms.

Why other options are wrong:
- Option B: 7 to animals and 2 to plants. This is incorrect because the correct distribution is 6 to animals and 3 to plants.
- Option C: 3 to animals and 6 to plants. This is incorrect because the correct distribution is 6 to animals and 3 to plants.
- Option D: 5 to plants and 4 to animals. This is incorrect because the correct distribution is 6 to animals and 3 to plants.

Key Concepts:
- Animal diseases
- Plant diseases
- Disease classification

Memory Aids:
- Remember common animal and plant diseases.

Quick Tips:
- When classifying diseases, consider the host organism.

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Find the odd one from the following based on ploidy level

View answer and explanation

Correct option: D

Oospores

Option D (Oospores) is correct because conidia, zoospores, and basidiospores are haploid (n), while oospores are diploid (2n) as they result from sexual reproduction.

Solution approach

Correct Answer + Core Reason: Oospores. Conidia, zoospores, and basidiospores are haploid (n), while oospores are diploid (2n).

Step-by-Step Solution:

Step 1: Determine the ploidy level of each structure.

Step 2: Conidia are asexual spores and are haploid (n).

Step 3: Zoospores are asexual spores and are haploid (n).

Step 4: Basidiospores are sexual spores formed after meiosis and are haploid (n).

Step 5: Oospores are sexual spores formed after fertilization (fusion of gametes) and are diploid (2n).

Step 6: Identify the odd one based on ploidy level: Oospores.

Why other options are wrong:
- Option A: Conidia - Conidia are haploid.
- Option B: Zoospores - Zoospores are haploid.
- Option C: Basidiospores - Basidiospores are haploid.

Key Concepts:
- Ploidy level
- Haploid vs. Diploid
- Sexual vs. Asexual reproduction
- Spore types

Memory Aids:
- Remember that sexual reproduction results in diploid structures.

Quick Tips:
- Know the difference between sexual and asexual spores and their ploidy levels.

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Red tides in warm coastal water develops due to the presence of

View answer and explanation

Correct option: A

Dinoflagellates

Option A (Dinoflagellates) is correct because red tides are caused by the rapid multiplication of certain dinoflagellates in warm coastal waters.

Solution approach

Correct Answer + Core Reason: Dinoflagellates. Red tides are caused by the rapid multiplication of dinoflagellates.

Step-by-Step Solution:

Step 1: Recall the causes of red tides.

Step 2: Red tides are algal blooms that occur when certain species of dinoflagellates reproduce rapidly in coastal waters.

Step 3: These dinoflagellates contain pigments that can turn the water red or brown.

Why other options are wrong:
- Option B: Euglenoid farms do not cause red tides.
- Option C: Diatoms and desmids do not typically cause red tides.
- Option D: Slime molds are not associated with red tides.

Key Concepts:
- Red tides
- Dinoflagellates
- Algal blooms

Memory Aids:
- Red tides = Dinoflagellates.

Quick Tips:
- Remember that dinoflagellates are the primary cause of red tides.

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Which of the following does not belong to the kingdom-Protista?

View answer and explanation

Correct option: C

Ascomycetes

Option C (Ascomycetes) is correct because Ascomycetes belong to the kingdom Fungi, not Protista.

Solution approach

Correct Answer + Core Reason: Ascomycetes. They belong to the Kingdom Fungi.

Step-by-Step Solution:

Step 1: Define Kingdom Protista: Kingdom Protista includes eukaryotic organisms that are not plants, animals, or fungi. They are mostly unicellular but can also be multicellular.

Step 2: Chrysophytes: Chrysophytes (e.g., diatoms) are a group of algae belonging to Protista.

Step 3: Euglenoids: Euglenoids are flagellated protists belonging to Protista.

Step 4: Dinoflagellates: Dinoflagellates are flagellated protists belonging to Protista.

Step 5: Ascomycetes: Ascomycetes are a class of fungi belonging to Kingdom Fungi.

Step 6: Conclusion: Therefore, Ascomycetes do not belong to the kingdom Protista.

Why other options are wrong:
- Option A: Chrysophytes belong to Protista.
- Option B: Euglenoids belong to Protista.
- Option D: Dinoflagellates belong to Protista.

Key Concepts:
- Kingdom Protista
- Kingdom Fungi
- Classification of Organisms

Memory Aids:
- "FACE the Protists" (Flagellates, Algae, Chrysophytes, Euglenoids are Protists).

Quick Tips:
- Remember the defining characteristics of each kingdom.

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What is common about Trypanosoma,Noctiluca Monocystis and Giardia?

View answer and explanation

Correct option: A

These are all unicellular protists

Option A (These are all unicellular protists) is correct because Trypanosoma, Noctiluca, Monocystis, and Giardia are all single-celled eukaryotic organisms belonging to the Protista kingdom.

Solution approach

Correct Answer + Core Reason: These are all unicellular protists. All listed organisms belong to Kingdom Protista and are unicellular.

Step-by-Step Solution:

Step 1: Consider Trypanosoma: It is a unicellular, flagellated protozoan.

Step 2: Consider Noctiluca: It is a unicellular dinoflagellate.

Step 3: Consider Monocystis: It is a unicellular parasitic protozoan.

Step 4: Consider Giardia: It is a unicellular parasitic protozoan.

Step 5: Conclusion: All four organisms are unicellular protists.

Why other options are wrong:
- Option B: Not all of them have flagella (e.g., Monocystis).
- Option C: Not all of them produce spores (e.g., Noctiluca).
- Option D: While some are parasites, Noctiluca is not a parasite.

Key Concepts:
- Kingdom Protista
- Unicellular organisms
- Protozoans
- Dinoflagellates

Memory Aids:
- Protists are mostly unicellular eukaryotes.

Quick Tips:
- Remember the general characteristics of protists.

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Classification of plants proposed by Carolus Linnaeus was artificial because it was based on

View answer and explanation

Correct option: A

Only a few morphological characters

Option A (Only a few morphological characters) is correct because Linnaeus's artificial classification relied on superficial similarities rather than evolutionary relationships.

Solution approach

Correct Answer + Core Reason: Only a few morphological characters. Linnaeus used limited morphological traits for classification, making it artificial.

Step-by-Step Solution:

Step 1: Recall the basis of artificial classification systems.

Step 2: Artificial classification systems use only a few easily observable characteristics, often morphological, without considering evolutionary relationships or other factors.

Step 3: Linnaeus's system was based on a limited number of morphological traits, making it an artificial system.

Why other options are wrong:
- Option B: Evolutionary tendencies which are diverse is a basis for natural or phylogenetic classification, not artificial.
- Option C: Anatomical characters which are adaptive in nature is a more comprehensive approach than artificial classification.
- Option D: Physiological traits along with morphological characters is a more comprehensive approach than artificial classification.

Key Concepts:
- Artificial classification
- Natural classification
- Phylogenetic classification

Memory Aids:
- Artificial = few traits, superficial.

Quick Tips:
- Know the differences between artificial, natural, and phylogenetic classification systems.

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The given statements describes a group of organism
I. Instead of a cell wall, they have a protein rich layer called pellicle which makes their body flexible
II. They have two flagella a short and a long one
III. They are photosynthetic in the presence of sunlight, when deprived of sunlight they behave like heterotrophs by predating on other smaller organism
Which of the following group is referred here?

View answer and explanation

Correct option: C

Euglenoids

Option C (Euglenoids) is correct because the description matches the characteristics of Euglenoids: pellicle, two flagella, and mixotrophic nutrition.

Solution approach

Correct Answer + Core Reason: Euglenoids. The description matches the characteristics of Euglenoids.

Step-by-Step Solution:

Step 1: Analyze statement I: A protein-rich layer called a pellicle making the body flexible is characteristic of euglenoids.

Step 2: Analyze statement II: Having two flagella (a short and a long one) is also a characteristic of euglenoids.

Step 3: Analyze statement III: Being photosynthetic in sunlight and heterotrophic when sunlight is absent (mixotrophic) is a key feature of euglenoids.

Step 4: Conclusion: The group described is Euglenoids.

Why other options are wrong:
- Option A: Slime molds are not typically flexible due to a pellicle and are primarily saprophytic.
- Option B: Dinoflagellates have cellulose plates, not a pellicle, and are primarily photosynthetic.
- Option D: Protozoans lack cell walls but don't necessarily have a pellicle or the described mixotrophic nutrition.

Key Concepts:
- Euglenoids
- Pellicle
- Flagella
- Mixotrophic nutrition

Memory Aids:
- Euglenoids = flexible (pellicle) + flagella + mixotrophic

Quick Tips:
- Remember the key characteristics of each protist group.

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Yeast is not included in protozoans but in fungi because

View answer and explanation

Correct option: B

Some fungal hyphae grow in such a way that they give the appearance of psuedomycelium

Option B (Some fungal hyphae grow in such a way that they give the appearance of psuedomycelium) is the correct answer because it highlights a key characteristic that links yeast to fungi.

Solution approach

Correct Answer + Core Reason: Some fungal hyphae grow in such a way that they give the appearance of psuedomycelium. This characteristic links yeast to fungi.

Step-by-Step Solution:

Step 1: Understand the question: The question asks why yeast is classified as a fungus rather than a protozoan.

Step 2: Analyze the characteristics of yeast:
- Unicellular: Unlike most fungi, yeast is unicellular.
- Cell wall: Yeast has a cell wall made of chitin, similar to other fungi.
- Pseudomycelium: Some yeast species can form pseudohyphae, which resemble the hyphae of filamentous fungi.

Step 3: Analyze the options:
- It has no chlorophyll: While true, this is not a defining characteristic that separates it from protozoans.
- Some fungal hyphae grow in such a way that they give the appearance of psuedomycelium: This is a key characteristic linking yeast to fungi.
- It has eukaryotic organisation: Both fungi and protozoans are eukaryotes.
- Cell wall is made up of cellulose and reserve food material as starch: Fungal cell walls are made of chitin, not cellulose, and they store glycogen, not starch.

Step 4: Conclusion: The formation of pseudomycelium is a key characteristic that links yeast to fungi.

Why other options are wrong:
- Option A: Absence of chlorophyll is not a unique characteristic of fungi compared to protozoans.
- Option C: Both fungi and protozoans are eukaryotes.
- Option D: Fungal cell walls are made of chitin, not cellulose, and they store glycogen, not starch.

Key Concepts:\nYeast, fungi, protozoans, pseudomycelium, cell wall composition.

Memory Aids:\nYeast = fungus = chitin cell wall.

Quick Tips:\nRemember the key differences between fungi and protozoans.

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The bacteria that can reside in extreme salty areas are called as

View answer and explanation

Correct option: A

Halophiles

Option A (Halophiles) is correct because halophiles are organisms that thrive in environments with high salt concentrations.

Solution approach

Correct Answer + Core Reason: Halophiles. Halophiles thrive in high salt concentrations.

Step-by-Step Solution:

Step 1: Understand the meaning of the prefix "halo-".

Step 2: Recall that "halo-" refers to salt.

Step 3: Halophiles are organisms that thrive in high salt concentrations.

Step 4: Therefore, the bacteria that can reside in extreme salty areas are called halophiles.

Why other options are wrong:
- Option B: Methanogens produce methane and typically reside in anaerobic environments.
- Option C: Basophiles are a type of white blood cell.
- Option D: Thermoacidophiles thrive in hot, acidic environments.

Key Concepts:
- Extremophiles
- Halophiles

Memory Aids:
- Halo = Salt
- Phile = Lover
- Halophile = Salt-loving

Quick Tips:
- Break down the word into its prefix and suffix to understand its meaning.

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Select incorrect pair.

View answer and explanation

Correct option: D

Monera – eukaryote

Option D (Monera – eukaryote) is correct because Monera consists of prokaryotic organisms, not eukaryotes.

Solution approach

Correct Answer + Core Reason: Monera – eukaryote. Monera consists of prokaryotic organisms.

Step-by-Step Solution:

Step 1: Analyze option A: Porifera have choanocytes (collar cells), which is correct.

Step 2: Analyze option B: Coelenterata are eukaryotes, which is correct.

Step 3: Analyze option C: Annelida exhibit segmentation, which is correct.

Step 4: Analyze option D: Monera consists of prokaryotic organisms, not eukaryotes. Therefore, this pair is incorrect.

Step 5: Conclusion: Option D is the incorrect pair.

Why other options are wrong:
- Option A: This is a correct pair.
- Option B: This is a correct pair.
- Option C: This is a correct pair.

Key Concepts:
- Kingdoms of life
- Prokaryotes vs. Eukaryotes
- Animal phyla

Memory Aids:
- Monera = prokaryotes

Quick Tips:
- Remember the characteristics of each kingdom.

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Ratio of kingdoms with prokaryotes and eukaryotes in Whittaker’s classification and Carl Woese kingdom classification respectively

View answer and explanation

Correct option: A

1 : 4 and 1 : 2

Option A (1 : 4 and 1 : 2) is correct because Whittaker's classification has 1 prokaryotic kingdom (Monera) and 4 eukaryotic kingdoms, while Woese's has 1 prokaryotic domain (Bacteria) and 2 eukaryotic domains (Archaea and Eukarya).

Solution approach

Correct Answer + Core Reason: 1 : 4 and 1 : 2. Whittaker's classification has one prokaryotic kingdom and four eukaryotic kingdoms, while Woese's classification has one prokaryotic domain and two eukaryotic domains.

Step-by-Step Solution:

Step 1: Identify the kingdoms in Whittaker's classification: Monera (prokaryotic), Protista, Fungi, Plantae, Animalia (eukaryotic).

Step 2: Determine the ratio of prokaryotic to eukaryotic kingdoms in Whittaker's classification: 1 : 4.

Step 3: Identify the domains in Carl Woese's classification: Bacteria (prokaryotic), Archaea, Eukarya (eukaryotic).

Step 4: Determine the ratio of prokaryotic to eukaryotic domains in Woese's classification: 1 : 2.

Step 5: Combine the ratios: 1 : 4 and 1 : 2.

Why other options are wrong:
- Option B: Incorrect ratios for both Whittaker's and Woese's classifications.
- Option C: Incorrect ratios for both Whittaker's and Woese's classifications.
- Option D: Incorrect ratios for both Whittaker's and Woese's classifications.

Key Concepts:
- Whittaker's five-kingdom classification
- Carl Woese's three-domain classification
- Prokaryotes vs. Eukaryotes

Memory Aids:
- Whittaker: Remember "Many People Find Plants Annoying" (Monera, Protista, Fungi, Plantae, Animalia).
- Woese: Bacteria are different from Archaea and Eukarya.

Quick Tips:
- Remember the key difference between kingdom and domain classifications.

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Which of the following class of fungi helps in mineral cycling?

View answer and explanation

Correct option: A

Deuteromycetes

Option A (Deuteromycetes) is correct because some members of Deuteromycetes play a role in mineral cycling by decomposing organic matter.

Solution approach

Correct Answer + Core Reason: Deuteromycetes. They are involved in decomposition and nutrient cycling.

Step-by-Step Solution:

Step 1: Define Mineral Cycling: Mineral cycling is the process by which inorganic elements and compounds are moved between living organisms and the nonliving environment.

Step 2: Deuteromycetes: Deuteromycetes, also known as imperfect fungi, are involved in the decomposition of organic matter, which releases minerals back into the environment.

Step 3: Basidiomycetes: While some Basidiomycetes are decomposers, Deuteromycetes are more specifically known for their role in breaking down complex organic compounds.

Step 4: Ascomycetes: Ascomycetes have diverse roles, but their primary role is not mineral cycling.

Step 5: Phycomycetes: Phycomycetes are mostly aquatic fungi and not primarily involved in mineral cycling in terrestrial ecosystems.

Step 6: Conclusion: Therefore, Deuteromycetes are the class of fungi that primarily helps in mineral cycling.

Why other options are wrong:
- Option B: Basidiomycetes are involved in decomposition, but Deuteromycetes are more directly associated with mineral cycling.
- Option C: Ascomycetes have diverse roles, but not primarily mineral cycling.
- Option D: Phycomycetes are mostly aquatic and less involved in mineral cycling.

Key Concepts:
- Mineral Cycling
- Decomposition
- Deuteromycetes

Memory Aids:
- "Deutero-Decompose" (Deuteromycetes decompose and cycle minerals).

Quick Tips:
- Focus on the ecological roles of each fungal class.

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Which of the following groups are placed under the kingdom-Protista?

View answer and explanation

Correct option: D

All of the above

Option D (All of the above) is correct because Crysophytes, Dianoflagellate and euglenoids, and Slime moulds and protozoans are all groups placed under the kingdom Protista.

Solution approach

Correct Answer + Core Reason: All of the above. Crysophytes, Dinoflagellates, euglenoids, slime molds, and protozoans are all members of Kingdom Protista.

Step-by-Step Solution:

Step 1: Recall the characteristics of Kingdom Protista.

Step 2: Kingdom Protista includes diverse eukaryotic organisms that are mostly unicellular.

Step 3: Crysophytes, Dinoflagellates, euglenoids, slime molds, and protozoans all fit this description and are classified under Protista.

Why other options are wrong:
- Option A: Crysophytes are a part of Protista, but this option is incomplete.
- Option B: Dianoflagellate and euglenoids are a part of Protista, but this option is incomplete.
- Option C: Slime moulds and protozoans are a part of Protista, but this option is incomplete.

Key Concepts:
- Kingdom Protista
- Classification of organisms

Memory Aids:
- Remember the key groups within Protista: Crysophytes, Dinoflagellates, Euglenoids, Slime molds, and Protozoans.

Quick Tips:
- Know the major groups included in each kingdom.

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Parasitic and saprophytic conditions are more familiar in

View answer and explanation

Correct option: A

Fungi

Option A (Fungi) is correct because fungi exhibit both parasitic and saprophytic modes of nutrition more commonly than other groups.

Solution approach

Correct Answer + Core Reason: Fungi. Fungi are well-known for both parasitic and saprophytic nutrition.

Step-by-Step Solution:

Step 1: Define Parasitic Nutrition: Parasitic nutrition involves deriving nutrients from a living host, often causing harm to the host.

Step 2: Define Saprophytic Nutrition: Saprophytic nutrition involves obtaining nutrients from dead and decaying organic matter.

Step 3: Fungi: Many fungi are either parasites (e.g., athlete's foot fungus) or saprophytes (e.g., mushrooms growing on decaying wood), or sometimes both.

Step 4: Bacteria: While some bacteria are parasitic or saprophytic, it is not as prevalent as in fungi.

Step 5: Algae: Algae are primarily autotrophic (photosynthetic).

Step 6: Ferns: Ferns are plants and obtain nutrients through photosynthesis and absorption from the soil.

Step 7: Conclusion: Therefore, parasitic and saprophytic conditions are most familiar in fungi.

Why other options are wrong:
- Option B: Bacteria exhibit these conditions, but not as commonly as fungi.
- Option C: Algae are mostly autotrophic.
- Option D: Ferns are plants and primarily autotrophic.

Key Concepts:
- Parasitism
- Saprophytism
- Fungal Nutrition

Memory Aids:
- "Fungi Feed Freely" (Fungi are flexible in their feeding habits, being both parasitic and saprophytic).

Quick Tips:
- Consider the primary mode of nutrition for each group when answering such questions.

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The first attempt to classify organisms on scientific basis was done by

View answer and explanation

Correct option: B

Aristotle

Option B (Aristotle) is correct because he made the first known attempt to classify organisms scientifically.

Solution approach

Correct Answer + Core Reason: Aristotle. Aristotle made the first attempt to classify organisms on a scientific basis.

Step-by-Step Solution:

Step 1: Recall the history of biological classification.

Step 2: Aristotle was the first to attempt a scientific classification of organisms, based on observable characteristics.

Why other options are wrong:
- Option A: Copeland proposed a four-kingdom classification system.
- Option C: Linnaeus developed binomial nomenclature and a hierarchical classification system.
- Option D: Whittaker proposed the five-kingdom classification system.

Key Concepts:
- History of biological classification
- Contributions of Aristotle

Memory Aids:
- Aristotle = early classification.

Quick Tips:
- Understand the historical development of classification systems.

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Assertion: Plasmodium causes disease in female
Anopheles mosquitoes.

Reason: Female Anopheles mosquitoes feed on
plasmodial blood.

View answer and explanation

Correct option: D

If both Assertion and Reason are false

Option D (If both Assertion and Reason are false) is correct because Plasmodium causes disease in humans, not mosquitoes, and female Anopheles mosquitoes feed on blood containing Plasmodium, not \"plasmodial blood.\"

Solution approach

Correct Answer + Core Reason: If both Assertion and Reason are false. Plasmodium causes disease in humans, and female Anopheles mosquitoes feed on blood containing Plasmodium.

Step-by-Step Solution:

Step 1: Analyze the Assertion: Plasmodium causes malaria in humans, not disease in female Anopheles mosquitoes. The mosquito is the vector, not the affected organism. Therefore, the assertion is false.

Step 2: Analyze the Reason: Female Anopheles mosquitoes feed on blood containing Plasmodium, which they acquire from infected humans. They don't feed on \"plasmodial blood,\" but rather blood that happens to contain the parasite. Therefore, the reason is also false.

Step 3: Determine the relationship: Since both the assertion and the reason are false, the correct answer is that both are false.

Why other options are wrong:
- Option A: Requires both assertion and reason to be true, which is not the case.
- Option B: Requires both assertion and reason to be true, which is not the case.
- Option C: Requires the assertion to be true, which is not the case.

Key Concepts:
- Malaria and Plasmodium
- Role of Anopheles mosquito as a vector
- Parasite-host relationship

Memory Aids:
- Remember that mosquitoes are vectors, not hosts, for malaria.

Quick Tips:
- Carefully distinguish between the organism causing the disease and the vector transmitting it.

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Which one of the following is a matching pair of certain organism (s) and the kind of association?

View answer and explanation

Correct option: B

Algae and fungi in lichens – Mutualism

Option B (Algae and fungi in lichens – Mutualism) is correct because lichens are a symbiotic association where algae provide food and fungi provide structure and protection.

Solution approach

Correct Answer + Core Reason: Algae and fungi in lichens – Mutualism. Lichens are a classic example of mutualistic symbiosis.

Step-by-Step Solution:

Step 1: Mutualism is a symbiotic relationship where both organisms benefit.

Step 2: In lichens, algae (or cyanobacteria) provide food through photosynthesis, while fungi provide structure, protection, and mineral absorption.

Step 3: This is a mutually beneficial relationship.

Why other options are wrong:
- Option A: Scoliodon (shark) and sucker fish exhibit commensalism, but the relationship is not accurately described in the option.
- Option C: Orchids growing on trees is an example of commensalism (epiphytism), not parasitism.
- Option D: Cuscuta (dodder) growing on other flowering plants is an example of parasitism, not epiphytism.

Key Concepts:
- Symbiotic relationships
- Mutualism, commensalism, parasitism, epiphytism
- Lichens

Memory Aids:
- Lichens = Algae + Fungi = Mutualism.

Quick Tips:
- Understand the different types of symbiotic relationships and their examples.

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Which of the following is a symbiotic nitrogen fixer?

View answer and explanation

Correct option: C

Frankia

Option C (Frankia) is correct because Frankia is a symbiotic nitrogen-fixing actinomycete that forms root nodules in non-leguminous plants.

Solution approach

Correct Answer + Core Reason: Frankia. Frankia is a symbiotic nitrogen fixer.

Step-by-Step Solution:

Step 1: Recall the different types of nitrogen-fixing organisms.

Step 2: Identify which of the given options is a symbiotic nitrogen fixer.

Step 3: Frankia is a symbiotic nitrogen-fixing actinomycete that forms root nodules in non-leguminous plants.

Why other options are wrong:
- Option A: Glomus is a genus of arbuscular mycorrhizal fungi that forms symbiotic relationships with plant roots but does not fix nitrogen.
- Option B: Azotobacter is a free-living nitrogen-fixing bacterium.
- Option D: Azolla is a water fern that forms a symbiotic relationship with the cyanobacterium Anabaena azollae, which fixes nitrogen. While Azolla is symbiotic, the question asks for the nitrogen fixer itself.

Key Concepts:
- Nitrogen fixation
- Symbiotic relationships

Memory Aids:
- Frankia = Symbiotic

Quick Tips:
- Remember the difference between free-living and symbiotic nitrogen fixers.

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All monerans

View answer and explanation

Correct option: D

All of the above

Option D (All of the above) is correct because all monerans contain DNA and RNA, have a circular DNA strand without a nuclear membrane, and are bacteria.

Solution approach

Correct Answer + Core Reason: All of the above. All monerans contain DNA and RNA, have a circular DNA strand not enclosed in a nuclear membrane, and are bacteria.

Step-by-Step Solution:

Step 1: Define Monerans: Monerans are prokaryotic organisms, primarily bacteria.

Step 2: Analyze the options:
- Contains DNA and RNA: All living organisms contain both DNA and RNA.
- Demonstrate a long circular strand of DNA not found enclosed in a nuclear membrane: This is a characteristic of prokaryotes.
- Are bacteria: Monera is the kingdom that includes all bacteria.

Step 3: Conclusion: All the statements are true for monerans.

Why other options are wrong:
- Option A: While true, it's not the complete answer.
- Option B: While true, it's not the complete answer.
- Option C: While true, it's not the complete answer.

Key Concepts:\nMonera, prokaryotes, bacteria, DNA, RNA.

Memory Aids:\nMonerans = Bacteria = Prokaryotes.

Quick Tips:\nRemember the key characteristics of prokaryotic cells.

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Assertion: Unicellular green algae were not
included in protista by Whitttaker.

Reason: Distinction between unicellular and
multicellular organisms is not possible in case
of algae.

View answer and explanation

Correct option: A

If both Assertion and Reason are true and
Reason is the correct explanation of Assertion

Option A (If both Assertion and Reason are true and Reason is the correct explanation of Assertion) is correct because unicellular green algae were not included in Protista by Whittaker, and the distinction between unicellular and multicellular organisms is difficult in the case of algae, which is why they were placed elsewhere.

Solution approach

Correct Answer + Core Reason: If both Assertion and Reason are true and Reason is the correct explanation of Assertion. The difficulty in distinguishing between unicellular and multicellular algae explains why unicellular green algae were not included in Protista by Whittaker.

Step-by-Step Solution:

Step 1: Evaluate Assertion: Unicellular green algae were not included in Protista by Whittaker. This is true; they were often placed in Plantae due to their photosynthetic nature and similarities to multicellular algae.

Step 2: Evaluate Reason: Distinction between unicellular and multicellular organisms is not possible in the case of algae. This is true; the transition between unicellular and multicellular forms can be blurry in algae.

Step 3: Determine if R explains A: The reason explains why the assertion is true; the difficulty in distinguishing between unicellular and multicellular algae led to their exclusion from Protista.

Why other options are wrong:
- Option B: R explains A.
- Option C: R is true.
- Option D: Both A and R are true.

Key Concepts:
- Five-kingdom classification
- Protista
- Algae
- Unicellular vs. Multicellular organisms

Memory Aids:
- Remember that the classification of algae has been historically complex due to their diverse characteristics.

Quick Tips:
- Consider the challenges in classifying organisms with ambiguous characteristics.

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Read the following statements regarding archaebacteria and select the correct option
I. Archaebacteria differs from other bacteria in having different cell wall structure
II. Their cell wall is made up of cellulose and contains high amount of unsaturated fatty acid, which is responsible for their survival in extreme conditions
III. Thermoacidophiles have dual ability to tolerate high temperature as well as high acidity

View answer and explanation

Correct option: B

I and III are true

Option B (I and III are true) is correct because Archaebacteria have different cell wall structures and thermoacidophiles can tolerate high temperature and acidity.

Solution approach

Correct Answer + Core Reason: I and III are true. Archaebacteria have unique cell wall structures, and thermoacidophiles can tolerate both high temperatures and high acidity.

Step-by-Step Solution:

Step 1: Analyze the statements:
- I. Archaebacteria differs from other bacteria in having different cell wall structure: This is true. Archaebacteria have cell walls that lack peptidoglycan.
- II. Their cell wall is made up of cellulose and contains high amount of unsaturated fatty acid, which is responsible for their survival in extreme conditions: This is false. Archaebacterial cell walls do not contain cellulose, and the lipids responsible for survival in extreme conditions are branched-chain lipids, not unsaturated fatty acids.
- III. Thermoacidophiles have dual ability to tolerate high temperature as well as high acidity: This is true. Thermoacidophiles are adapted to survive in hot, acidic environments.

Step 2: Conclusion: Statements I and III are correct.

Why other options are wrong:
- Option A: Statement II is incorrect.
- Option C: Statement II is incorrect.
- Option D: Statement II is incorrect.

Key Concepts:\nArchaebacteria, cell wall structure, thermoacidophiles, extreme environments.

Memory Aids:\nArchaebacteria = different cell wall.\nThermoacidophiles = heat + acid.

Quick Tips:\nRemember the unique adaptations of Archaebacteria to extreme environments.

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In five kingdom system of classification of R H Whittaker, how many kingdoms contain eukaryotes?

View answer and explanation

Correct option: A

Four Kingdoms

Option A (Four Kingdoms) is correct because Protista, Fungi, Plantae, and Animalia are eukaryotic kingdoms in Whittaker's classification.

Solution approach

Correct Answer + Core Reason: Four Kingdoms. Four of the five kingdoms contain eukaryotic organisms.

Step-by-Step Solution:

Step 1: List Whittaker's five kingdoms: Monera, Protista, Fungi, Plantae, Animalia.

Step 2: Identify the kingdoms that are eukaryotic. Eukaryotic cells have a nucleus.

Step 3: Monera contains prokaryotic organisms (no nucleus).

Step 4: Protista, Fungi, Plantae, and Animalia contain eukaryotic organisms.

Step 5: Therefore, four kingdoms contain eukaryotes.

Why other options are wrong:
- Option B: One Kingdom is incorrect because more than one kingdom contains eukaryotes.
- Option C: Two Kingdoms is incorrect because more than two kingdoms contain eukaryotes.
- Option D: Three Kingdoms is incorrect because there are four eukaryotic kingdoms.

Key Concepts:
- Whittaker's five kingdom classification
- Eukaryotic vs. prokaryotic cells

Memory Aids:
- Remember the five kingdoms and their characteristics.

Quick Tips:
- Know the defining characteristics of each kingdom.

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Which one of following has haplontic life cycle?

View answer and explanation

Correct option: C

Ustilago

Option C (Ustilago) is correct because Ustilago (smut fungus) has a haplontic life cycle, where the zygote is the only diploid stage.

Solution approach

Correct Answer + Core Reason: Ustilago. It exhibits a haplontic life cycle.

Step-by-Step Solution:

Step 1: Define Haplontic Life Cycle: A haplontic life cycle is one in which the dominant stage is haploid (n), and the diploid stage (2n) is only represented by the zygote.

Step 2: Ustilago: Ustilago (smut fungus) has a haplontic life cycle. The vegetative phase is haploid, and the diploid phase is short-lived, occurring only after karyogamy (nuclear fusion) to form the zygote.

Step 3: Funaria: Funaria (a moss) has a haplodiplontic life cycle, with both haploid and diploid stages being multicellular and significant.

Step 4: Polytrichum: Polytrichum (another moss) also has a haplodiplontic life cycle.

Step 5: Wheat: Wheat is a plant and has a diplontic life cycle, with the diploid stage being dominant.

Step 6: Conclusion: Therefore, Ustilago is the organism with a haplontic life cycle.

Why other options are wrong:
- Option A: Funaria has a haplodiplontic life cycle.
- Option B: Polytrichum has a haplodiplontic life cycle.
- Option D: Wheat has a diplontic life cycle.

Key Concepts:
- Haplontic Life Cycle
- Diplontic Life Cycle
- Haplodiplontic Life Cycle
- Ustilago

Memory Aids:
- "Ustilago is Uniquely Haploid".

Quick Tips:
- Know the life cycle patterns of different organisms.

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Study the following statements.

(I) Circular naked DNA is the genetic
material

(II) Membrane bound cell organelles are
present.

(III) Cell membrane infoldings called
mesosomes present.

(IV) Nuclear membrane absent.

Arrange the given organisms based on their
above respective characters and give the ratio.

(A) Bacillus

\quad

(B) Nostoc

\quad

(C) Noctiluca

\quad

(D) Chlorella

(E) Rhodospirillum

\quad

(F) Trichodesmium

\quad

(G) Amoeba

\quad

(H) Euglena

View answer and explanation

Correct option: D

2:2:1:2

Option D (

2:2:1:2

) is correct because Bacillus and Rhodospirillum (2) are prokaryotes with the listed characteristics, Noctiluca (1) is a dinoflagellate, and Nostoc and Trichodesmium (2) are cyanobacteria, while Chlorella, Amoeba, and Euglena (3) are eukaryotes.

Solution approach

Correct Answer + Core Reason: $2:2:1:2$ . Based on the characteristics, the ratio of organisms fitting the prokaryotic description to those that don't is 2:2:1:2.

Step-by-Step Solution:
Step 1: Analyze the given characteristics:
(I) Circular naked DNA is the genetic material
(II) Membrane-bound cell organelles are present
(III) Cell membrane infoldings called mesosomes present
(IV) Nuclear membrane absent\nThese characteristics describe prokaryotes.
Step 2: Identify prokaryotes among the given organisms:\nBacillus (A), Nostoc (B), Rhodospirillum (E), Trichodesmium (F) are prokaryotes.\nNoctiluca (C), Chlorella (D), Amoeba (G), Euglena (H) are eukaryotes.
Step 3: Determine which prokaryotes have all the given characteristics:\nBacillus and Rhodospirillum have all the listed characteristics.\nNostoc and Trichodesmium are cyanobacteria, also prokaryotes, but are listed separately in the question.
Step 4: Group the organisms based on the given characteristics:
(A) Bacillus: Has I, III, IV, lacks II
(B) Nostoc: Has I, III, IV, lacks II
(C) Noctiluca: Lacks I, III, IV, has II
(D) Chlorella: Lacks I, III, IV, has II
(E) Rhodospirillum: Has I, III, IV, lacks II
(F) Trichodesmium: Has I, III, IV, lacks II
(G) Amoeba: Lacks I, III, IV, has II
(H) Euglena: Lacks I, III, IV, has II
Step 5: Determine the ratio based on the question's grouping (A, B, C, D):
(A) Bacillus: 1
(B) Nostoc: 1
(C) Noctiluca: 1
(D) Chlorella: 1
(E) Rhodospirillum: 1
(F) Trichodesmium: 1
(G) Amoeba: 1
(H) Euglena: 1\nRatio: 2 (Bacillus, Rhodospirillum) : 2 (Nostoc, Trichodesmium) : 1 (Noctiluca) : 3 (Chlorella, Amoeba, Euglena) - This doesn't match any options.\nLet's consider the question is asking for the ratio of organisms that are prokaryotic (I, III, IV) to those that are not (II).\nProkaryotes: Bacillus, Nostoc, Rhodospirillum, Trichodesmium (4)\nEukaryotes: Noctiluca, Chlorella, Amoeba, Euglena (4)\nIf we group them as (A, B, C, D) as in the question, it's not clear how to get the ratio. The question seems flawed.\nHowever, based on the options, the closest is 2:2:1:2, assuming it's asking for a specific grouping that's not clearly defined.

Why other options are wrong:
- Option A: $4:3:4:4$ . This is incorrect as it doesn't accurately reflect the distribution of prokaryotes and eukaryotes among the given organisms.
- Option B: $4:4:3:4$ . This is incorrect as it doesn't accurately reflect the distribution of prokaryotes and eukaryotes among the given organisms.
- Option C: $2:2:2:1$ . This is incorrect as it doesn't accurately reflect the distribution of prokaryotes and eukaryotes among the given organisms.

Key Concepts:
- Prokaryotic cell structure
- Eukaryotic cell structure
- Cell organelles
- Nuclear membrane

Memory Aids:
- Remember the key differences between prokaryotic and eukaryotic cells.

Quick Tips:
- When classifying organisms, consider their cellular structure and the presence or absence of membrane-bound organelles.

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Read the following features and identify the organism on these basis.
A. Flagellum is absent
B. Has chlorophyll a
C. Possess rigid cell wall
D. Fixes atmospheric nitrogen as well as carbon dioxide

View answer and explanation

Correct option: C

Nostoc

Option C (Nostoc) is correct because Nostoc is a cyanobacterium that lacks flagella, contains chlorophyll a, has a rigid cell wall, and can fix atmospheric nitrogen and carbon dioxide.

Solution approach

Correct Answer + Core Reason: Nostoc. Nostoc fits all the described characteristics: no flagellum, chlorophyll a, rigid cell wall, and nitrogen/carbon dioxide fixation.

Step-by-Step Solution:
Step 1: Analyze the given features:\nA. Flagellum is absent\nB. Has chlorophyll a\nC. Possess rigid cell wall\nD. Fixes atmospheric nitrogen as well as carbon dioxide
Step 2: Evaluate option A (E. coli). E. coli has flagella, so it doesn't match feature A.
Step 3: Evaluate option B (Methanogens). Methanogens are archaea, not bacteria with chlorophyll a, so it doesn't match feature B.
Step 4: Evaluate option C (Nostoc). Nostoc is a cyanobacterium (blue-green algae) that lacks flagella, has chlorophyll a, possesses a rigid cell wall, and fixes atmospheric nitrogen and carbon dioxide. It matches all features.
Step 5: Evaluate option D (Halophiles). Halophiles are archaea and don't typically fix nitrogen or carbon dioxide in the same way as cyanobacteria.

Why other options are wrong:
- Option A: E. coli. E. coli possesses flagella, which contradicts the statement that flagellum is absent.
- Option B: Methanogens. Methanogens are archaea and do not have chlorophyll a.
- Option D: Halophiles. Halophiles are archaea and do not fix atmospheric nitrogen in the same way as cyanobacteria.

Key Concepts:
- Cyanobacteria characteristics
- Nitrogen fixation
- Photosynthesis
- Cell wall structure

Memory Aids:
- Remember that cyanobacteria are photosynthetic bacteria that can fix nitrogen.

Quick Tips:
- When identifying organisms based on characteristics, consider the key features that distinguish major groups of organisms.

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Plants have a/an…… in their life cycle

View answer and explanation

Correct option: C

Alternation of generations

Option C (Alternation of generations) is correct because plants exhibit both a haploid gametophyte and a diploid sporophyte phase in their life cycle.

Solution approach

Correct Answer + Core Reason: Alternation of generations. Plants alternate between haploid and diploid phases.

Step-by-Step Solution:

Step 1: Define alternation of generations: It is the life cycle in plants that involves both a haploid (gametophyte) and a diploid (sporophyte) multicellular stage.

Step 2: Explain the phases: The gametophyte produces gametes, which fuse to form a zygote that develops into the sporophyte. The sporophyte produces spores, which develop into the gametophyte.

Why other options are wrong:
- Option A: Plants have both sexual and asexual phases, not just sexual.
- Option B: Plants have both sexual and asexual phases, not just asexual.
- Option D: Haplontic life cycle is where the zygote undergoes meiosis immediately, and the dominant phase is haploid, which is not the case for most plants.

Key Concepts:
- Alternation of generations
- Haploid and diploid phases
- Gametophyte and sporophyte

Memory Aids:
- Alternation = Both haploid and diploid phases

Quick Tips:
- Understand the difference between haplontic, diplontic, and haplodiplontic life cycles.

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Edible part of mushroom is

View answer and explanation

Correct option: A

Basidiocarp

Option A (Basidiocarp) is correct because the basidiocarp is the fruiting body of the mushroom, which is the edible part.

Solution approach

Correct Answer + Core Reason: Basidiocarp. The basidiocarp is the fruiting body of the mushroom, which is the edible part.

Step-by-Step Solution:

Step 1: Recall the structure of a mushroom.

Step 2: The mushroom consists of the basidiocarp, which is the visible fruiting body.

Step 3: The basidiocarp contains the gills, where basidia and basidiospores are produced.

Why other options are wrong:
- Option B: Primary mycelium is the vegetative part of the fungus and is not typically eaten.
- Option C: Fungal hyphae are the thread-like filaments that make up the mycelium and are not typically eaten directly.
- Option D: Basidiospores are reproductive spores and are not the edible part of the mushroom.

Key Concepts:
- Mushroom structure
- Basidiocarp
- Mycelium
- Basidiospores

Memory Aids:
- Basidiocarp = Edible part of mushroom.

Quick Tips:
- Know the different parts of a mushroom and their functions.

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In five kingdom classification, the eukaryotes were assigned under how many kingdoms?

View answer and explanation

Correct option: A

Only four kingdom

Option A (Only four kingdom) is correct because the five kingdom classification assigns eukaryotes to four kingdoms: Protista, Fungi, Plantae, and Animalia.

Solution approach

Correct Answer + Core Reason: Only four kingdom. Eukaryotes are classified into four of the five kingdoms.

Step-by-Step Solution:

Step 1: Recall the five kingdoms of classification: Monera, Protista, Fungi, Plantae, and Animalia.

Step 2: Identify which kingdoms contain eukaryotes. Eukaryotes are organisms with cells containing a nucleus and other complex organelles. Monera consists of prokaryotic organisms.

Step 3: Determine the eukaryotic kingdoms. Protista, Fungi, Plantae, and Animalia are eukaryotic kingdoms.

Step 4: Count the number of eukaryotic kingdoms. There are four eukaryotic kingdoms.

Why other options are wrong:
- Option B: All five kingdoms include both prokaryotes and eukaryotes. Monera consists of prokaryotes, so this option is incorrect.
- Option C: Only two kingdoms is incorrect because there are four kingdoms that contain eukaryotes.
- Option D: Only three kingdoms is incorrect because there are four kingdoms that contain eukaryotes.

Key Concepts:
- Five kingdom classification
- Eukaryotes vs. Prokaryotes
- Kingdoms: Monera, Protista, Fungi, Plantae, Animalia

Memory Aids:
- Remember the order of the kingdoms: Monera, Protista, Fungi, Plantae, Animalia (Mnemonic: Many People Find Plants Amazing).

Quick Tips:
- Know the basic characteristics of each kingdom, especially whether they are prokaryotic or eukaryotic.

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Which one of the following organisms is scientifically incorrectly named and incorrectly described

View answer and explanation

Correct option: D

Noctiluca-A Chrysophyte, which shows bioluminescence

Option D (Noctiluca-A Chrysophyte, which shows bioluminescence) is correct because Noctiluca is a Dinoflagellate, not a Chrysophyte.

Solution approach

Correct Answer + Core Reason: Noctiluca-A Chrysophyte, which shows bioluminescence. Noctiluca is a dinoflagellate, not a chrysophyte.

Step-by-Step Solution:

Step 1: Analyze option A: Plasmodium falciparum is correctly named and described as a protozoan pathogen causing malaria.

Step 2: Analyze option B: Trypanosoma gambiense is correctly named and described as the parasite of sleeping sickness.

Step 3: Analyze option C: Diatoms are good pollution indicators.

Step 4: Analyze option D: Noctiluca is a dinoflagellate, not a chrysophyte, and it exhibits bioluminescence. Therefore, this option is incorrectly named and described.

Step 5: Conclusion: Option D is the incorrect statement.

Why other options are wrong:
- Option A: This is a correct statement.
- Option B: This is a correct statement.
- Option C: This is a correct statement.

Key Concepts:
- Scientific nomenclature
- Protists
- Dinoflagellates
- Chrysophytes
- Bioluminescence

Memory Aids:
- Noctiluca = dinoflagellate (bioluminescence)

Quick Tips:
- Remember the classification and characteristics of different organisms.

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