Kingdom Monera MCQ Quiz - Objective Question with Answer for Kingdom Monera - Download Free PDF

The correct answer is a and d

Explanation:

• a. True: Chemosynthetic bacteria play a significant role in recycling nutrients such as nitrogen, phosphorus, iron, and sulfur by converting these elements into forms that can be utilized by other organisms in the environment.
• b. False: Chemosynthetic bacteria are not heterotrophic bacteria. They are autotrophic bacteria that produce their own food using energy derived from the oxidation of inorganic substances, such as ammonia or sulfur compounds, rather than relying on organic substances.
• c. False: Chemosynthetic bacteria release energy by oxidizing inorganic substances, not organic substances. This oxidation process provides the energy required to produce organic molecules from carbon dioxide (CO₂).
• d. True: Chemosynthetic bacteria are crucial in nutrient cycling, as they help in the conversion and recycling of essential nutrients within ecosystems, maintaining ecological balance.

Therefore, the true statements are a and d.

The correct answer is C only

Explanation:

• Statement A is correct: Bacteria are the sole members of the Kingdom Monera. They are the most abundant micro-organisms. soil. They also live in extreme habitats such as hot springs, deserts, snow and deep oceans where very few other life forms can survive.
• Statement B is correct: Bacteria primarily reproduce by binary fission, a type of asexual reproduction where a single bacterial cell divides into two identical daughter cells.
• Statement C is incorrect: Bacteria are generally considered to be simple in structure but can exhibit complex behavior. Their cellular structure is less complex compared to eukaryotic cells, as they lack membrane-bound organelles and a well-defined nucleus. However, their behavior, including metabolic diversity, ecological roles, and genetic exchange, can be quite complex.
• Statement D is correct: Bacteria can be photosynthetic autotrophic (those that perform photosynthesis to produce their own food) or chemosynthetic autotrophic (those that obtain energy by oxidizing inorganic substances).

Therefore, the incorrect statement is C only.

The correct option is:3

Explanation:

• Option A (Amphitrichous bacteria have flagella at only one pole): Incorrect. Amphitrichous bacteria have a single flagellum at each pole, not just one pole.

• Option B (Lophotrichous bacteria are non-motile): Incorrect. Lophotrichous bacteria have a cluster of flagella at one or both poles, enabling them to move effectively. They are motile.

• Option C (Peritrichous bacteria show random motion): Correct. Peritrichous bacteria have flagella distributed all over their surface. These flagella facilitate random movement, often involving a "run-and-tumble" mechanism that allows them to explore their environment.

• Option D (Monotrichous bacteria lack flagella): Incorrect. Monotrichous bacteria have a single flagellum at one pole, enabling directional motility. They do not lack flagella.

 Key Points

• Flagellar Arrangements:
  • Monotrichous: A single flagellum at one pole (e.g., Vibrio cholerae).
  • Amphitrichous: A single flagellum at both poles (e.g., Spirillum).
  • Lophotrichous: A cluster of flagella at one or both poles (e.g., Pseudomonas).
  • Peritrichous: Flagella distributed over the entire surface (e.g., Escherichia coli).

The correct answer is Statement 1 is correct, and Statement 2 is incorrect.

Explanation:

• The kingdom Monera consists of prokaryotic organisms, which include bacteria and cyanobacteria (blue-green algae).
• Prokaryotic organisms do not have a well-defined nucleus; instead, their genetic material is found in the nucleoid region within the cell.
  • Statement 1 is correct: Monera consists of prokaryotic organisms like bacteria and cyanobacteria. These organisms lack true nuclei and membrane-bound organelles, and they are among the simplest forms of life.
  • Statement 2 is incorrect: Members of the kingdom Monera do not have a well-defined nucleus. Their genetic material is not enclosed within a nuclear membrane, which is a characteristic feature of eukaryotic cells, not prokaryotic cells.

Therefore, Statement 1 is correct, and Statement 2 is incorrect.

The correct answer is:3

Explanation:

• Exotoxins are proteins secreted by certain bacteria that can trigger a strong immune response in the host. These toxins are often highly specific in their action, affecting various cells and tissues, and they can cause severe damage to the host organism. Exotoxins are classified as virulence factors and can be recognized by the immune system as harmful, triggering an immune response.
• Exotoxins are actively secreted by bacteria (e.g., Clostridium botulinum, Staphylococcus aureus) and often cause symptoms of disease such as diarrhea, paralysis, or tissue damage.
• They are distinct from endotoxins, which are components of the bacterial cell wall, such as lipopolysaccharides (LPS), and only trigger an immune response when the bacteria are lysed or die.

Key Points

• Peptidoglycan of Gram-positive bacteria: This is part of the bacterial cell wall and can trigger an immune response, but it is classified as a PAMP (pathogen-associated molecular pattern), not an exotoxin.
• Lipopolysaccharide (LPS): LPS is a component of the outer membrane of Gram-negative bacteria and acts as an endotoxin, not an exotoxin. It also triggers immune responses but in a different way than exotoxins.
• Capsule of Gram-negative bacteria: The capsule helps bacteria evade the immune system but does not trigger an immune response directly, nor is it classified as an exotoxin.

Key Points

• In bacteria, there are three different types of processes for the transfer of genetic information.
• These are namely Conjugation, Transduction and Transformation.
• Conjugation is the method of transfer of genetic material from one bacteria to another through a conjugation tube or by cell to cell in contact.
• This method was proposed by Lederberg and Tatum in E. coli.
• They discovered that the F-factor can move between E. coli cells and the concept of conjugation was put forth.
• The steps of Conjugation include:
  • Formation of the Pilus and the mating pair
  • Conjugal DNA synthesis
  • DNA transfer
  • Maturation

Explanation:

• Conjugation between F+ (donor) and F- (recipient) strains always yields an F+ strain.
• The F+ cells (donor) form a sex pilus and the donor cell pulls itself close to the recipient using pilus.
• The sex pilus forms a conjugation tube and facilitates direct contact between the donor and the recipient cells.
• DNA is transferred between cells during the starting of conjugation.
• The F+ cells contain both chromosomal DNA and F-plasmid.
• F- factor is known as fertility factor which is a chunk of DNA found in donor cells.
• The F-factor opens at the origin of replication.
• One strand is cut at the origin of replication, and the 5’ end enters the recipient cell.
• The F factor transfers from the F+ cells to the F- cells and the recipient cell turns into an F+ strain.
• The recipient cell now contains a copy of the F plasmid and becomes a donor cell.

Hence, the correct option is (1) F+ strain.

Concept:

• According to R.H. Whittaker's Five Kingdom system, all types of bacteria are placed in Kingdom Monera.
• Kingdom Monera thus includes unicellular prokaryotic organisms. Eg: Cyanobacteria
• Kingdom Monera is classified into two groups based on evolution: Archaebacteria and Eubacteria.

Important Points

• Option 1: Eubacteria - Peptidoglycan
  • ​This correlation is correctly matched.
  • The cell wall of eubacteria is made up of peptidoglycan.
  • Peptidoglycan also known as murein is found in only bacterial cells.
  • It provides rigidity to the cell wall.
• Option 2: Sulphur bacteria - Thermoacidophile 
  • This correlation is correctly matched.
  • The bacteria that can thrive in extremely hot and acidic areas are grouped under thermoacidophiles.
  • pH levels in these areas are generally less than 4. Temperatures are greater than 55°C.
  • Hot springs are one such area where thermoacidophiles can survive.
  • Thermoplasma is an example of a thermoacidophile.
  • Thermoplasma is found in acidic sulfur springs. In anaerobic respiration, the prokaryote is dependent on sulfur respiration.
• Option 3: Thermophile - Hot springs
  • ​This correlation is correctly matched.
  • Thermophiles are heat-loving organisms.
  • These organisms show optimal growth at higher temperatures - above 60°C.
  • Thermophiles are found in habitats with extreme conditions such as hot springs, hydrothermal vents, volcanic sites, etc.
  • Most thermophiles are archaebacteria.
  • Methanopyrus kandleri is a thermophile.
• Option 4: Dead sea - Methanogens ​
  • This correlation is mismatched.
  • Methanogens are a group of bacteria that are found in the gut of ruminants like cows.
  • They produce methane as a metabolic by-product.
  • Methanosaeta concilii is an example of methanogen.
  • Organisms that are found in the Dead sea withstand high salinities.
  • These organisms are referred to as halophiles.
  • Haloferax volcanii is an example of a halophile.

So the correct answer is option 4.

Key Points

• Bacteria are the sole members of the Kingdom Monera and they are the most abundant microorganisms.
• These can live in extreme habitats such as hot springs, deserts, snow, and deep oceans, where very few other life forms can survive.
• Some of the bacteria are autotrophic, i.e. they can synthesize their own food from inorganic substances.
• They are either photosynthetic autotrophic or chemosynthetic autotrophic.
• Bacteria are heterotrophs also and they do not synthesize their own food but depend on other organisms or on dead organic matter for food.

Explanation:

• Photoautotrophic bacteria trap light energy and convert it into chemical energy and make their own food like plants. 
• Photoautotrophic bacteria may carry out either oxygenic photosynthesis or anoxygenic photosynthesis.
• Oxygenic Photosynthetic bacteria use H₂O as an electron donor and oxygen is produced in the reaction. e.g., cyanobacteria.
• The majority of photosynthetic bacteria are anoxygenic, as they lack the ability to use water as an electron donor.
• Instead of H₂O, anoxygenic bacteria use H₂S, H₂, or thiosulphate as reducing agents and hydrogen sources.
• The schematic presentation of anoxygenic photosynthesis -​

CO₂ + 2H₂S + light energy → [CH₂O] + 2S + H₂O

• Anoxygenic means they cannot split H₂O, so no oxygen is evolved.
• They possess a photosynthetic pigment known as bacteriochlorophyll.
• Examples of anoxygenic bacteria are green sulfur bacteria, purple sulfur bacteria, purple non-sulfur bacteria, phototrophic acidobacteria, heliobacteria, and FAPs (filamentous anoxygenic phototrophs).

Hence, the correct option is (1).

The correct answer is a and d

Explanation:

• a. True: Chemosynthetic bacteria play a significant role in recycling nutrients such as nitrogen, phosphorus, iron, and sulfur by converting these elements into forms that can be utilized by other organisms in the environment.
• b. False: Chemosynthetic bacteria are not heterotrophic bacteria. They are autotrophic bacteria that produce their own food using energy derived from the oxidation of inorganic substances, such as ammonia or sulfur compounds, rather than relying on organic substances.
• c. False: Chemosynthetic bacteria release energy by oxidizing inorganic substances, not organic substances. This oxidation process provides the energy required to produce organic molecules from carbon dioxide (CO₂).
• d. True: Chemosynthetic bacteria are crucial in nutrient cycling, as they help in the conversion and recycling of essential nutrients within ecosystems, maintaining ecological balance.

Therefore, the true statements are a and d.

The correct answer is C only

Explanation:

• Statement A is correct: Bacteria are the sole members of the Kingdom Monera. They are the most abundant micro-organisms. soil. They also live in extreme habitats such as hot springs, deserts, snow and deep oceans where very few other life forms can survive.
• Statement B is correct: Bacteria primarily reproduce by binary fission, a type of asexual reproduction where a single bacterial cell divides into two identical daughter cells.
• Statement C is incorrect: Bacteria are generally considered to be simple in structure but can exhibit complex behavior. Their cellular structure is less complex compared to eukaryotic cells, as they lack membrane-bound organelles and a well-defined nucleus. However, their behavior, including metabolic diversity, ecological roles, and genetic exchange, can be quite complex.
• Statement D is correct: Bacteria can be photosynthetic autotrophic (those that perform photosynthesis to produce their own food) or chemosynthetic autotrophic (those that obtain energy by oxidizing inorganic substances).

Therefore, the incorrect statement is C only.

The correct answer is: Lophotrichous

Explanation: Bacteria can have various arrangements of flagella that help in their mobility. These arrangements are categorized based on the number and location of flagella:

• Lophotrichous: Bacteria have a tuft of flagella emerging from one pole of the cell.
• Peritrichous: Flagella are distributed all over the surface of the bacterial cell.
• Monotrichous: A single flagellum arises from one pole of the bacterial cell.
• Amphitrichous: A single flagellum or a tuft of flagella emerges from both poles of the bacterial cell.

Key Points:.

• Flagellar arrangement aids bacteria in movement and is crucial for their survival and adaptation to different environments.
• The presence and pattern of flagella can be used to differentiate between various types of bacteria.

The correct answer is Platyhelminthes.Key Points

• Platyhelminthes are also known as flatworms.
• Flatworms have unsegmented, bilaterally symmetrical, soft bodies, with a triploblastic construction (comprising three layers of cells) and a lacking coelom, skeleton, and anus.
• Example includes Planaria, Liver fluke (Fasciola hepatica), and Tapeworm.

Additional Information

• Cnidaria includes jellyfish, corals, and sea anemones.
  • They have radial symmetry, a single body opening, and stinging cells called cnidocytes.
• Ctenophora includes comb jellies.
  • They have radial symmetry and cilia for movement but also have a complete digestive system.
• Porifera includes sponges.
  • They have asymmetrical or radial symmetry, no true tissues, and filter food through pores in their bodies.

The correct answer is Statement 1 is correct, and Statement 2 is incorrect.

Explanation:

• The kingdom Monera consists of prokaryotic organisms, which include bacteria and cyanobacteria (blue-green algae).
• Prokaryotic organisms do not have a well-defined nucleus; instead, their genetic material is found in the nucleoid region within the cell.
  • Statement 1 is correct: Monera consists of prokaryotic organisms like bacteria and cyanobacteria. These organisms lack true nuclei and membrane-bound organelles, and they are among the simplest forms of life.
  • Statement 2 is incorrect: Members of the kingdom Monera do not have a well-defined nucleus. Their genetic material is not enclosed within a nuclear membrane, which is a characteristic feature of eukaryotic cells, not prokaryotic cells.

Therefore, Statement 1 is correct, and Statement 2 is incorrect.

Key Points

• In bacteria, there are three different types of processes for the transfer of genetic information.
• These are namely Conjugation, Transduction and Transformation.
• Conjugation is the method of transfer of genetic material from one bacteria to another through a conjugation tube or by cell to cell in contact.
• This method was proposed by Lederberg and Tatum in E. coli.
• They discovered that the F-factor can move between E. coli cells and the concept of conjugation was put forth.
• The steps of Conjugation include:
  • Formation of the Pilus and the mating pair
  • Conjugal DNA synthesis
  • DNA transfer
  • Maturation

Explanation:

• Conjugation between F+ (donor) and F- (recipient) strains always yields an F+ strain.
• The F+ cells (donor) form a sex pilus and the donor cell pulls itself close to the recipient using pilus.
• The sex pilus forms a conjugation tube and facilitates direct contact between the donor and the recipient cells.
• DNA is transferred between cells during the starting of conjugation.
• The F+ cells contain both chromosomal DNA and F-plasmid.
• F- factor is known as fertility factor which is a chunk of DNA found in donor cells.
• The F-factor opens at the origin of replication.
• One strand is cut at the origin of replication, and the 5’ end enters the recipient cell.
• The F factor transfers from the F+ cells to the F- cells and the recipient cell turns into an F+ strain.
• The recipient cell now contains a copy of the F plasmid and becomes a donor cell.

Hence, the correct option is (1) F+ strain.

Concept:

• According to R.H. Whittaker's Five Kingdom system, all types of bacteria are placed in Kingdom Monera.
• Kingdom Monera thus includes unicellular prokaryotic organisms. Eg: Cyanobacteria
• Kingdom Monera is classified into two groups based on evolution: Archaebacteria and Eubacteria.

Important Points

• Option 1: Eubacteria - Peptidoglycan
  • ​This correlation is correctly matched.
  • The cell wall of eubacteria is made up of peptidoglycan.
  • Peptidoglycan also known as murein is found in only bacterial cells.
  • It provides rigidity to the cell wall.
• Option 2: Sulphur bacteria - Thermoacidophile 
  • This correlation is correctly matched.
  • The bacteria that can thrive in extremely hot and acidic areas are grouped under thermoacidophiles.
  • pH levels in these areas are generally less than 4. Temperatures are greater than 55°C.
  • Hot springs are one such area where thermoacidophiles can survive.
  • Thermoplasma is an example of a thermoacidophile.
  • Thermoplasma is found in acidic sulfur springs. In anaerobic respiration, the prokaryote is dependent on sulfur respiration.
• Option 3: Thermophile - Hot springs
  • ​This correlation is correctly matched.
  • Thermophiles are heat-loving organisms.
  • These organisms show optimal growth at higher temperatures - above 60°C.
  • Thermophiles are found in habitats with extreme conditions such as hot springs, hydrothermal vents, volcanic sites, etc.
  • Most thermophiles are archaebacteria.
  • Methanopyrus kandleri is a thermophile.
• Option 4: Dead sea - Methanogens ​
  • This correlation is mismatched.
  • Methanogens are a group of bacteria that are found in the gut of ruminants like cows.
  • They produce methane as a metabolic by-product.
  • Methanosaeta concilii is an example of methanogen.
  • Organisms that are found in the Dead sea withstand high salinities.
  • These organisms are referred to as halophiles.
  • Haloferax volcanii is an example of a halophile.

So the correct answer is option 4.