15 Minute Test: Kingdom Monera (NCERT) - NEET MCQ

Bacteria are grouped under four categories based on their shapes: the spherical coccus (pl.: coccl), the rod-shaped bacillus (pi.: bacilli), the comma-shaped vibrium (pl.: vibrio) and the spiral spirillum (pl.: spirilla).

Topic in NCERT: KINGDOM MONERA

Line in NCERT: "Bacteria are grouped under four categories based on their shape: the spherical Coccus (pl.: cocci), the rod-shaped Bacillus (pl.: bacilli), the comma-shaped Vibrium (pl.: vibrio) and the spiral Spirillum (pl.: spirilla)"

The Mycoplasma are organisms that completely lack a cell wall. They are the smallest living cells known and can survive without oxygen. Many mycoplasma are pathogenic in animals and plants.

Topic in NCERT: KINGDOM MONERA

Line in NCERT: "The Mycoplasma are organisms that completely lack a cell wall. They are the smallest living cells known and can survive without oxygen. Many mycoplasma are pathogenic in animals and plants."

(i) They are included in the group Archaebacteria.

Correct. The content mentions, "Archaebacteria differ from other bacteria in having a different cell wall structure."
(ii) They are responsible for the production of biogas in gobar gas plants.

Correct. The content states, "Methanogens are present in the gut of several ruminant animals...and they are responsible for the production of methane (biogas) from the dung of these animals."
(iii) They live in hot sulphur springs.

Incorrect. The content says, "These bacteria live in some of the most harsh habitats such as...hot springs (thermoacidophiles) and marshy areas (methanogens)." Methanogens are not specified to live in hot sulphur springs; thermoacidophiles do.
(iv) They are present in the gut of several ruminant animals such as cows and buffaloes

Topic in NCERT: Archaebacteria

Line in NCERT: "Methanogens are present in the gut of several ruminant animals such as cows and buffaloes and they are responsible for the production of methane (biogas) from the dung of these animals."

The cyanobacteria are unicellular, colonial or filamentous, freshwater/marine or terrestrial algae. The colonies are generally surrounded by gelatinous sheath. They often form blooms in polluted water bodies. Some of these organisms can fix atmospheric nitrogen in specialised cells called heterocysts, e.g., Nostoc and Anabaena

It is filamentous blue green algae- Nostoc

Both Archaebacteria and eubacteria are classified under kingdom monera.

Topic in NCERT: KINGDOM MONERA

Line in NCERT: "In the five kingdom classification, bacteria are included in Kingdom Monera."

Cyanobacteria have chlorophyll-a, similar to green plants, which allows them to perform photosynthesis. They are photosynthetic autotrophs and can be unicellular, colonial, or filamentous algae.

Topic in NCERT: Eubacteria

Line in NCERT: "The cyanobacteria (also referred to as blue-green algae) have chlorophyll a similar to green plants and are photosynthetic autotrophs."

Cyanobacteria can fix atmospheric nitrogen in specialised cells called heterocysts, e.g., Nostoc and Anabaena. Chemosynthetic autotrophic bacteria oxidise various inorganic substances such as nitrates, nitrites and ammonia and use the released energy for their ATP production. They play a great role in recycling nutrients like nitrogen, phosphorous, iron and sulphur.

Topic in NCERT: Eubacteria

Line in NCERT: "Some of these organisms can fix atmospheric nitrogen in specialised cells called heterocysts, e.g., Nostoc and Anabaena."

To identify the correct statements about bacteria reproduction:

- A: Bacteria reproduce mainly by fission: Correct. Binary fission is the primary method of bacterial reproduction.
- B: Bacteria reproduce by production of gametes: Incorrect. Bacteria typically reproduce asexually, not through the production of gametes.
- C: Under unfavorable conditions, Bacteria produce spores: Correct. Bacteria form spores as a survival strategy in harsh environments.
- D: Bacteria reproduce by a sort of sexual reproduction:  Correct. Bacteria usually  reproduce asexually and reproduce by a sort of sexual reproduction by adopting a primitive type of DNA transfer from one bacterium to the other.

Topic in NCERT: KINGDOM MONERA

Line in NCERT: "Bacteria reproduce mainly by fission. Sometimes, under unfavourable conditions, they produce spores. They also reproduce by a sort of sexual reproduction by adopting a primitive type of DNA transfer from one bacterium to the other."

The cyanobacteria are unicellular, colonial or filamentous, freshwater/marine or terrestrial algae. The colonies are generally surrounded by gelatinous sheath. They often form blooms in polluted water bodies. Some of these organisms can fix atmospheric nitrogen in specialised cells called heterocysts, e.g., Nostoc and Anabaena. Chemosynthetic autotrophic bacteria oxidise various inorganic substances such as nitrates, nitrites and ammonia and use the released energy for their ATP production. They play a great role in recycling nutrients like nitrogen, phosphorous, iron and sulphur.

Topic in NCERT: Eubacteria

Line in NCERT: "Some of these organisms can fix atmospheric nitrogen in specialised cells called heterocysts, e.g., Nostoc and Anabaena."

Monera kingdom includes prokaryotes - mycoplasma bacteria, actinomycetes and cyanobacteria or blue greet algae. Alongwith fungi, they are decomposers and mineralisers of the biosphere.

Topic in NCERT: KINGDOM MONERA

Line in NCERT: "In the five kingdom classification, bacteria are included in Kingdom Monera."

To identify the incorrect statement regarding bacteria:

- A: Bacteria are the most abundant microorganisms.
- B: Bacteria live in extreme habitats where very few other life forms can survive.
- C: Bacteria as a group show the most extensive metabolic diversity.
- D: They are obligate intracellular parasites.

The incorrect statement is: D: They are obligate intracellular parasites.

Explanation: Bacteria can be classified as intracellular or extracellular, with many living freely outside cells. While some bacteria can be obligate intracellular parasites, not all bacteria exhibit this behavior.

Topic in NCERT: KINGDOM MONERA

Line in NCERT: "Many of them live in or on other organisms as parasites."

Cyanobacteria (also known as blue-green algae) are photosynthetic autotrophs and possess chlorophyll a, similar to green plants. They can be unicellular, colonial, or filamentous and are capable of nitrogen fixation in specialized cells called heterocysts, which helps in converting atmospheric nitrogen into a usable form for the ecosystem. They are found in both freshwater and marine environments.

Assertion (A) is correct because cyanobacteria can perform photosynthesis using chlorophyll a and can fix nitrogen in specialized cells called heterocysts. These abilities help them thrive in various environments, including freshwater and marine ecosystems.

However, Reason (R) is incorrect because cyanobacteria can perform photosynthesis in both aquatic and terrestrial environments, as long as there is sufficient light. The assertion is correct, but the reasoning given is false, so the correct answer is Option C.