Test: Kingdom Protista (NCERT) - NEET MCQ

Slime moulds are saprophytic protists. The body moves along decaying twigs and leaves engulfing organic material. Under suitable conditions, they form an aggregation called plasmodium which may grow and spread over several feet.

Line in NCERT: "Slime moulds are saprophytic protists."

Slime moulds, under favorable conditions, move along decaying twigs and leaves engulfing organic material. This behavior allows them to thrive by feeding on organic matter and growing as a result.

. During unfavourable conditions, the plasmodium differentiates and forms fruiting bodies bearing spores at their tips. The spores possess true walls. They are extremely resistant and survive for many years, even under adverse conditions. The spores are dispersed by air currents.

Line in NCERT: "Slime moulds are saprophytic protists. The body moves along decaying twigs and leaves engulfing organic material."

Cholera, typhoid, tetanus are well-known diseases caused by Bacteria 

Dinoflagellates, euglenoids and slime moulds are placed under kingdom protista 

Diatoms and Dinoflagellates are the chief 'producers' in the oceans

onmy 1 statement Members of kingdom Protista are primarily aquatic is correct 

Line in NCERT: "Members of Protista are primarily aquatic."

All single-celled eukaryotes are placed under Protista, but the boundaries of this kingdom are not well defined. What may be ‘a photosynthetic protistan’ to one biologist may be ‘a plant’ to another. Kingdom Protista include Chrysophytes, Dinoflagellates, Euglenoids, Slime moulds and Protozoans under Protista

Line in NCERT: "we include Chrysophytes, Dinoflagellates, Euglenoids, Slime moulds and Protozoans under Protista."

Option c is correct Paramoceium is ciliated protozoan

Entamoeba histolytica is amoeboid, Trypanosoma is Flagellated, Plasmodium is sporozoan.

Line in NCERT: "Ciliated protozoans: These are aquatic, actively moving organisms because of the presence of thousands of cilia. Example: Paramoecium (Figure 2.4d)."

diatoms have left behind large amount of cell wall deposits in their habitat; this accumulation over billions of years is referred to as ‘diatomaceous earth’. Being gritty this soil is used in polishing, filtration of oils and syrups. Diatoms are the chief ‘producers’ in the oceans.     

Line in NCERT: "Being gritty this soil is used in polishing, filtration of oils and syrups."

• Diatoms (A) have a cell wall that is embedded with silica, giving them a rigid structure. This makes the correct match A-b.

• Dinoflagellates (B) have cellulose plates in their cell walls, which are characteristic of this group, often leading to their description as having "armored" cells. This makes the correct match B-d.

• Euglenoids (C) do not have a traditional cell wall; instead, they have a flexible outer layer known as a pellicle, which is a protein-rich layer. This makes the correct match C-a.

• Slime moulds (D) are known for producing spores that have true walls, used in their reproductive cycle. This makes the correct match D-c.

- Correct Answer: D
- Explanation:
- Protista is a kingdom of eukaryotic organisms, which means they have a , cell body contains a well defined nucleus( presence of nuclear membrane) and other membrane-bound organelles
- Monera, on the other hand, are prokaryotic organisms lacking a true nucleus and nuclear membrane.

Otherwise both have cell wall, unicellular and mode of nutrition is same.

Line in NCERT: "Being eukaryotes, the protistan cell body contains a well defined nucleus and other membrane-bound organelles."

In diatoms the cell walls form two thin overlapping shells, which fit together as in a soap box. The walls are embedded with silica and thus the walls are indestructible. Thus, diatoms have left behind large amount of cell wall deposits in their habitat; this accumulation over billions of years is referred to as ‘diatomaceous earth’. Being gritty this soil is used in polishing, filtration of oils and syrups. Diatoms are the chief ‘producers’ in the oceans

Line in NCERT: "In diatoms the cell walls form two thin overlapping shells, which fit together as in a soap box."

Flagellated protozoans: The members of this group are either free-living or parasitic. They have flagella. The parasitic forms cause diaseases such as sleeping sickness. Example: Trypanosoma

Line in NCERT: "Flagellated protozoans: The members of this group are either free-living or parasitic. They have flagella. The parasitic forms cause diseases such as sleeping sickness. Example: Trypanosoma."

All protozoans are heterotrophs and live as predators or parasites.

Line in NCERT: "All protozoans are heterotrophs and live as predators or parasites."

All single-celled eukaryotes are placed under Protista, but the boundaries of this kingdom are not well defined

Line in NCERT: "Kingdom Protista includes all single-celled eukaryotes such as Chrysophytes, Dinoflagellates, Euglenoids, Slime-moulds and Protozoans."

Dinoflagellates appear yellow, green, brown, blue or red depending on the main pigments present in their cells. The cell wall has stiff cellulose plates on the outer surface. Most of them have two flagella; one lies longitudinally and the other transversely in a furrow between the wall plates

Line in NCERT: "These organisms are mostly marine and photosynthetic. They appear yellow, green, brown, blue or red depending on the main pigments present in their cells. The cell wall has stiff cellulose plates on the outer surface. Most of them have two flagella; one lies longitudinally and the other transversely in a furrow between the wall plates."

First option is correct 

Instead of a cell wall, euglenoids they have a protein rich layer called pellicle which makes their body flexible.

option 2 is incorrect because Though they are photosynthetic in the presence of sunlight, when deprived of sunlight they behave like heterotrophs by predating on other smaller organisms.

 Option 3 is incorrect because Interestingly, the pigments of euglenoids are identical to those present in higher plants. 

option 4 is incorrect beacuse Majority of them are fresh water organisms found in stagnant water.

Line in NCERT: "Instead of a cell wall, they have a protein rich layer called pellicle which makes their body flexible."

- The Assertion (A) is correct because it accurately describes the nutritional habits of protozoans as heterotrophs that mostly function as predators or parasites.

- The Reason (R) is false since protozoans do not possess chloroplasts and cannot perform photosynthesis; they are dependent on other organisms for nutrition.

- Therefore, the Reason is not the correct explanation of the Assertion. Since the Assertion is true and the Reason is false, the correct option is Option C.