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300 questions in this collection · Page 23 of 30
Question 221 of 300
📘 CLASS XI
Biological Classification
Assertion (A): The spores of slime moulds are extremely resistant and can survive for many years under adverse conditions.
Reason (R): The spores of slime moulds possess true walls.
True-walled spores are highly resistant and survive adverse conditions for many years.
Question 222 of 300
📘 CLASS XI
Biological Classification
Assertion (A): Trypanosoma is a pathogen that causes sleeping sickness.
Reason (R): Trypanosoma is an example of an amoeboid protozoan.
Trypanosoma causes sleeping sickness but belongs to the flagellated protozoans.
Question 223 of 300
📘 CLASS XI
Biological Classification
Assertion (A): Paramoecium can actively steer water laden with food into its gullet.
Reason (R): Paramoecium possesses thousands of cilia that undergo coordinated movement.
Coordinated beating of cilia directs food-laden water into the gullet.
Question 224 of 300
📘 CLASS XI
Biological Classification
Assertion (A): Marine forms of amoeboid protozoans have silica shells on their surface.
Reason (R): All amoeboid protozoans are obligate parasites.
Marine amoeboid protozoans possess silica shells, whereas only some amoeboid protozoans are parasitic (e.g. Entamoeba).
Question 225 of 300
📘 CLASS XI
Biological Classification
Assertion (A): Euglenoids lack a cell wall.
Reason (R): Euglenoids possess a protein-rich layer called a pellicle which makes their body flexible.
Both statements are true. Euglenoids lack a cell wall because it is replaced by a protein-rich pellicle, which provides flexibility to the cell. Hence, the Reason correctly explains the Assertion.
Question 226 of 300
📘 CLASS XI
Biological Classification
Assertion (A): Plasmodium is a notorious sporozoan that causes malaria.
Reason (R): Sporozoans have an infectious spore-like stage in their life cycle.
Plasmodium causes malaria and belongs to Sporozoa. Although sporozoans possess an infectious spore-like stage, this feature alone does not explain why Plasmodium causes malaria.
Question 227 of 300
📘 CLASS XI
Biological Classification
Assertion (A): We keep food in the refrigerator to prevent it from going bad.
Reason (R): Fungi prefer to grow in warm and humid places, so the cold environment inhibits their growth.
Refrigeration inhibits the growth of fungi and many bacteria that thrive in warm and humid conditions.
Question 228 of 300
📘 CLASS XI
Biological Classification
Assertion (A): Some fungal hyphae are called coenocytic hyphae.
Reason (R): These hyphae are continuous tubes filled with multinucleated cytoplasm and lack septae.
Coenocytic hyphae are defined as aseptate, multinucleate hyphae.
Question 229 of 300
📘 CLASS XI
Biological Classification
Assertion (A): Fungi are exclusively heterotrophic organisms.
Reason (R): They absorb soluble organic matter from dead substrates or depend on living plants and animals.
Fungi obtain nutrition saprophytically or parasitically, making them heterotrophic.
Question 230 of 300
📘 CLASS XI
Biological Classification
Assertion (A): In fungi, the fusion of protoplasms between two gametes is called karyogamy.
Reason (R): Meiosis occurs in the zygote to result in haploid spores.
Fusion of protoplasm is called plasmogamy, whereas karyogamy is the fusion of nuclei. Meiosis in the zygote produces haploid spores.