Viroids are the smallest known infectious agents, consisting solely of a short strand of circular, single-stranded RNA without a protective protein coat. Unlike viruses, viroids do not code for proteins but can replicate within host plants and cause disease.
The size of viroid RNA typically ranges from about 300 to 400 nucleotides. This small genome size allows viroids to interfere with host cellular processes, leading to various plant diseases.
Given below are two statements:
Statement (i): Stubby root nematode are also known as Longidorids
Statement (ii): Stubby root nematode are also known as Trichodorids
In light of the above statements, choose the most appropriate answer from the options given below.
Given below are two statements:
Statement (I): Bean yellow mosaic virus is transmitted by Aphis glycines.
Statement (II): Chilli mosaic virus is transmitted by Aphis craccivora.
Given below are two statements:
Statement (I): Virus transmission by whitefly is persistent and circulative type.
Statement (II): Virus transmission by hoppers is circulative and usually propagative type.
Given below are two statements:
Statement (i): Xiphinema spp of nematodes is also known as Dagger nematodes
Statement (ii): Xiphinema spp of nematodes is also known as Lesion nematodes
In light of the above statements, choose the most appropriate answer from the options given below.
Match the pollination types in List-I with their correct mechanisms in List-II:
List-I (Pollination Type) | List-II (Mechanism) |
---|---|
A) Xenogamy | I) Genetically different type of pollen grains |
B) Ophiophily | II) Pollination by snakes |
C) Chasmogamous | III) Exposed anthers and stigmas |
D) Cleistogamous | IV) Flowers do not open |