Phylogenetic system of classification is based onÂ
evolutionary relationships
morphological features
chemical constituents
chemical constituents
T O Diener discovered a
free infectious RNA
free infectious DNA,
infectious protein
infectious protein
Peripatus is a connecting link between
Ctenophora and Platyhelminthes
Mollusca and Echinodermata
Annelida and Arthropoda
Annelida and Arthropoda
Trichoderma harzianum has proved a useful microorganism forÂ
bioremediation of contaminated soils
reclamation of wastelands
gene transfer in higher plants
gene transfer in higher plants
Which one of the following is linked to the discovery of Bordeaux mixture as a popular fungicide?
Bacterial leaf blight of rice
Downy mildew of grapes
Loose smut of wheat
Loose smut of wheat
Thorn of Bougainvillea and tendril of Cucurbita are examples ofÂ
analogous organs
homologous organs
vestigial organs
vestigial organs
B.
homologous organs
Thorns of Bougainvillea and tendrils of Cucurbita are homologous organs. These are modified branches and are axillary in position. It means axillary branches in Bougainvillea are modified into thorns for protection from burrowing animals and in Cucurbita into tendrils for climbing.
The analogous organs have the almost similar appearance and perform the same function but t these develop in totally different groups and are totally different in their basic structure and development origin. The phyllode of Ruscus or cladode of Asparagus is analogous to leaves of other plants.
The vesigial or rudimentary organs are useless remnants of structures of organs. which might have been large and functional in ancestors, eg, cutin covered stomata on the stem of cactiplants.
In the light of recent classification of living organisms into three domains of life (bacteria, archaea and eukarya), which one of the following statement is true about archaea?Â
Archaea resemble eukarya in all respects
Archaea have some novel features that are absent in other prokaryotes and eukaryotes
Archaea completely differ from both prokaryotes and eukaryotes
Archaea completely differ from both prokaryotes and eukaryotes