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 of
analogous organs
homologous organs
vestigial organs
vestigial organs
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?
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
B.
Archaea have some novel features that are absent in other prokaryotes and eukaryotes
The term archebacteria refer to the ancient origin of this group of bacteria, which seems to have diverged very early from the eubacteria. All archaebacteria share certain key characteristics.
i) Their cell wall lack peptidoglycan ( an important component of the cell wall of eubacteria).
ii) Lipids in the cell membrane of archaebacteria have a different structure than those in all other organisms.
iii) Archaebacteria have distinct ribosomal RNA sequence.
iv) some genes of archaebacteria possess introns unlike those of other bacteria.
Thermococcus, Methanococcus and Methanobacterium emplify
archaebacteria that contain protein homologous to eukaryotic core histones
archaebacteria that lack any histones resembling those found in eukaryotes but DNA is negatively supercoiled
bacteria whose DNA is relaxed or positively supercoiled but which have cytoskeleton as well as mitochondria
bacteria whose DNA is relaxed or positively supercoiled but which have cytoskeleton as well as mitochondria
A genetically engineered micro-organism use successfully in bioremediation of oil spills is a species of
Pseudomonas
Trichoderma
Xanthomonas
Xanthomonas
Which pair of the following belongs to Basidiomycetes?
Birds nest fungi and Pufballs
Pufballs and Calviceps
Peziza and Stink horns
Peziza and Stink horns