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
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.
archaebacteria that contain protein homologous to eukaryotic core histones
Inspection of domain Archaea shows that two sub-divisions exist the Euryarchaeota and the Crenarchaeota. The Archaea are chemotrophic although Halobacterium can use light to make ATP. Many other are chemolithotrophs with ATP. Many other are chemolithotrophs with hydrogen gas being a widely used energy source.The Euryarchaeota includes Methanobacterium, Methanococcus, Thermococcus. The differential features among bacteria, Archaea and Eukarya are:
Characteristic |
Bacteria |
Archaea |
Eukarya |
Prokaryotic cell |
Yes |
Yes |
No |
Circular DNA |
Yes |
Yes |
No |
Histone protein |
No |
Yes |
Yes |
Membrane-bound Nucleus |
No |
NO |
Yes |
Ribosome |
70S |
70S |
80S and 70S |
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