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
B.
Downy mildew of grapes
Bordeaux mixture was discovered by Millardet in France in 1882. It is prepared by dissolving 40 g of copper sulphate and 40 g of calcium hydroxide in 5 L of water. It was first used to control downy mildew disease of grape-vine that is caused by a fungus Plasmopara viticola. Black rust of wheat is caused by Puccinia graminis Tritici. The use of fungicide Dithane Z- 78 and Dithane M- 45 control the disease even at a lower concentration.
Loose smut of wheat is caused by Ustilago tritici. The use of fungicides (systemic fungicide like D- 735 and F- 461)give the quite encouraging result.
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 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