Question
Question: Find out the pairs, which are correctly matched. Cyanobacteria | (i) Biopesticides ---|--- M...
Find out the pairs, which are correctly matched.
| Cyanobacteria | (i) Biopesticides |
|---|---|
| Mycorrhiza | (ii) Solubilization of phosphate |
| C. Bacillus thuringiensis | (iii) Cry protein |
| D. Single cell protein | (iv) Rhizobia |
A. A and ii
B. C and iii
C. C and iv
D. A and iii
E. B an i
Solution
Biopesticides are pesticides derived from natural organisms, namely plants, animals, and bacteria. Phosphate Solubilization by microorganisms help plants to assimilate phosphate in edible form. Cry protein is encoded by the cry gene, which is toxic to animals. Rhizobia help in fixing atmospheric nitrogen in root nodules of specific legume.
Complete answer
Option A. A and ii: Cyanobacteria are blue-green algae. They are oxygen producers utilizing photosynthetic mechanisms. They are not involved in Solubilization of phosphate.
Option A is not correct.
Option B. C and iii: Bacillus thuringiensis is a gram-positive bacterium. It produces crystal inclusions, which act as endotoxins, called cry proteins. They are insecticidal proteins, which are effective against crop pests and mosquitoes.
Hence, Option B is correct
Option C. C and iv: Rhizobium helps in fixing atmospheric molecular nitrogen in leguminous plants. It is unrelated to Bacillus thuringiensis.
So, Option C is not correct
Option D. A and iii: Cyanobacteria are blue-green algae. They are oxygen producers utilizing photosynthetic mechanisms. They do not produce Cry protein.
Option D is not correct
Option E. B and i: Mycorrhiza is a mutual association between fungus and plant. It provides plants with nutrients. It is not used as a bio pesticide.
So, option E is not correct
Hence, Option B is the correct answer.
Note:
Cry protein is produced by the bacteria, Bacillus thuringiensis. It is secreted in an inactive form. It becomes active when ingested by the insect due to the alkaline pH present inside guts. On ingestion, there is lysis of epithelial cells of the gut, which will eventually lead to the death of insects. It is quite useful in agricultural pest control. It is mainly used in Bt cotton and Bt corn.