Biology Test 3

In agriculture, green manure is created by leaving uprooted or sown crop parts to wither on a field so that they serve as a mulch and soil amendment. The plants used for green manure are often cover crops grown primarily for this purpose. Typically, they are ploughed under and incorporated into the soil while green or shortly after flowering. Green manure is commonly associated with organic farming and can play an important role in sustainable annual cropping systems.

Viruses are not decomposers, they cannot fix nitrogen, they are mostly pathogenic and hence are not used as biofertilizers. Whereas bacteria, fungi and cyanobacteria can serve as biofertilizers.

Acetic acid is used as coloring agents, in plastic industries etc. Citric acid is used in food industries, in cleaning of grease. Lactic acid is mostly used in curd and fermented food products production. Gluconate salts are used in malaria treatment

Cloning vector which is usually chosen to be a plasmid must never integrate into a chromosomal DNA after transformation. It is always autonomously replicating and having high copy numbers. Point (3) and (4) are also essentials for cloning purposes.

Streptomycin was discovered by Selman Waksman in 1943 from a specie of bacteria, Streptomyces griseus found in soil.

Littoral zone is the zone which is present on the edge of the water bodies. Sunlight enters this zone and growth of plants can be seen.

Predators act as conduits for energy transfers. They transfer energy from producers to higher trophic levels.

Decomposition is a process in which decomposers break down complex organic matter into inorganic ones. In leaching Soluble substances from fragmented detritus gets dissolved in water and percolate soil and precipitated as unavailable salts. 
Detritivores breakdown detritus into smaller particles by the process known as fragmentation.