Ratio of speed of boat in downstream and speed of stream

Possession by two or more species of a similar or identical character state that has not been derived by both species from their common ancestor is called

What is the suitable temperature for nitrifying bacteria?

When fishes are reared along with plants, plants filtering water for the fishes and fishes provide organic matter to the plants, it is called as ____

Photoinhibition is associated with 

______ supresses branching and promote rhizosphere interactions.

Among the options given below, which of the following fishes possess electric organ?

A farmer harvested a crop with a total biomass of 800 kg, and the grain yield from the crop was 400 kg. Calculate the harvest index of the crop.

A reaper is used for

The only known nickel containing enzyme

Certain bacteria living in the soil converts nitrates into nitrites and then to free nitrogen Such bacteria are termed as