Which of the following is the source of carbon to plants
Atmospheric $CO_2$
$CO_2$ of carbonate rocks
Fossils
All the above
Percentage of Photosynthetically Active Radiation (PAR) that is captured by plants in synthesis of organic matter is
Mention type of nutrient cycling explaining it.
In the vast marine ecosystem, certain sea develop red colouration. This red colour is due to the presence of large population of which one of the following organisms?
The forest that colours in autumn is
An ecosystem may be defined as