(a) Chlorella
(b) Scenedesmus
(c) Chroococcus
(d) Chlamydomonas

(1) Agasthiyamalaia pauciflora
(2) Harawickia binata

(a) Banagudi Shola
(b) Thirukurungudi
(c) Udaiyankudikadu
(d) Sittannavasal

In-situ conservation	Ex-situ conservation
Conservation of species In their natural habitat. E.g: Biosphere reserves	Conservation of species outside their natural habitat. E.g: Zoological parks

A non-native species to the ecosystem or country under consideration that spreads naturally, interferes with the biology and existence of native species, poses a serious threat to the ecosystem and causes economic loss.
e.g., Eichhornia crassipes

Social forestry refers to the management of forests and afforestation on barren lands with the purpose of helping the environmental, social and rural development and benefits.

The production of woody plants combined with pasture is referred to silvopasture systems
The trees and shrubs may be used primarily to produce fodder for livestock or they may be grown for timber, fuelwood, and fruit or to improve the soil.

(i) Petunia species act as indicators for Nitrate pollution.
(ii) Gladiolus species acts as indicators for Fluoride pollution.

The International treaty called the Montreal Protocol (1987) was held in Canada on substances that deplete ozone layer and the main goal of it is gradually eliminating the production and consumption of ozone depleting substances and to limit their damage on the Earth's ozone layer.

Ozone layer is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. The ozone layer is also called as the ozone shield and it acts as a protective shield, cutting the ultra-violet radiation emitted by the sun.

Dobson Unit is the unit of measurement for total ozone. One DU is the number of molecules of ozone that would be required to create a layer of pure ozone 0.01 millimeter thick at a temperature of 0° C and a pressure of 1 atmosphere.

Paddy field, fossil fuel production, bacteria in water bodies, cattle rearing, non-wetland soils, and forest & wildfires.

CSS - Carbon Capture and Storage.

Casuarina, Eucalyptus, Teak, Malai vembu.

The decline in the thickness of the ozone layer over the restricted area is called the Ozone hole.