Question

The residents of Nanganallur and Adambakkam wanted to revive an environment park on
AdambakkamEri. The lake needs to be desilted and deepened and a bund is to be formed for a walkers’
path. Moreover, steps are to be taken to prevent the discharge of sewage through storm water drains and
the dumping of garbage on the lake bunds. The environmentalists say that invasive species like water
hyacinth have clogged this water body. Also, the discharge of sewage into the lake has resulted in the
growth of unwanted plants. This is blocking the air-water interface, thereby reducing the dissolved oxygen
in the water and killing a lot of fish. The water bodies clogged by the invasive species also become a
breeding ground for mosquitoes. The State Government has been requested to expedite the works for this
at the earliest.


Raghav wants to undertake a survey to support the hypothesis “Non-native invasive plants make it difficult
for native plants to grow.” The steps that are required are listed below, but in a jumbled order.
i. As per your observation, make a note of the number of species that are suspected to be invasive in
this area.
ii. If possible, compare with spaces that do not have any invasive species.
iii. Identify or earmark an area for study.
iv. Note the time for the growth (in size as well as numbers) of invasive species which grow very
rapidly over the other species.
v. Read about invasive species from books, newspapers and online resources.
vi. Take careful tour of the area to locate invasive plants by using images from books and newspapers.
vii. Observe the death/ diminishing of some native species.
viii. Identify native and invasive plants of the locality/ surrounding area.
a) i, iv, vii, ii, v, iii, vi, viii
b) ii, iii, v, viii, i, iv, vi, vii
c) v , viii, iii, vi, i, iv, vii, ii
d) v, viii, i, vii, ii, iv, iii, vi

Answer 1

I,iv, vii, ii, v, iii, vi, viii