Question

Question 26:
When an alien species (plant or animal) that does not belong to an ecosystem is introduced, it spreads and
competes with the native plants for space and nutrients and becomes problematic in the absence of
natural enemies. These intruders are called invasive alien species.
What are the ill effects of an invasive species like water hyacinth?
i. Blockage of sunlight from reaching native aquatic plants.
ii. Starving the water of carbon dioxide
iii. Domination and phasing out of fish and other native species.
iv. Change in the water quality with respect to the dissolved oxygen and the water pH due to release
of CO2 .
v. Starving the water of oxygen.
vi. Desilting of the water body
vii. An increase in algae blooms, mosquito infestation due to dense matting and decreased water flow.
a) i , ii, iii, iv, v
b) i, iii, v, vii, iv
c) iii, v, vi, vii
d) iii, iv, v, vi

Answer 1

Answer:

However, when these alien species begin to have negative consequences in the new habitat, they are called invasive species. Invasive species may cause environmental harm, economic harm, or impact human health. A key factor that makes many species invasive is a lack of predators in the new environment

Answer 2

The answer is b

I hope this helps

Explanation:

i. Blockage of sunlight from reaching native aquatic plants.

TRUE AS THE ALGAL BLOOMS DON'T ALLOW THE SUNLIGHT TO PASS THROUGH

ii. Starving the water of carbon dioxide

FALSE Starving the water of OXYGEN

iii. Domination and phasing out of fish and other native species.

TRUE

iv. Change in the water quality with respect to the dissolved oxygen (LESS)and the water pH (DECREASES MEANS BECOMES ACIDIC) due to release

of CO2 .TRUE

v. Starving the water of oxygen.

TRUE

vi. Desilting of the water body

FALSE. It IS OF NO USE

vii. An increase in algae blooms, mosquito infestation due to dense matting and decreased water flow.

TRUE

I HOPE THIS HELPS ( ╹▽╹ )