What will be the environmental consequence of $25\%$  increase of $CO_2$ level in our atmosphere

Population density of terrestrial organisms is measured in terms of individuals per

Presence of plants arranged into well defined vertical layers depending on their height can be seen best in

The abundance of a species population within its habitat is called

In a sea shore, the benthic animals live in sandy, muddy and rocky substrata and accordingly developed the following adaptations.

$(a)$ Burrowing

$(b)$ Building cubes

$(c)$ Holdfasts / peduncle

Find the suitable substratum against each adaptation.