In which of the following aquatic ecosystems is the maximum biomagnification observed?

Which of the following statements are correct regarding Eutrophication?
$I-$ Streams entering into a lake introduce nutrients like nitrogen and phosphorus,which encourage the growth of aquatic organisms.
$II-$ As the lake's fertility increases,plant and animal life flourish.
$III-$ Organic remains begin to deposit at the bottom of the lake.
$IV-$ Organic waste materials continue to accumulate in the lake.
$V -$ The lake becomes shallower and warmer.
$VI -$ Cold-water organisms are replaced by warm-water organisms.
$VII -$ Marsh plants take root in the shallows and begin to fill in the original lake basin.

Leaf curling is caused by

The main air pollutant is:

Which of the following is a biodegradable pollutant?

Which one of the following is not correct with regard to the harmful effects of particulate matter of the size $2.5 \ \mu m$ or less?