Please help
a food chain is represented below.
phytoplankton ⟶ krill ⟶ mackerel ⟶ sea gull
Which organism in the food chain is a secondary consumer?

Secondary consumer is Mackerel .

Explanation:

In this food chain ,

Phytoplankton is Primary Producer ,

Krill is Primary Consumer ,

Mackerel is Secondary Consumer and

Sea gull is Tertiary Consumer .

Primary producer is an organism that produces its own food.

Primary consumer is an organism that feeds on producer.

Secondary consumer is an organism that feeds on primary consumer.

Tertiary consumer is an organism that feeds on secondary consumer.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

no i don't feel that humans have oversubscribed some medications