Help me plz So why only 3-4 trophic levels per food chain?
How does this affect relative population sizes between
levels?

well schools are being forced to embrace computers. unlike their "digital immigrant" teachers, these students are "digital natives", born into a world where technology is an integral part of everyday life. almost every student has access to a multitude of computers, laptops and tablet devices. it would be crazy to assume an assignment would  not be written on computer in this day and age.

don't delete this trying to

the cytokine-activated janus kinase (jak)-signal transducer and activator of transcription (stat) pathway has an important role in the control of immune responses. dysregulation of jak-stat signaling is associated with various immune disorders.

layer 3 is younger than layer 6.