Due to decreased light penetration, which area of rivers and streams will have less diversity of plant life?
a. the source
b. the mouth
c. the middle portion
d. none of the above

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures

The wings of insects, birds, and bats evolved independently but carry out similar functions. this is an example of a. analogous structures. b. embryonic structures. c. vestigial structures. d. homologous structures.

If 360 joules of work are needed to move and create a distance of 4 m what is the weight of the crate