What is the main difference between active and passive transport

The energy needs of a human population are not affected by

Which gas found in the earth's atmosphere greatly impacts the daily range of temperature on earth. a) oxygen b) hydrogen c) nitrogen d) water vapor

Which scientific design has both practical limitations and limitations due to scale? studying the effect of bleach on the growth of mold spores exposing cultures of duckweed to different intensities of light observing the replication of dna molecules with a hand lens using colored marbles to model a cross between two colors of rabbits