The concentration of nitrates is often higher in plant roots than it is in the soil around them. Plants maintain this difference in concentration through
a. active transport
b. diffusion
c. excretion
d. coordination
Ans: a. active transport
You might also like to view...
When two homologous chromosomes align and exchange a segment of their genetic material, which can make linked traits seem independent of one another, this process is called _________.
a. epistasis b. recombination c. reciprocal cross d. codominance
The DNA strand that is replicated smoothly and continuously is called the:a
primary strand. b. first strand. c. leading strand. d. alpha strand. e. lagging strand
A fern is an example of what type of plant?
a) seedless vascular b) flowering plant c) nonvascular d) naked seed plant
According to geological evidence, oxygen levels in the atmosphere began to increase about 2 billion years ago. This favored the evolution of multicellular, terrestrial organisms because:
A. More oxygen was available for cell respiration B. More oxygen was available for photosynthesis C. Some of the oxygen was used to help establish the ozone layer, and protect against harmful UV radiation D. All multicellular organisms require oxygen to survive E. More than one above is correct