Two groups of tomatoes were grown under laboratory conditions, one with humus added to the soil and one a control without humus. The leaves of the plants grown without humus were yellowish (less green) compared with those of the plants grown in humus-enriched soil. The best explanation for this difference is that
A) the healthy plants used the food in the decomposing leaves of the humus for energy to make chlorophyll.
B) the humus made the soil more loosely packed, so water penetrated more easily to the roots.
C) the humus contained minerals such as magnesium and iron, needed for the synthesis of chlorophyll.
D) the heat released by the decomposing leaves of the humus caused more rapid growth and chlorophyll synthesis.
E) the healthy plants absorbed chlorophyll from the humus.
A plot of trophic diversity across the major groups of organisms shows highest trophic diversity amo
Blue whale skeleton, outside the Long Marine Laboratory at the University of California, Santa Cruz
Laboratory tests to screen for infection
Laboratory mice demonstrate that genetic differences can have profound effects on the propensity to
Table 6.1 illustrates the main regime types and their differences. It breaks the regimes into four
Typical laboratory emergency shower.