Two groups of tomatoes were grown under laboratory conditions, one with humus added to the soil (Group 1) and the other a control without humus (Group 2). The leaves of the plants grown without humus were yellowish (less green) compared with those of the plants grown in the humus-enriched soil. The best explanation for this difference is that the: Group of answer choices

the humus contains the minerals necessary for chlorophyll synthesis

Explanation:

The yellowness of leaves in plants can be attributed to inadequate chlorophyll in the plant. The chlorophyll is responsible for the greenness appearance of the leaves of plants and when it is present in inadequate quantity, the leaves appear yellowish in color.

Some of the minerals necessary for the formation of chlorophyll include magnesium, nitrogen, and iron. It thus means that the humus supplied to the soil of group 1 plant has the necessary minerals to synthesize chlorophyll while the soil of group 2 plants is deficient in some or all the minerals required for chlorophyll synthesis.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."