Ecool can be considered a manufacturer unit in the field of genetic engineering

This statement is best described by the option B. The recombinant DNA produced by the combination of a vector and gene of interest in the E.coli which produces multiple copies of this recombinant DNA along with the chromosomal DNA and expresses the gene.

Explanation:

In genetic engineering, the gene of interest is combined with a vector e.g. plasmid and inserted into the most suitable carrier for these recombinants. This carrier acts as the manufacturing unit for the gene of interest as it produces multiple copies when it replicates in a short period of time. E.coli is considered to be one of the best manufacturing units in the field of genetic engineering as it has a very flexible replication time.

c. heat from the poles back down towards the equator.

the sun creates it's own light, also gives light and life to bunch of stuff like plants,animals,humans etc.photosyntesis is the process of making food which needs sun,water,nutrients etc.