to allow single-celled<span> organisms to produce useful products</span>
I would have to say (D.) if it's been 150 years.
The best answer is (1)
Fossil fuels are commercially available as an energy source.
They are very easy to find. More and more extractions of fossil fuels is going on everyday. With advancement in science and technology, the refineries and extraction procedures have improved a lot. This makes their availability even better.
Fossil fuels are also easily combustible. Most combustion engines need to be powered with little amount of fuel to produce large amount of energy. Very large amounts of electricity can be generated from fossil fuels.
Plants store their sugar in the form of starch
The layer of connective tissue, called the _perimysium_ , extends inward from the epimysium and separates the muscle tissue into small sections. these sections contain bundles of skeletal muscle fibers called _fascicles_ .
Additionally, bundles of contractile proteins called fibrils fill a muscle cell, called a fiber. Outside of each fiber, is the connective tissue endomysium. Bundles of fibers form fascicles, surrounded by perimysium. Bundles of fascicles and perimysium comprise the entire muscle organ, which is enclosed by epimysium.
