Ascientist has a very small sample of dna. to analyze the dna, which would be the most useful first step for the scientist to follow?

a. use restriction enzymes to make multiple copies of the dna.
b. use the polymerase chain reaction (pcr) to make multiple copies of the dna.
c. transfer the dna into bacteria, and allow the bacteria to be replicated many times.
d. use restriction enzymes to cut the dna into many small pieces.

B. Use the polymerase chain reaction (PCR) to make multiple copies of the DNA.

Explanation:

The scientist is to analyze a small sample of DNA, the most useful step to start this would be first the use of polymerase chain reaction to make various copies of that DNA sample. PCR is essential and quick process that gives a lot of copies within few hours. It uses the sample or target DNA, according to which the primers are designed. Taq polymerase and DNA polymerase are also used in the process, it consist of various cycles in which copies are made. There are three basic steps 'Denaturation', 'annealing', and 'extension'.

doctors i believe if i'm wrong sorry

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.