Studying the same group of individuals from age 2 to age 40 is an example of which of the following research methods?
a. cross-sectional
b. longitudinal
c. archival
d. none of the above

a. Cross sectional

Explanation:

Longitudinal research is a method in with data is recollected repeatedly over a period of time from the same subjects. Archival method is gathering information from archival records. Cross-sectional studies analyze data from a population at a specific period of time, this population can be integrated by people with different characteristics (in this case, age) but with another characteristics in common, for example, ethnicity, gender, etc)

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ans.

dna fingerprinting is defined as a process that determines the dna characteristics of an individual. these dna characteristics are unique among individuals as their fingerprints, so it is known as dna fingerprinting.

steps of dna fingerprinting includes extraction of dna from sample, amplification of dna, restriction digestion of amplified dna, and then analysis of dna by gel electrophoresis, respectively.

thus, the next step performed by the scientist is 'to cut the amplified dna (obtained by polymerase chain reaction) by restriction enzymes that cleave the dna into fragments and their analysis.'