4680 years
1 x .5 = .5
.5 x .5 = .25
.25 x .5 = .125
You multiplied 3 times, so 3 times 1,620 is 4,680.
Answer:
D
Explanation:
Dude just sounds like an asswipe. it's definitely not B, or C. Last two remaining makes it A or D, and the first part of the para doesn't match up (about him laughing) with being avoidant if he goes out of his way. He's just self-centered and lazy, leaving D left.
Answer: multiple copies of a targeted region of DNA.
Explanation: Polymerase chain reaction is a technique used in molecular biology to produce millions of copies of specific DNA segment. This involves taking a minute sample of DNA segment and hugely amplifying it to produce multiple copies of the segment. PCR procedure has three step:
1). Heating the double stranded DNA containing the targeted DNA region to be amplified in order to separate the strands.
2). Allowing the strands to cool and adding synthetic oligonucleotide primers.
3). Addition of thermostats DNA polymerase to catalyze 5'->3' DNA synthesis.
The process is repeated in about 25 to 30 cycles and the amplified DNA can be cloned.
PCR was invented in 1983 by Kary Mullis.