The polymerase chain reaction (PCR) is used to generate: multiple copies of a targeted region of DNA. a single copy of a targeted region of DNA. single copies of whole chromosomes. multiple copies of whole chromosomes. multiple copies of whole chromosomes and a targeted region of DNA.

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.

hello there the answer is d

d concave shape of wave rock

explanation:

the concave shape of wave rock is a very good evidence that supports the evolution of earth due to chemical weathering. if we talk about structure of   wave rock, studies have estimated that it is around 2.7 billion years old. it also serves as the foundation of evidence that it was the place where australian continent began to form.

how the structure of wave rock was created?

studies suggest that structure of wave rock was created when the surrounded area was started to weather due to which deposition of material started on the part of land which now contains wave rock.

the structure of wave rock is considered to be one of the best-known landforms in australia. at the height of around 15 cm, there can be found flared slopes which formulate the margins of hyden rock. it is now assumed by geologists that wave rock was created by subsurface water-induced weathering and not by glaciers, waves or wind.

due to deposition of material over the period of long time, the wave rock became tougher and tougher due to weathering from surrounding terrain. this makes it a physical evidence that supports   the evolution of earth due to chemical weathering.

hope it !