Selective breeding involves taking advantage of the organism’s best trait in order to produce offspring with desirable traits and pass it on to the next generation, whereas genetic engineering and inducing mutations produce random and unpredictable results.

A. I only

A plasmid is a small and circular DNA molecule that is found in a bacterial cell. It can accept foreign DNA and has the ability to replicate independently since it is located outside of the bacterial chromosome. On the other hand, since animal cells are larger than a bacterial cell and they have a nucleus, they do not have plasmids.

E. in animal cells

Since the bacterial cell has recombinant plasmids, which contains the human gene, it is usually cultured and treated with an antibiotic after a transformation. Only the cells which are transformed successfully will survive because they are carrying the resistance gene.

E. I, II, and III

The human gene that is inserted into the plasmid contains genetic information to make a protein.

B. II only

A plasmid is used to transfer new genes to a plant cell. The bacterial cell inserts itself to the DNA of the plant cell to complete the transformation.

B. plasmid

During a polymerase chain reaction, smaller segments of DNA are being copied.

C. Polymerase chain reaction

The assembly of short sequences of DNA can be performed by a laboratory equipment known as a **DNA synthesizer**. This machine can synthesize DNA as defined by the researcher.

Since DNA synthesizers can produce custom-made DNA, it can be used to synthesize specific DNA molecules that can be used to treat a variety of genetic disorders by repairing the DNA.

E

Separating the DNA involves gel electrophoresis. In electrophoresis, DNA, RNA, and proteins are separated according to their sizes. In this way, the scientists can study the sequence of DNA and RNA, and compare the gene composition of different organisms.

A. Gel electrophoresis

The graph shows an uphill pattern that indicates the values on x-axis, which is the cycle number, and the values on y-axis, which is the number of accurate copies of original DNA templates, have a positive relationship. As the cycle number increased, the number of accurate DNA copies also increased. Therefore, the growth was at an exponential rate during cycles 18 to 26.

A. PCR produced accurate copies of template DNA at an exponential rate.

Based on the graph, the increase rate during cycles 26 to 28 was slower than the previous cycles. This indicates that the DNA polymerase loses activity and causes the rate of reaction to slow down.

B. the rate of reaction slowed down