Chap 12 Mastering Biology Assignment

Restriction enzymes __________________________.

cut DNA at specific nucleotide sequences

The gel shown above includes a DNA ladder that can be used to estimate the sizes of DNA molecules. The ladder increases in 100 nucleotide increments, from 100 to 700. Four DNA molecules have been separated on this gel (labeled A to D). What is the approximate size of DNA molecule A?

350 nucleotides

Which of the following is the best definition for recombinant DNA?

DNA that includes pieces from two different sources

The sticky end of the DNA restriction fragment shown here will pair with a DNA restriction fragment with the sticky end _____.

The matching of sticky ends follows the rules of specific base pairing.

What part of a nucleotide is negative?

The phosphate group of a nucleotide, represented here as a yellow ball, contains a negative charge.

Which of these DNA molecules is the shortest?

The shorter the DNA molecule, the farther it moves.

Makes a large sample of DNA from a small sample of DNA

This machine is a PCR machine. PCR is a method for amplifying DNA

When is PCR particularly applicable?

When there are small quantities of DNA to analyze

Which of the following is an example of a transgenic organism?

a bacterium with human gene for producing insulin

In recombinant DNA experiments, __________ is used to cut pieces of DNA and __________ joins the resulting fragments to form recombinant DNA.

a restriction enzyme ... DNA ligase (Restriction enzymes cut DNA molecules at specific points; in some cases, the restriction fragments have sticky ends that can base-pair with complementary sticky ends. The joined segments are then covalently fused by DNA ligase.)

Which of the following is a genetically modified organism?

an organism carrying a gene that was acquired by artificial means

Which of the following best defines the term "transgenic organism"?

an organism containing a gene from another species

What is recombinant DNA technology?

combining genes from different species (Recombinant DNA technology involves combining genes from two sources, even different species, into a single chromosome or individual.)

The unpaired nucleotides produced by the action of restriction enzymes are referred to as _____.

sticky ends

In a PCR reaction, the strands of DNA are first separated by ___.

heating

The diagram below summarizes ________.

human gene therapy

In gel electrophoresis DNA molecules migrate from _____ to _____ ends of the gel.

negative ... positive (An electrical current is generated across the gel, and DNA molecules migrate from the negative end toward the positive end.)

You can use this DNA fingerprinting information to make a judgment about maternity because ________.

of the position of the bands in the gel

A supplemental appendix is to a book as a ____________ is to a bacterial chromosome.

plasmid

Human insulin is produced in large quantities by __________.

recombinant E. coli bacteria grown in large fermentation vats (This recombinant bacterium expresses the human insulin gene.)

What is the correct sequence of events that occur in a PCR reaction?

separation of DNA strands; addition of primers; use of DNA polymerase to produce second strand of DNA

Gel electrophoresis separates pieces of DNA based on _________.

size

DNA polymerase is a heat-sensitive enzyme. What is one thing that would need to be considered concerning the activity of this enzyme in PCR when the temperature is heated during each cycle to separate the DNA strands?

that the DNA polymerase could be denatured

The following figure shows that gel electrophoresis can be used to separate repetitive DNA sequences. Gel electrophoresis separates DNA fragments because ________.

the DNA fragments have different lengths

The process of accurately amplifying a sample of DNA is called __________________________.

the polymerase chain reaction