Biology Chapter 12

Question 1

Explain how DNA profiling is used in criminal cases

Answer 1

DNA profiling can match DNA samples to determine whether somebody was at a crime scene or not.

Question 2

Recombinant DNA technology

Answer 2

Combining DNA from two distinct sources to make one DNA molecule.

• Used in genetic engineering

Question 3

Explain how recombinant DNA techniques are used to mass-produce a protein from an isolated gene.

Answer 3

The desired protein is transferred into a bacterium or yeast for rapid reproduction

Question 4

Describe the process of cloning genes using plasmids.

Answer 4

A piece of DNA is first spliced into a plasmid and joined with a gene of interest by DNA ligase

Question 5

Explain how restriction enzymes and DNA ligase are used to create recombinant DNA.

Answer 5

Restriction enzymes cuts the DNA into fragments, the new DNA is inserted, and DNA ligase recombines everything.

Question 6

POlymerase Chain Reaction

Answer 6

• is a technique to copy quickly and precisely a specific segment of DNA and
• can generate enough DNA, from even minute amounts of blood or other tissue, to allow DNA profiling.

Question 7

Short Tandem Repeat Analysis

Answer 7

Short tandem repeats (STRs) are short strands of DNA that are repeated at regular intervals in the genome.

STR analysis compares STR sequences at specific sites in the genome.

Question 8

Gel Electrophoresis

Answer 8

A process that helps compare DNA samples by separating them by size.

Question 9

Whole genome shotgun method

Answer 9

• genome is “blasted” into short pieces using restriction enzymes
• All fragments are cloned and sequence
• Specialized computer software maps them out

Question 10

Describe the types of organisms that have been the subject of recent sequencing efforts. Explain why these particular organisms have been examined.

Answer 10

Some examples are chimpanzees (mapped for their closeness to humans), duck-billed platypus (mapped for their uniqueness in the animal kingdom), and the potato (mapped for GMO possibilities)

Question 11

Describe the goals of the Human Genome Project. Explain why our genome presents a major challenge.

Answer 11

The goals of the Human Genome Project were:

• determine the nucleotide sequence of all the DNA in the human genome and
• identify the location and sequence of every gene.

Our genome presents a challenge because:

We have a very complex genome

Question 12

Explain how comparative genomics has been used to investigate acts of bioterrorism, track the spread of disease, and study evolutionary relationships.

Answer 12

• A regularly functioning RNA version of the mutated gene is inserted into a harmless virus
• The subject’s bone marrow is infected with the virus
• Viral DNA carrying the human gene inserts into cells’ chromosomes

Question 13

Describe the surprising results of DNA profiling of the human Y chromosome.

Answer 13

The Y chromosome is passed down intact from father to son, so you can learn quite a bit about history from it. Scientists have learned:

• nearly 16 million men currently living may be descended from Genghis Khan,
• nearly 10% of Irish men were descendants of Niall of the Nine Hostages, a warlord who lived during the 1400s, and
• the Lemba people of southern Africa are descended from ancient Jews.