AP Bio Chapter 20

Which of the following problems with animal cloning might result in premature death of the clones?

• use of nuclear DNA as well as mtDNA

• the indefinite replication of totipotent stem cells

• use of pluripotent instead of totipotent stem cells

• abnormal gene regulation due to variant methylation

Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning, there is a wider divergence of opinion. Which of the following statements provides a likely explanation?

• Cloning to produce embryonic stem cells may lead to great medical benefits for many.

• The use of adult stem cells is likely to produce more cell types than the use of embryonic stem cells.

• Cloning to produce stem cells relies on a different initial procedure than reproductive cloning.

• Cloning to produce embryonic stem cells may lead to great medical benefits for many.

Which of the following statements correctly describes one of the main differences between embryonic stem cells and adult stem cells?

• Embryonic stem cells can give rise to all cell types in the organism, and adult stem cells cannot.

• One aim of using embryonic stem cells is to provide cells for repair of diseased tissue.

• Embryonic stem cells can continue to reproduce for an indefinite period, and adult stem cells cannot.

• Embryonic stem cells only differentiate into only eggs and sperm, and adult stem cells differentiate into any type of cell.

Which of the following statements describes one of the technical reasons why gene therapy is problematic in humans?

• Most cells with an engineered gene do not produce gene product.

• Transferred genes may not have appropriately controlled activity.

• mRNA from transferred genes cannot be translated.

• Cells with transferred genes are unlikely to replicate.

Which of the following characteristics of short tandem repeats (STRs) DNA makes it useful for DNA fingerprinting?

• The number of repeats is highly variable from person to person or animal to animal.

• Every racial and ethnic group has inherited different short tandem repeats.

• The sequence of DNA that is repeated varies significantly from individual to individual.

• The sequence variation is acted upon differently by natural selection in different environments.

Which of the following information or processes does gene therapy require?

• he ability to express the introduced gene at any time in the tissue site within the patient

• the knowledge and availability of the defective gene but not the normal allele

• the ability to introduce a defective allele into a patient

• the ability to introduce the normal allele into the patient

In DNA technology, the term vector can refer to

• a SNP marker.

• a plasmid used to transfer DNA into a living cell.

• the sticky end of a DNA fragment.

• the enzyme that cuts DNA into restriction fragments.

Which of the following tools of DNA technology is incorrectly paired with its use?

• reverse transcriptase—production of cDNA from mRNA

•   DNA ligase—cutting DNA, creating sticky ends of restriction fragments

• DNA polymerase—polymerase chain reaction to amplify sections of DNA

• electrophoresis—separation of DNA fragments

The final step in a Sanger DNA sequencing reaction is to run the DNA fragments on a gel. What purpose does this serve?

•   It changes the length of the DNA fragments.

• It separates DNA fragments based on their charge.

• It separates DNA fragments generated during the sequencing reaction based on one- nucleotide differences in their size.

•   It adds ddNTP to the end of each DNA fragment.

Which of the following enzymes was used to produce the molecule of DNA in the figure?

• a restriction enzyme (endonuclease)

• RNA polymerase

• ligase

• DNA polymerase