Chapter 17

Question 1

Recombinant DNA

Answer 1

Single DNA molecule made from 2 different sources

Question 2

Restriction enzymes

Answer 2

recognize specific sequences of DNA and act as nuclease to cleave the DNA. 3 types, only type II cleaves at precise locations. Recognition sites are palindromes

Question 3

Sticky ends

Answer 3

DNA is cut at same base pair on either strand, produces staggered cuts (short, unpaired sequences aka overhangs). Allows DNA molecule from different source to be easily joined together.

Question 4

Restriction site/Recognition sequence

Answer 4

specific sequence of bases recognized and cut by an enzyme. 4 to 12 base pairs long,

Question 5

Gel electrophoresis

Answer 5

Made of agarose or polyacrylamide. Uses electrical field to separate negatively charged DNA molecules based on size and purify/isolate DNA fragments.

Strong negative change from phosphate backbone causes migrate toward positive pole. Gel slows movement of molecules base on size: larger move slower

Question 6

Polymerase Chain Reaction

Answer 6

Mimics processes of DNA replication to produce millions of copies of DNA sequence without need for molecular cloning

Steps:
1. Denaturation: heat is used to separate strands of double-stranded DNA
2. Annealing of primers: DNA is cooled, primers provide 3’ OH required for elongation by DNA polymerase
3. Synthesis: DNA polymerase makes new DNA

Requires template DNA, primers, nucleotides, and thermostable DNA polymerase

Question 7

Plasmids

Answer 7

DNA genetic elements (non-living) that carry genes that benefit an organism.

Question 8

Vectors

Answer 8

plasmids used as recombinant DNA tools to deliver genes to cells

Question 9

Reporter systems

Answer 9

Methods to detect transfected cells

Question 10

DNA Fingerprinting

Answer 10

Restriction fragment length polymorphism (RFLP analysis). Takes advantage of short, repeated sequences that vary among individuals. Primers flank region containing STR and amplify STR-containing region.

Question 11

Short tandem repeats (STRs)

Answer 11

simple sequence DNA segments within intron region, 1-13 bp segments that are repeated. Nucleotide sequence within STRs do not vary, but number of repeats vary amongst individuals (polymorphism)

Question 12

reporter gene

Answer 12

gene that researchers attach to regulatory sequence of another gene of interest

Question 13

DNA probe

Answer 13

Single-stranded DNA sequence used to search for complementary sequence in sample genome. Use to identify gene in a clone in a library