Chapter 9 Power Notes Answer Key
Section 9.1
Collected from—bacteria
Used for—cutting DNA
Cut DNA at—specific nucleotide sequences (restriction sites)
Can leave—blunt ends (straight cuts) or sticky ends (staggered cuts with free
nucleotides)
1. Restriction sites
Gel electrophoresis—separates DNA fragments based on size; smaller fragments travel
farther in a certain amount of time than larger fragments
Restriction maps—fragment sizes between restriction sites; do not show anything about
genes or DNA sequence
Section 9.2
PCR—technique that quickly copies a desired segment of DNA
1. temperature increased to separate DNA
2. temperature lowered and primers bind to each strand, bracketing the desired
segment of DNA
3.
temperature increased; polymerases make new strands of DNA
PCR amplifies—every cycle doubles the number of strands of DNA
Section 9.3
DNA fingerprinting
Based on—noncoding regions of DNA; number of nucleotide repeats in particular parts
of the genome; a person’s molecular identity; a type of restriction map using gel
electrophoresis
Person B—fragments at 2, 3, 4, 5
DNA fingerprints and probability—by investigating several parts of the genome, it is
very unlikely that two people would randomly share identical numbers of repeats
(multiplying each separate probability to find the total probability of a match)
Uses—criminal cases; immigration; paternity; studying biodiversity; identifying species;
tracking GM crops
Section 9.4
Cloning in nature—binary fission, some plants; some simple animals
Mammals—nuclear transfer; low success rate; Dolly the sheep first clone of adult
mammal
Potential and controversy —could be used in medical treatments; save endangered
species; bring back extinct species; low success rate; decrease biodiversity
Genetic engineering—changing an organism’s DNA to give the organism new traits
Recombinant DNA—DNA with genes from more than one organism; genes often
inserted into bacterial plasmids
Transgenic bacteria—have plasmid with recombinant DNA; used to make human insulin
Transgenic plants—bacteria with recombinant DNA infect plants; used to make crops
