Analyzing Cell, Molecules, and Systems 2

Question 1

How many genes do humans have?

Answer 1

26,000

Question 2

There are 1 in ____ nucleotide differences between two human genomes

Answer 2

1,000

Question 3

What can SNP variants be?

Answer 3

neutral, pathogenic or predisposing

Question 4

What are SNPs?

Answer 4

single nucleotide polymorphisms

Question 5

What do endonucleases do?

Answer 5

cut DNA at specific sites

Question 6

In agarose gel electrophoresis, it differs from SDS page because _____

Answer 6

DNA is already charged

Question 7

What does ligase do?

Answer 7

glue DNA together

Question 8

What do plasmids do?

Answer 8

various functions, such as carry and replicate manipulated gene products

Question 9

What is a DNA library?

Answer 9

Every gene in the human body can be stored in bacteria indefinitely and propagated at anytime

Question 10

What is a cDNA clone?

Answer 10

DNA copy of mRNA, n introns and much smaller than original gene, requires viral enzyme

Question 11

Genes vs gene products

Answer 11

Genes: whole genome, intron and exon

Gene products: no introns, just coding DNA

Question 12

What does polymerase chain reaction (PCR) do?

Answer 12

amplify isolated DNA regions

Question 13

What is the purpose of PCR?

Answer 13

• earlier detection of microorganisms: HIV, bacterial and fungal infections
• detection fo specific genetic mutations

Question 14

What is the process of PCR?

Answer 14

ds DNA obtained
denatured to ss DNA
primers complement sequences that flank each end of DNA in 3-5’ direction
primers anneal
add deoxy nucleotide triphosphate (dNTPs) - all 4
Taq polymerase synthesizes copy of DNA by extending the primers on both ends, DNA doubles in each cycle

Question 15

What are the advantages to PCR?

Answer 15

very small amount of template DNA needed. 10^9 fold amplification from trace amounts of DNA

Question 16

What are the disadvantages to PCR?

Answer 16

need to know the sequence of the flanking DNA for primer design, error prone, amplification of contaminating DNA

Question 17

What is quantitative PCR (qPCR)?

Answer 17

used to quantify copy number of a specific gene in two or more samples in real time

Question 18

What does qPCR have along with primers?

Answer 18

a probe which fluoresces only in presence of the PCR product

Question 19

What is qPCR used for?

Answer 19

detect levels of infectious agent

determine levels of gene expression

Question 20

What are detections of variation in DNA sequences used for?

Answer 20

forensics

diagnostics (newborn screening, genetic carriers, etc)

Question 21

What is restriction fragment length polymorphism (RFLP)?

Answer 21

When difference in genome occurs in recognition sequences for restriction enzymes, the pattern on the gel is different
DNA fingerprinting

Question 22

What are variable number of tandem repeats (VNTR)?

Answer 22

pattern of short tandem repeats occurs in genome but varies in individuals
VNTR isolate from genomic samples by flanking restriction sites or through PCR
useful in identification and severity of inherited diseases

Question 23

What are DNA microarrays used for?

Answer 23

determine overall change in gene expression between two samples