Chapter 16: Molecular Basis of Inheritance

Question 1

Antiparallel elongation

Answer 1

the process by which DNA polymerases can only travel along the DNA strand from the 5 prime end to the 3 prime end

Question 2

Telemorase

Answer 2

enzyme that creates/attaches the telomere base sequences to the ends of DNA strands to fill in the gaps left during replication (each replication causes the strand to get shorter and shorter)

Question 3

(nucleotide) excision repair

Answer 3

nuclease enzyme cuts out and removed damaged stretch of DNA, then DNA polymerase replaces the removed nucleotide with the correct one

Question 4

Origins of DNA replication

Answer 4

Particular sites on DNA where replication begins

Two strands open up in a replication ‘bubble’

Question 5

(Bacterio)phage

Answer 5

Viruses that infect bacteria

Question 6

Mismatch REpair

Answer 6

when enzymes other than DNA polymerase can correct nucleotides

Question 7

DNA Polymerase

Answer 7

enzyme that catalyzes the elongation of new DNA at a replication fork

also proofreads newly made DNA & replaces incorrect nucleotides

Question 8

heterochromatin

Answer 8

highly condensed chromatin that exists during interphase

exps. telomeres and centromeres

Question 9

Chargaff’s rule (from before we knew about the double helix)

Answer 9

1. base composition of DNA varies between species

2. In any species, the number of adenines and thymines are equal, and the number of cytosines and guanines are equal.

Question 10

Helicases

Answer 10

enzymes that untwist the double helix at the replication forks

Question 11

(Debunked) Conservative model of DNA replication

Answer 11

original double-stranded helix somehow codes for a completely new double helix while still maintaining the original double helix.

Question 12

Transformation

Answer 12

Changes in genotype and phenotype d/t assimilation (like when Griffith put dead toxic virus DNA in live harmless virus and the harmless virus became toxic)

Question 13

pyramidines

Answer 13

The 2 nitrogenous bases whose molecule consists of 1 ring (cytosine and thymine)

Purines pair up with pyramidines

Question 14

DNA ligase

Answer 14

holds together the Okazaki fragments by joining their sugar-phosphate backbone

Question 15

DNA pol III

Answer 15

synthesizes the leading strand of DNA during replication

Question 16

Nuclease

Answer 16

enzyme that cuts out nucleotide mistakes in DNA strands during replication

Question 17

Single strand binding proteins

Answer 17

bind to a strand of the unzipped DNA (during replication) to stabilize it/keep it from snapping back to the other parent strand

Question 18

DNA Replication (3 steps)

Answer 18

1. Orgins form to initiate replication
2. Synthesize the leading strand
3. Synthesize the lagging strand

Question 19

Telomere

Answer 19

the ends of DNA molecules (made of special nucleotide sequences)

reduces/slows the rate of erosion/shortening of genes at the end of the DNA molecules

Question 20

euchromatin

Answer 20

loosely condensed chromatin

Question 21

Antiparallel strands (of DNA)

Answer 21

describes that fact that DNA lines up is 5 to 3 prime ends in an antiparallel fashion with its 3 to 5 prime end

Question 22

Virus

Answer 22

DNA or RNA enclosed in a protective coat

Coat usually made of protein

Question 23

Alfred Hershey and Martha Chase experiment

Answer 23

Used T2 viruses to infect e. coli to prove DNA was the genetic material

Made T2 protein and DNA radioactive, then infected bacteria cells with them, one at a time. Protein did not go into the host cell, but DNA did

Question 24

nucleiod

Answer 24

the place in bacteria where DNA is coiled together (instead of in a nucleus like with eukaryotes)

Question 25

Maurice Wilkins and Rosalind Franklin

Answer 25

used x-ray crystallography to create the photo of DNA’s double helix that Watson and Crick used

Question 26

Waston and Crick

Answer 26

Used Rosalind Franklin’s DNA photo to deduce that:

1. DNA made of 2 outer sugar-phosphate backbones
2. DNA has paired nitrogenous bases in its interior
3. Purines only match with pyrimidines

Question 27

(DNA) replication fork

Answer 27

Y shopped region where DNA strands are elongating

Question 28

Lagging strand

Answer 28

The DNA strand that DNA polymerase synthesizes, working away from the replication fork

Question 29

Leading strand

Answer 29

The DNA strand that DNA polymerase continuously synthesizes, moving TOWARDS the replication fork

Question 30

Frederick Griffith experiment

Answer 30

Proved DNA was the genetic material

Killed mice:
put dead toxic virus DNA in live harmless virus and the harmless virus became toxic

Question 31

Purines

Answer 31

The 2 nitrogenous bases whose molecule consists of 2 rings (adenine and guanine)

Purines pair up with pyramidines

Question 32

Primase

Answer 32

enzyme that creates primer strand (about 10 nucleotides long)

can start an RNA strand from scratch and adds RNA nucleotides at one time using parental DNA as a template,

Question 33

Semi-conservative model (of DNA replication)

Answer 33

When DNA unzips and duplicates to make 2 dgt strands, each strand will have one old/original (“conserved”) and one newly made strand

Question 34

(Debunked) Dispersive model of DNA replication

Answer 34

original double-stranded helix is broken apart into individual nucleotides; original nucleotides recombine with new nucleotides to make new double helices that are a combo of old and new nucleotides

Question 35

Topoisomerase

Answer 35

corrects “overwinding” ahead of replication forks by breaking, swiveling, and rejoining DNA strands

Question 36

Replication “bubble”

Answer 36

The place where a strand of DNA opens up for replication

Question 37

Mathew Meselson and Franklin Stahl experiments

Answer 37

Proved the semi-conservative model of DNA replication by inserting ‘heavy’ nitrogen into DNA, chopping it up, centrifuging it, and comparing the relative locations of the nitrogen in test tubes

https://www.khanacademy.org/test-prep/mcat/biomolecules/chromosomal-inheritance/v/evidence-that-dna-is-genetic-material-1