ch 14

how many hydrogen bonds are formed between adenine and thymine in the double DNA helix?

- 2

x ray diffraction was used to determine that the diameter of a DNA molecule is

- 2nm

how many hydrogen bonds form between cytosine and guanine in the DNA double helix?

- 3

a segment of DNA has the sequence 5' ATGCCC 3' the complementary sequence would be

- 5' GGGCAT 3'

the purpose of the Hershey chase experiments was to determine whether a bacteriophage injected ____ or _____ into bacteria

- DNA - protein

a chromosome is primarily composed of

- DNA - proteins

which enzyme covalently links nucleotides together

- DNA polymerase

which of the following facilities the reversal of damage to our heredity material before a permanent mutation can occur

- DNA repair systems

match the function of each DNA polymerase in E. coli

- I - acts on the lagging strand to remove primers and replace them with the DNA II - not involved in replication but used for DNA repair III - the main replication enzyme

i order to purify the genetic material Avery. macLeod, and McCarty used which enzymes in their experiments?

- RNA digesting enzymes - protein digesting enzymes - DNA digesting enzymes

choose all the characteristics of the transforming substance isolated by Avery, Macleod, and McCarty

- RNA digesting enzymes did not affect its transforming ability - protein digesting enzymes did not affect its transforming ability - DNA digesting enzymes destroyed its transforming ability - the elemental composition of the substance was very similar to that of DNA

chargaffs rule A equals ____ and C equals ____

- T - G

the DNA fibers Franklin used in her x-ray diffraction studies came from

- Wilkins

the DNA structure proposed by Watson and Crick involves

- a helical structure - a sugar phosphate backbone - 2 grooves (major and minor)

the term used to describe 2 DNA strands that run in opposite directions from each other is

- antiparallel

DNA's phosphodiester ____ is composed of sugars and phosphates

- backbone

how are the origins of replication adjusted in eukaryotic cells, so that early in the embryonic development of eukaryotic organisms DNA can be replicated faster?

- cells can increase the number of origins used in early development

telomeres are related to

- cellular aging

different models for DNA replication include?

- conservative replication - semiconservative replication - dispersive replication

the interaction of 2 strands of DNA via hydrogen bonds is the

- double helix

which of these are part of the Watson- Crick model?

- each DNA molecule is composed of 2 strands that run anti parallel - each DNA molecule is composed of 2 phosphodiester strands

which cells have more than one origin of replication

- eukaryotes

this type of primase is a combination of RNA polymerase and DNA polymerase that makes short RNA and then extends them with DNA to produce the final primer

- eukaryotic

a bacteriophage contains

- genetic material - a protein coat

indicate the 4 nitrogenous bases used in DNA

- guanine - cytosine - thymine - adenine

the enzyme ___ uses ATP to unwind the DNA template

- helicase

the experiments with radioactively labeled phage that showed that DNA was the genetic material were performed by

- hershey and chase

the primary purpose of the Meselson and the Stahl experiments was to determine

- how DNA replicates

on this strand, the removal of the last primer leaves a gap that cant be primed at the ends of the chromosome

- lagging

as the lagging strand is being synthesized, adjacent Okazaki fragments are joined by the enzyme DNA ____

- ligase

DNA replication in eukaryotic cells is complicated by the fact that eukaryotic cells have

- linear chromosomes

which of the following types of streptococcus pneumonia did griffith inject into mice

- live - rough - smooth - heat killed

DNA primase

- makes primer about 10-20 nucleotides in length - makes a primer of RNA complementary to the DNA

radiation, UV light, x- rays, and chemicals in the environment can cause mutations in DNA and are therefore referred to as ____

- mutagens

select all of the following that are component of a nucleotide

- nitrogenous base - phosphate group - sugar

during semiconservative DNA replication

- one of the strands in each new double helix comes from the original molecule, and one is newly synthesized

in DNA, consecutive nucleotides are linked via ___ bonds, which are made between the 5' phosphate and 1 nucleotide and the 3' ____ group of another nucleotide

- phosphodiester - hydroxyl

the enzyme ____ can repair UV damage by binding to a thymine dimer and cleaving it, therefore restoring 2 thymines

- photolyase

all DNA polymerase require a short strand of DNA or RNA called a ___ to begin their synthesis

- primer

function of telomeres

protect the ends of chromosomes

order the steps in excision repair from first to last

- recognition of damage - removal of the damaged region - resynthesis using the information in the undamaged strand as a template

DNA replication that leads to the production of double helices with 1 parental strand and 1 newly synthesized strand consistent with

- semi conservative replication

telomerase uses which of the following as a template

- short internal RNA

bacterial replication ( for ex. E. coli) begins at

- single origin

which of the following enzymes involved in DNA replication are found at the replication fork in all 3 types of cells (bacterial, archaeal, and eukaryotic)?

- sliding clamp - clamp loader - helicase - polymerases - primase

list several differences in prokaryotic and eukaryotic replication

- structure of chromosome (linear vs circular) - number of origins of replication - complexity of enzymology

the enzyme ____ contains a small internal piece of RNA, which is used as a template to extend the end of a linear DNA molecule

- telomerase

____ are short protective repeats of DNA on the ends in eukaryotic chromosomes which are generated by the enzyme ____

- telomeres - telomerase

which 3 are required for DNA replication

- template - nucleotides - polymerase

list the 3 phases of DNA replication

- termination - elongation - initiation

DNA replication in E. coli ends at a site called the ___

- terminus

if normal fibroblast cells are grown in cell culture and the enzyme telomerase is introduces in them

- the cells show an increased lifespan

Griffith's experiments demonstrated the ____ principle

- transformation

phages are a type of ____ that infect ____ cells

- virus - bacteria

place the steps of the experiment that Hershey and chase performed to demonstrate that DNA was the genetic material of bacteriophages in the correct order

1 bacteriophages were grown on media containing radioactive material 2 bacteriophages were allowed to infect bacteria 3 a blender was used to remove bacteriophages from cell surfaces 4 the sample was centrifuged 5 radioactively was measured

match each element of the nucleotide to the sugar carbon atom it is attached to

1' nitrogenous base 3' OH group 5' phosphate group

match enzymes involved in DNA replication

helicase- causes DNA strand separation at the origin of replication - topoisomerase- relives coiling in DNA strands ahead of the replication fork - primase- makes a 10-12 bp complementary primer to the DNA - polymerase- attaches a nucleotide to the 3' end of the DNA strand