Biology DNA

Question 1

What are the 3 characteristics of DNA?

Answer 1

1. able to store information
2. stable replication
3. undergo rare changes

Question 2

Purine Nucleotides are?

Answer 2

double ringed

Question 3

Pyrimidine nucleoties are?

Answer 3

single ringed

Question 4

what does DNA helicase do?

Answer 4

separates double-stranded DNA into single strands

Question 5

SSB-single stranded binding protien

Answer 5

binds to single-stranded DNA and prevents to from re-forming a double helix

Question 6

DNA primase does what?

Answer 6

synthesizes short RNA primes

Question 7

DNA polymerase does what?

Answer 7

synthesize DNA in the leading and lagging strands, removes RNA primers, filling the gaps with more DNA and proof-reads newly made DNA

Question 8

parents strands are….

Answer 8

antiparallel to each other

Question 9

DNA replication is a semiconservative process because?

Answer 9

each daughter strand contains a old strand from the parental DNA

Question 10

DNA always occurs in the…

Answer 10

5 to 3

Question 11

prokaryotic DNA replication….

Answer 11

can occur in two directions at once because the DNA molecule is circular

Question 12

prokaryotic DNA is….

Answer 12

a single looped chromosome

Question 13

prokaryotic DNA must be….

Answer 13

replicated before the cell can divide

Question 14

what are the steps to prokaryotic DNA replication?

Answer 14

1. the strands sperate and unwind
2. a DNA enzyme binds to each side of the opening
3. two DNA polymerase meet at the termination region and replication is stopped.
   - two chromosomes are separated

Question 15

Eukaryotic DNA replication brings

Answer 15

along the length of the linear chromosome

Question 16

genetic coding is degenerate

Answer 16

most amino acids have more than one codon

Question 17

redundancy of the code helps…

Answer 17

protect against potentially harmful mutations

Question 18

genetic code is unambigous

Answer 18

each triplet codon has only one meaning

Question 19

the code has how many start and stop signals

Answer 19

one start signal and 3 stop signals

Question 20

what is the start signal?

Answer 20

AUG

Question 21

what are the stop singals?

Answer 21

UAA / UGA / UAG

Question 22

transcription is

Answer 22

DNA to RNA (writing across)

Question 23

translation is

Answer 23

RNA to polypeptide (carry across)

Question 24

what are the steps to transcription

Answer 24

1. RNA polymerase attaches to a region of DNA promoter (defines the start, direction and the strand to be transcribed)
2. RNA polymerase reads down the DNA strand 5’ to 3’ and stops once it reaches a DNA sequence.
3. RNA polymerase stops transcribing and releases the mRNA transcript.

Question 25

what are the steps to translation

Answer 25

1. initiation- brings all the translation components together. tRNA pairs with the start codon (AUG)
2. a polypeptide increases one amino acid at a time
3. the polypeptide and assemble components are separated