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Flashcards in Chapter 16 Deck (32):
1

In Fredrick griffiths experiment why did the mice injected with both heat killed s cells and living r cells die, when neither one alone was fatal?

The r bacteria was transformed into an s bacteria by an unknown heritable substance

2

A change in genotype and phenotype due to the assimilation of external dna by a cell

Transformation

3

Viruses that infect bacteria

Bacteriophages

4

Hershey and chase created phages with radioactive protein and phages with radioactive DNA. Which one resulted in radioactive bacteria? Why?

DNA
it functions as the genetic material of phage t2

5

What year did Watson crick publish their structure for DNA

1953

6

Chargoffs rule

A=t
C=g

7

Two strands of DNA w double helix and sugar-phosphate backbone

See chapter notes

8

Nucleotide pairs

C & G
A & T

9

DNA is replicated by base pairing to a template strand. If you missed class and copied your friends notes, who's notes are acting as a template?

The friends

10

In a new DNA molecule ___ of the new double helix is made up of nucleotides from the previously existing molecule

Half

11

DNA replication can only begin at particular called

Origins of replication

12

Diagram of replication fork

See chapter notes

13

Unwinds and pulls apart the 2 DNA strands

Helicase

14

Prevents over winding

Topi isomerism

15

Builds primer (short RNA sequence to begin new strand)

Promise

16

Adds DNA nucleotides to 3' end of growing strand

DNA polymerase

17

DNA polymerase can only add nucleotides to an existing chain, so in order to initiate replication it requires a short chain of RNA called

Primer

18

Bc of the antiparallel structure of DNA, each single strand has a 3' end a

5' end

19

DNA polymerase can only add nucleotides to the ___ end of the growing new strand

3'

20

Elongation occurs in the direction away from the ___ end of the template strand and towards the ____ end of the template strand

5'
3'

21

The lagging strand cannot be but in one continuous piece, and must be pieces together as a series of segments called

Okazaki fragments

22

Each of these segments begins with a ____ made of RNA

Primer

23

A primer is eventually replaced with DNA by the enzyme ____

DNA polymerase

24

The segments are joined together into a continuous strand by the enzyme

DNA ligase

25

Mechanisms for minimizing errors in DNA replication

Proofreading by the enzyme DNA polymerase during replication
Removal and replacement of incorrect nucleotides during replication, in a process know as mismatch repair
Removal of a damaged DNA strand after replication is complete by the enzyme nuclease

26

The 5' end of the lagging strand consists of a primer made of

RNA

27

This primer cannot be replaced because DNA polymerase ____ add nucleotides to the 5' end of the strands

Cannot

28

With each replication, a linear chromosome becomes

Shorter

29

The end of each of our chromosomes consists of a chunk of nonsense DNA known as

Telomeres

30

In germ cells (cells that produce egg and sperm) this nonsense DNA is lengthened by the enzyme

Telomerase

31

What would happen if you had no telomerase in your germ cells?

Babies would be born w no telomeres - would be born already old

32

What would happen if you had telomeres in all of your cells?

More susceptible to cancer