Theme 1B

Question 1

What are the 3 components of DNA

Answer 1

Pentose sugar-ribose (RNA) or Deoxyribose (DNA)
Nitrogenous bases (purine or Pyrmidine
Phosphate

Question 2

What is the difference between ribose and deoxyribose

Answer 2

Given the name deoxy, deoxyribose is missing an oxygen on 2 prime c.arbon. Ribose on the other hand has an OH on the 2 prime carbon

Question 3

What is the difference between purine and pyridine ring

Answer 3

Purine has a double ring Adenine and guanine are purines that bind to N9 nitrogen
While Pyrmidine has a single ring cytosine, thymine and uracil are pyrimidine that bing to N1 nitrogen

Question 4

What is a nucleoside

Answer 4

molecules of a sugar and a base together

Question 5

What is deoxyribonuleoside

Answer 5

2-deoxyribose sugar+purine/ pyridine ring

Question 6

What is a nucleotide

Answer 6

A molecule containing a nitrogenous base a phosphate group and a pentose sugar

Question 7

Where is the phosphate group attached to the sugar

Answer 7

It is attached to the carbon 5 of ribose/deoxyribose sugar

Question 8

What is DNA

Answer 8

a polymer of deoxyribonucleotide

Question 9

What are the role of phosphodiester bonds in DNA

Answer 9

Nucleoyide monomers polymerize (attach to each other) using phosphodiester bond

Question 10

What role do covalent bonds play in DNA

Answer 10

Covalent bonds form between phosphate and C-3 and C-5 of two sugars forming pentose-phosphate backbone

Question 11

What makes a polynucleotide polar

Answer 11

because of 5 prime and 3 prime end

Question 12

Are DNA molecules negatively charged

Answer 12

YES

Question 13

What are the 3 characteristics of DNA

Answer 13

It is linear
Has a pentose phosphate backbone
Nitrogenous bases held the code since they are the only unique thing between individuals

Question 14

What is chargaffs rule

Answer 14

the percentage of purines is equal to the percentages of pyrimidines.
There is the same amount of c and gs
there is the same amount of a and t

Question 15

What was Rosalind franklins role in finding the structure of DNA(3)

Answer 15

she printed a photo of DNA and concludes that
Dna molecules are cyndrical and 2mm in diameter
0.34 periodicity suggest bases are stacked on top of each other
Helical structure of DNA

Question 16

What keeps two dna strands bonded together

Answer 16

hydgrogen bonding
at has two bonds
cg has 3 bond

Question 17

How can we denature DNA

Answer 17

under heat or alkali

Question 18

What is chromatin

Answer 18

regions of dna with its associated proteins on a chromosome

Question 19

What are plasmids

Answer 19

prokaryotes have one circular chromosome called plasmids

Question 20

Describe eukaryotic chromosomes

Answer 20

they are linear and enclosed in a nucleus

Question 21

What are the 3 components of eukaryotic chromosomes

Answer 21

1. Orgin of replication
2. Centromeres
3. Telomeres

Question 22

What is the origin of replication

Answer 22

DNA sequences along chromosome which initiate dna replication

Question 23

Centromere

Answer 23

DNA sequences required for correct segregation of chromosomes by directing formation of the kintochiore in which the biotic spindle attaches

Question 24

Telomeres

Answer 24

DNA sequences located at the end of the chromosome
Only needed for eukaryotes

Question 25

In humans which cells are haploid

Answer 25

sexually reproductive cells

Question 26

Why are some eukaryotes polyploid

Answer 26

They have huge cells and need lots of protein and genes +DNa are used to make atheist proteins

Question 27

What are the 3 reasons that dna is organized in chromosomes

Answer 27

1. Chromosomes compact dna so it can fit in nucleus 2. Chromosomal structure protects dna from damage 3. chromosomes can be easily separated and transmitted to each daughter cell during cell division

Question 28

What are histones

Answer 28

basic positively charges proteins that DNA winds around

Question 29

What is the Role of histone 1

Answer 29

binds to dna and nucleosomes causing nucleosomes to form coiled chromatin

Question 30

Nucleosome

Answer 30

ball of 4 different histones Dna wraps around nucleosomes

Question 31

Dna packing is uniform true or false

Answer 31

False

Question 32

What are euchromatin

Answer 32

regions have lower dna compaction and genes are actively expressed

Question 33

What are heterchromotain

Answer 33

regions of high dna compaction where gene expression is silenced. Proteins can't get in to turn genes on

Question 34

Consistutive heterochromatin

Answer 34

area where Dna always highly compacted centromemeres and subtelomeric regions

Question 35

Facatve heterochromatic

Answer 35

can switch to euchromatin depending on cell type and during development

Question 36

Which part of DNA have a negative charge

Answer 36

the phosphate group