maintaining the genome

Question 1

which protein does DNA combined with and what does this form

Answer 1

histones
nucleosomes

Question 2

what is the basic building block of DNA

Answer 2

nucleotide

Question 3

what do nucleotides consist of

Answer 3

sugar
phosphate
base

Question 4

what part of the nucleotide makes up the backbone of the double helix

Answer 4

sugar and phosphate

Question 5

what is the sugar present in DNA? how many carbons?

Answer 5

2-deoxyribose, 5 carbons

Question 6

4 bases? 2 different types?

Answer 6

cytosine and thymine - pyrimidines
adenine and guanine - purines

Question 7

which bases pair

Answer 7

cytosine and guanine
thymine and adenine

Question 8

what is the name for just the sugar and the base

Answer 8

nucleoside (not nucleotide)

Question 9

which prime end is the start of the chain? which is the end?

Answer 9

5’ is start
3’ is end

Question 10

what is DNA and its associated histones called

Answer 10

chromatin

Question 11

how many histone proteins are present in a nucleosome? what are their names?

Answer 11

8 proteins in a nucleosome, 2 of each:
H2A
H2B
H3
H4

Question 12

what extends out from a nucleosome and what is their significance

Answer 12

long amino acid tails from each histone.
subject to reactions that control chromatin structure

Question 13

number of chromosomes in humans

Answer 13

23 pairs (22 pairs of autosomes, 1 pair of sex chromosomes)

Question 14

where does DNA synthesis start

Answer 14

DNA origin

Question 15

what seperates DNA strands

Answer 15

initiator proteins

Question 16

what synthesizes new strands of DNA

Answer 16

DNA polymerase

Question 17

2 different strands in DNA replication

Answer 17

leading strand and lagging strand

Question 18

what occurs in the lagging strand

Answer 18

short fragments of DNA strands are created (okazaki fragments) and are joined by DNA ligase

Question 19

what does DNA polymerase bind to to start a strand

Answer 19

primase (an RNA polymerase)

Question 20

what is primase removed by

Answer 20

nuclease activity

Question 21

what helps unwind the double helix

Answer 21

DNA helicase

Question 22

DNA mismatch repair?

Answer 22

newly synthesised DNA removed, DNA polymerase bind to 3’ end of new strand and replaces section

Question 23

what can cause DNA damage

Answer 23

replication errors
UV light
chemicals
radiation
cellular metabolism

Question 24

differences between mitochondrial and nuclear DNA

Answer 24

circular not linear
inheritance is only maternal

Question 25

PCR steps?

Answer 25

strands heated causing them to separate. cooled to add primers. DNA synthesis occurs. each cycle doubles amount of DNA