Nucleic Acid

Question 1

How many chromosomes are there in a normal cell?

Answer 1

46 (23 pairs)

Question 2

Name 2 cells that do not have the usual number of chromosomes

Answer 2

Sex cells

Red blood cells

Question 3

What are chromosomes made from ?

Answer 3

DNA found in the nucleus

Question 4

What is a histone?

Answer 4

Protein + DNA

found in chromosomes

Question 5

Describe nuclear division

Answer 5

nucleus divides ( mitosis and meiosis)

Question 6

Describe Cytokinesis

Answer 6

Follows nuclear division and is the process by which the whole cell divides

Question 7

What is the process by which the whole cell divides?

Answer 7

Cytokinesis

Question 8

Describe the three components of a individual nucleotide

Answer 8

Phosphate group
Pentose sugar
Nitrogen-containing organic base

Question 9

Name the 5 organic bases

Answer 9

Adenine
Thymine
Cytosine
Guanine
Uracil

Question 10

How is a mononucleotide formed?

Answer 10

By multiple condensation reactions

Question 11

Name the bond between the phosphate group and pentose sugar on separate nucleotides

Answer 11

phosphodiester bond

Question 12

What is a phosphodiester bond ?

Answer 12

bond between the phosphate group and pentose sugar on separate nucleotides

Question 13

What does RNA stand for ?

Answer 13

Ribonucleic acid

Question 14

What is the structure of RNA?

Answer 14

Single short polynucleotide chain
pentose sugar = ribose sugar
Adenine Uracil Cytosine Guanine

Question 15

List 3 examples of RNA

Answer 15

One is involved in protein synthesis
One transfers genetic material from DNA to the ribosomes
Ribosomes are made up of proteins and RNA

Question 16

What is transcription?

Answer 16

a particular segment of DNA is copied into RNA (especially mRNA) by the enzyme RNA polymerase

Question 17

What is translation ?

Answer 17

ribosomes in the cytoplasm or ER synthesize proteins

Question 18

What is the structure of DNA?

Answer 18

Deoxyribose sugar
Adenine Thymine Cytosine Guanine
2 polynucleotide molecules arranged like a ladder } double helix

Question 19

Base pairs are _____

Answer 19

complementary

Question 20

In what year was the DNA of DNA discovered and by whom?

Answer 20

1953
James Watson and Francis Crick
Rosalind Franklin

Question 21

Adenine binds with ______

Answer 21

Thymine

Question 22

Thymine binds with _______

Answer 22

Adenine

Question 23

Cytosine binds with _______

Answer 23

Guanine

Question 24

Guanine binds with _______

Answer 24

Cytosine

Question 25

What bonds form between base pairs?

Answer 25

Hydrogen

Question 26

Why is DNA stable?

Answer 26

Phosphodiester backbone protects organic baes inside helix from chemical reactions H-Bonds between organic base pairs ( CG> AT ) 'Base stacking'= interactive forces

Question 27

Name the function of DNA

Answer 27

It is the hereditary material responsible for passing genetic information from cell to cell and generation to generation.

Question 28

How is DNA adapted to carry out its function?

Answer 28

Very stable structure that only rarely mutates when passing from generation to generation Hydrogen bonds between base pairs can easily be separated during DNA replication and protein synthesis Extremely large molecule so it carries a lot of information base pairs within helical cylinder are protected from corruption base paring = DNA can replicate and transfer information as mRNA

Question 29

Name the backbone

Answer 29

deoxyribose-phosphate

Question 30

The 2 strands of DNA are ___

Answer 30

anti-parallel

Question 31

5' = | 3' =

Answer 31

5 prime = phosphate group | 3 prime = hydroxyl group

Question 32

Nucleic acid can only be synthesised in what direction ?

Answer 32

5-3 direction

Question 33

Compare DNA and RNA for their differences

Answer 33

``` DNA double-stranded/double helix and mRNA single-stranded; DNA (very) long and RNA short; Thymine/T in DNA and uracil/U in RNA; Deoxyribose in DNA and ribose in RNA; DNA has base pairing and mRNA doesn’t/ DNA has hydrogen bonding and mRNA doesn’t; DNA has introns/non-coding sequences and mRNA doesn’t ```