9 Ass 5 pt 1 Nucleotides and Genetic Control

Question 1

A piece of double-stranded DNA containing 12x10^3 nucleotides is transcribed and translated to produce a single polypeptide. What is the maximum number of amino acids in this polypeptide?

Answer 1

2x10^3

Question 2

Are purines and pyrimidines the same size?

Answer 2

No, they’re different sizes

Question 3

How many hydrogen bonds does Adenine have with thymine and Uracil?

Answer 3

2

Question 4

Are the base pairs in a molecule of DNA of different lengths and widths?

Answer 4

No. Base pairs are of equal length and width

Question 5

How many rings does adenine have in its structure?

Answer 5

two

Question 6

How many rings does guanine have in its structure?

Answer 6

two

Question 7

How many rings does Uracil have in its structure?

Answer 7

one

Question 8

How many rings does thymine have in its structure?

Answer 8

one

Question 9

How many rings does cytosine have in its structure?

Answer 9

one

Question 10

Q4 fill in table

Answer 10

See written qp

Question 11

What is the carbohydrate in DNA

Answer 11

deoxyribose

Question 12

what is the carbohydrate in RNA?

Answer 12

Ribose

Question 13

Why are the two sugar-phosphate chains in a DNA molecule a constant distance apart?

Answer 13

Each purine base is linked to a pyrimidine base

Question 14

Which bases are pyrimidines?

Answer 14

Thymine, Uracil and cytosine

Question 15

Q10 what is 2?

Answer 15

ribose

Question 16

q10 How many hydrogen bonds in 3?

Answer 16

3 hydrogen bonds

Question 17

Q11 which mutated DNA would result in a polypeptide with 1 different amino acid?

Answer 17

CCA TTC ACG CCG TTA GCC

Question 18

12 The mRNA sequences of the three stop codons are shown:
UAA UAG UGA

which mutation in the template (transcribed) strand of DNA sequence that codes for a polypeptide would cause translation to stop prematurely?

Answer 18

ACC changed to ATT

Question 19

When a gene for protease is activated, which nucleic acid will be formed?

Answer 19

mRNA

Question 20

Put the process of translation in order 4

Answer 20

mRNA binds to the ribosome,

tRNA enters the ribosome carrying a specific amino acid,

Hydrogen bonds form between the anticodon and the codon

A peptide bond forms between adjacent amino acids

Question 21

During transcription, how many hydrogen bonds are formed when adjacent mRNA codons of AAU and CUG bind to complimentary tRNA anticodons? (do the maths)

Answer 21

Adenine and Uracil have 2 hydrogen bonds

Total no of adenine & uracil: 4

4x2=8

Guanine & cytosine have 3 hydrogen bonds

total no. of cytosine and guanine: 2

2x3=6

8+6=14

so 14

Question 22

how many hydrogen bonds does guanine have with cytosine?

Answer 22

three hydrogen bonds

Question 23

How many nucleotides in an amino acid?

Answer 23

three

Question 24

Do codons count as amino acids?

Answer 24

No

Question 25

Which events occur twice during transcription before the mRNA molecule leaves the nucleus?

Answer 25

Bonds break between complementary bases

bonds form between complementary bases

Question 26

A length of mRNA is 747 nucleotides long, including stop & start codons, how many amino acids will be produced in the polypeptide?

Answer 26

247

Question 27

How many genes are needed to code for a single haemoglobin molecule?

Answer 27

2

Question 28

What is the correct tRNA anticodon coding for the amino acid GGT (proline)?

Answer 28

GGU

(it’s not complementary bc it’s a tRNA copy of that strand, so the same but U)

Question 29

An antibiotic enters cells through a membrane channel protein, P.

some bacterial cells have shown resistance to this antibiotic by acquiring a mutation which alters P. This mutation prevents the entry of the antibiotic into the cell

which conclusions can be drawn about how resistance to this antibiotic developed i these bacteria?

Answer 29

The mutation resulted in the production of P with an altered tertiary structure

Question 30

Which bases are purines?

Answer 30

Guanine and adenine