Test 2, Deck 2

Question 1

Which E. coli strains will produce B-galactosidase with no glucose and normal lac Z and lac Y genes.

Answer 1

Will be produced with lactose. (only expressed if lactose is present to change to shape of repressor and for it to fall off. if glucose is there, lactose is present = translation still repressed.)

Question 2

The lac I gene codes for which protein?

Answer 2

Repressor protein

Question 3

Which lac operon gene(s) is/are required to allow lactose to enter E. coli?

Answer 3

Lac y ; codes for permease, transport protein that carries lactose to cell

Question 4

Which lac operon gene(s) is/are codes for B-galactosidase?

Answer 4

Lac Z: enzyme breaks lactose into glucose and glactose

Question 5

Which amino acid is coded by the DNA codon GGG?

Answer 5

Pro: mRNa codon is CCC

Question 6

Choose the amino acid seq. that would be translated from the mRNA : 5’ AAUGAAAGUGAAGUAA 3’

Answer 6

Met - Lys - Val - Lys - Stop

Question 7

Choose the sequence of mRNA that would be transcribed from the DNA 5’ TAC GCA CAT 3’

Answer 7

3’ AUG CGU GUA 5’

Question 8

Which strand will be used as the template for transcription?
5’ Promoter
3’ Promoter

Answer 8

Bottom strand

Question 9

RNA is stabilized after transcription in cells of…

Answer 9

Eukaryotes (by 5’ cap and poly-A-tail)

Question 10

RNA polymerase ends transcription at a termination sequence in cells of…

Answer 10

Prokaryotes and Eukaryotes (but they need proteins as well: transcription factors)

Question 11

Describe one structure feature of tRNA not found in mRNA or pre-mRNA

Answer 11

Clover-shape, double-stranded areas, with anti-codon, with amino acid attached…

Question 12

Describe one structure feature of mRNA not found in tRNA or pre-mRNA

Answer 12

Poly-A tail or 5’ cap

Question 13

Match the transcription required elements with the translation required elements :
Terminator - Promoter - RNA nucleotide - RNA polymerase

Answer 13

Stop codon (UGA, UAA or UAG) - AUG - amino acids - Ribosomes

Question 14

Describe one structure feature of pre-mRNA not found in tRNA or mRNA

Answer 14

Presence of introns in structure (pre-mRNA os before processing, before 5’ cap, poly-a tail, removing introns…)

Question 15

What structural feature do pre-mRNA tRNA and mRNA have in common?

Answer 15

Presence of nitrogenous bases, presence of ribose sugar, single stranded, They all have a 3’ end and a 5’ and , they are single stranded

Question 16

What functions do pre-mRNA tRNA and mRNA have in common?

Answer 16

Their main function is the same : protein synthesis, they all contribute to the making of polypeptide chains.

Question 17

Write the mRNA and the amino acid linked to this DNA :
3’ AGTGGATACGTACGACATG promoter 5’
5’ TCACCTATGCATGCTGTAC promoter 3’

Answer 17

Bottom strand:
mRNA 3’ AGUGGAUACGUACGACAUG 5’
Met - His - Arg - Stop

Question 18

Label the components of nucleotides

Answer 18

Phosphate nitrogenous base
5’ deoxyribose (one OH)
2’

Question 19

Thymine makes 15% of the bases in DNA molecule, what is the percentage of the bases of cytosine?

Answer 19

35%

Question 20

Mating between cats produces: 1/4 calico female, 1/4 orange female, 1/4 orange male, 1/4 black male. What is the genotype of the male parent?

Answer 20

Male : X(orange)Y

Question 21

Hypophosphatemia is caused by an X-linked dominant gene. Man with hypo. mates with normal woman. What proportion of their children are expected to have hypo.?

Answer 21

1/2