Topic 3

Question 1

How much genes are actually expressed in a cell ?

Answer 1

Only a fraction of the genes in a cell are expressed

Question 2

What are gene expression influenced by ?

Answer 2

Gene expression is influenced by intra and extra cellular environmental factors .

Question 3

What is gene expression controlled by ?

Answer 3

Gene expression is controlled by both transcription and translation

Question 4

What the structure of rna

Answer 4

Rna is single stranded , contains uracil instead of thymine and ribose instead of deoxyribose sugar

Question 5

Where does the messenger rna (mRNA ) carry a copy of Dna from and to ?

Answer 5

Messenger rna carries a copy of the dna code from the nucleus to the ribosome

Question 6

What forms the ribosome

Answer 6

Ribosomal RNA (rRNA ) and proteins form the ribosome

Question 7

Each transfer rna (tRNA ) carries ?

Answer 7

Each transfer RNA (tRNA) carries a specific amino acid

Question 8

RNA transcripts take place where ?

Answer 8

RNA transcripts take place in the nucleus

Question 9

RNA transcripts include the role of ?

Answer 9

The role of RNA polymerase and complementary base paring

Question 10

What are the introns in the primary transcript and what happens to them in RNA splicing ?

Answer 10

The introns of the primary RNA transcript are non coding and are removed in the RNA splicing

Question 11

What are exons and what happens to them during RNA splicing

Answer 11

The exons are coding regions and are joined together to form a mature transcript

Question 12

What’s the process called with the removal of introns and joining of exons ?

Answer 12

RNA splicing

Question 13

Where does tRNA take place ?

Answer 13

Ribosome

Question 14

What does the tRNA fold because of ?

Answer 14

tRNA folds due to base paring

Question 15

What does the tRNA fold ?

Answer 15

tRNA folds to from a triplet anticodon site and an attachment site for a specific amino acid

Question 16

What do the triplet codons and anticodons do on the mRNA ?

Answer 16

Triplet codons and anticodons on the mRNA translate the genetic code into a sequence of amino acids

Question 17

What are start and stop codons ?

Answer 17

Start codons are the first codon and the stop codon is the last codon that stops further addition to the polypeptide chain

Question 18

What can be expresses from one gene as a result of alternative RNA splicing and post translational modification ?

Answer 18

Different proteins can be expressed from one gene as a result of alternative RNA splicing and post translational modification

Question 19

Different proteins can be expressed form one gene as a result of ?

Answer 19

Alternative RNA splicing and post translational modification

Question 20

Different mRNA molecules are produced from the same primary transcript depending on ?

Answer 20

Which RNA segments are treated as exons and introns

Question 21

What is post translation protein modification ?

Answer 21

Post translation protein structure modification by cutting and combing polypeptide chains or by adding phosphate or carbohydrate groups to the protein .

Question 22

Cutting and combining polypeptide chains or by adding phosphate or carbohydrate group to the protein is ?

Answer 22

Post translation protein structure modification

Question 23

What is the phenotype determined by ?

Answer 23

Phenotype is determined by the proteins produced as a result of gene expression