Unit 1.3 DNA and the Genome

Question 1

True or false all of the genes in our cells are expressed?

Answer 1

False, in fact only a fraction of the genes in our cells are expressed

Question 2

What are the types of RNA involved in transcription and translation?

Answer 2

-mRNA
-tRNA
-rRNA

Question 3

What is RNA?

Answer 3

RNA is a single stranded molecule made up of nucleotides consisting of Ribose, a phosphate group , and one of four bases, cytosine, guanine, adenine, and uracil (instead of Thymine)

Question 4

What are some differences between RNA and DNA?

Answer 4

-DNA is double stranded where RNA is single stranded
-Nucleotides in DNA are made up of the sugar deoxyribose, where RNA are made up of the sugar Ribose
-In DNA molecules adenine pairs with thymine in RNA adenine will pair with Uracil.

Question 5

What is the role of mRNA in gene expression?

Answer 5

mRNA is transcribed in the nucleus and then leaves the nucleus and is translated into amino acids in the ribosome

Question 6

What is a triplet of mRNA bases called?

Answer 6

CODON

Question 7

What is the role of tRNA in gene expression?

Answer 7

tRNA has an anticodon at one and and an attachment site at the other end that carries a specific amino acid to the ribosome where the anticodon will temporarily bind to the codon of the mature mRNA transcript and this codes for the order in which the amino acids will be translated and the shape and therefore function of the protein produced.

Question 8

What is the role of RNA polymerase in the transcription of DNA?

Answer 8

RNA polymerase moves along the DNA unwinding the double helix and breaking the hydrogen bonds between bases and then will add an RNA nucleotides to produce a primary transcript of mRNA from the complementary base pairing of RNA nucleotides across the template strand.

Question 9

What does RNA splicing do?

Answer 9

Forms the mature mRNA transcript

Question 10

What are introns?

Answer 10

Non-coding regions of the primary mRNA transcript and are removed

Question 11

What are exons?

Answer 11

Coding regions of the mRNA transcript that are retained and joined together to form the mature mRNA transcript
(ex like expressed DNA)

Question 12

What happens to the order in which exons are arranged after RNA splicing?

Answer 12

The order of Exons remains unchanged.

Question 13

Where does the translation process begin and end?

Answer 13

The translation process begins at a start codon and ends at a stop codon.

Question 14

What type of bonding joins amino acids together?

Answer 14

peptide bonds

Question 15

What type of bonds hold the structure of the protein together?

Answer 15

hydrogen bonds

Question 16

What is the name of the process by which different proteins can be produced by the same gene?

Answer 16

alternative RNA splicing

Question 17

what is alternative RNA splicing

Answer 17

the process by which multiple proteins can be expressed by the same gene

Question 18

Why can different proteins be produced from the same mRNA transcript?

Answer 18

because the process of alternative RNA splicing allows different mature transcripts to be produced from the same primary transcript depending on which exons are retained.

Question 19

What determines an organism’s phenotype?

Answer 19

The proteins produced by that organism as a result of gene expression.