Chapter 14 Learning Curve

Front 1

introns are usually indicated by

Back 1

loops

Front 2

there is always one more exon than an intron

Back 2

true

Front 3

which type of RNA molecule is derived from a long single stranded RNA transcripts and known to suppress the expresssion and movement of transposons in animal germ cells?

Back 3

piRNA

they bind to Piwi proteins and degrade mRNA transcribed from transposons

Front 4

which mechanism is used by cells to regulate gene expression and defend against certain viruses and by researchers to block expression of specific genes?

Back 4

RNA interference

Front 5

process by which expression of a specific gene is blocked in the presence of a double-stranded RNA molecule

Back 5

RNA interference

Front 6

Anticodon of a tRNA molecule

Back 6

It serves as the attachment site for amino acids. It is CCA.

Front 7

which mechanism produces from a single gene, multiple mRNAs of different lengths, encoding different polypeptides?

Back 7

alternative splicing and RNA editing

Front 8

which mechanism produces from more than one gene, multiple mRNAs of different lengths, encoding different polypeptides?

Back 8

trans-splicing

Front 9

what is present on a bacterial gene but not a eukaryotic gene?

Back 9

shine-dalgarno sequence in the 5' UTR

Front 10

what is the function of the shine-dalgarno sequence?

Back 10

serves as a ribosome binding site during translation

Front 11

what critical observation led to disproving rRNA as the intermediary molecule?

Back 11

the ribosomes isolated after switching the phage-infected bacterial cells to grow in a medium containing lighter radioisotope, only contained the original heavy isoptopes. (15N and 13C).

The bacterial ribosomes required for phage propagation were not newly produced upon the phage infection coupled with media switch

Front 12

which of the following types of genes would typically only contain nucleotide sequences designed for amino acid sequence of a protein?

Back 12

neither bacterial nor eukaryotic genes.

this notion does not account for sequences that are transcribed but not part of the coding region in both eukaryotic and prokaryotic genes

Front 13

which RNA molecules help to cleave and modify eukaryotic rRNAs?

Back 13

small nucleolar RNAS (snoRNAs)

Front 14

which mechanism allows rare bases to be incorporated into tRNA molecules?

Back 14

enzyme-mediated chemical modifications of normal RNA bases

Front 15

function of tRNA modifying enzymes

Back 15

they convert normal RNA bases in tRNA into rare bases

Front 16

a particular mutation occurs, which results in changing of the branchpoint A within an intron to a U. What is the most likely effect of this mutation?

Back 16

production of a longer than normal mRNA and an abnormal protein product

Front 17

further description--->

Back 17

in the absence of a functional branchpoint, the intron will not be removed, and the coding sequence will be disrupted

Front 18

a geneticist identifies an mRNA molecule in which the 5' end is derived from a gene on chromosome 3 and the 3' end is derived from a gene on chromosome 6. Which mechanism can explain this?

Back 18

trans-splicing

Front 19

transcription and translation are separated temporarily as well as spatially in_______cells

Back 19

eukaryotic cells

Front 20

which type of molecule can accomplish RNA interference by inhibiting transcription and generally is derived from sequences within the gene that it regulates?

Back 20

siRNA

these molecules are derived from their target genes and can inhibit transcription of target genes

Front 21

this mechanism puts together exons that are derived from different genes

Back 21

trans-splicing

Front 22

where are rRNAs modified?

Back 22

modified by snoRNAs in the nucleolus where ribosomal subunits are assembled

Front 23

fd

Back 23

dsf