Ch.17 MC Prep

Question 1

which statement is true about the genetic code?

Answer 1

there can be more than one codon for a particular amino acid

Question 2

a particular protein is 400 amino acids long. How many nucleotide base pairs in the template strand of DNA are required to code got this protein?

Answer 2

1200

Question 3

the relationship between a gene and a messenger RNA is as follows

Answer 3

mRNAs are made from genes

Question 4

what structural configuration is antiparallel?

Answer 4

C5 to C3 ribose orientations run in opposite directions on the complementary stands

Question 5

table: source A G T C U (1) 20 30 0 10 40 (2) 20 30 20 30 0 (3) 20 20 30 30 0

Answer 5

DNA; double-stranded

Question 7

where in cell cycle is DNA replication occuring?

Answer 7

S-phase

Question 8

limited gene-flow?

Answer 8

birds rarely move between the mainland and islands

Question 9

sexual selection outcome acting on mules and horses?

Answer 9

the evolution of effective pre-zygotic isolating mechanisms

Question 10

base pairing arrangement in DNA?

Answer 10

adenine & thymine guanine & cytosine

Question 11

enzyme responsible for untwisting DNA?

Answer 11

helicase

Question 12

which component is not directly involved in translation?

Answer 12

DNA

Question 13

alternative splicing has been hypothesized to lead to what?

Answer 13

more than one mRNA from the same gene locus

Question 14

three post-transcription modifications in mRNA in eukaryotes

Answer 14

• 5’ capping
• 3’ poly-A tail
• splicing

Question 15

comparing closely related species, ______ well conserved but sequences of ________ are much less conserved

Answer 15

exons; introns

Question 16

where in cell cycle do transcription and translation occur?

Answer 16

G1

Question 17

relationship between mRNA and genes

Answer 17

mRNAs are made from genes

Question 18

ribosomes are made of which macromolecule?

Answer 18

proteins and nucelic acids

Question 19

_______ serves as evidence that life may have evolved before the central dogma

Answer 19

catalytic RNA

Question 20

Each eukaryotic mRNA, even after post-transcriptional modification, includes 5’ and 3’ UTRs. Which are these?

Answer 20

untranslated regions at either end of the coding sequence

Question 21

genetic code said to be triplet meaning…?

Answer 21

are three bases in mRNA that code for an amino acid

Question 22

_______ are active in targeting mRNA molecules for degradation?

Answer 22

miRNA

Question 23

In the structural organization of many eukaryotic genes, individual exons may be related to which of the following?

Answer 23

the various domains of the polypeptide product

Question 24

______ protects the pre-mRNA molecule

Answer 24

3’ poly-A tail

Question 25

the TATA sequence is found only several nucleotides away from the start of transcription, this relates to….?

Answer 25

the number of hydrogen bonds between A and T in DNA`

Question 26

what is the initiator triplet in both prokaryotes and eukaryotes? amino acid?

Answer 26

AUG; methionine

Question 27

events of protein synthesis in order?

Answer 27

(42135)
- small ribosomal subunit binds to mRNA
- aminoacyl-tRNA binds to A-site
- peptide bonds from between new amino acids and a polypeptide chain
- empty tRNA leaves P-site and move tot he E site and leaves the ribosome
- peptidyl tRNA translocates to the P site from A site

Question 28

From the following list, which is the first event in translation in eukaryotes?

Answer 28

the small subunit of the ribosome recognizes and attaches to the 5’ cap of mRNA

Question 29

mutations that are ________ are considered to be fixed.

Answer 29

not repaired

Question 30

transversion mutation?

Answer 30

(two-ring) purine switched for (one-ring) pyrimidine