Ch.17 MC Prep Flashcards
which statement is true about the genetic code?
there can be more than one codon for a particular amino acid
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?
1200
the relationship between a gene and a messenger RNA is as follows
mRNAs are made from genes
what structural configuration is antiparallel?
C5 to C3 ribose orientations run in opposite directions on the complementary stands
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
DNA; double-stranded
where in cell cycle is DNA replication occuring?
S-phase
limited gene-flow?
birds rarely move between the mainland and islands
sexual selection outcome acting on mules and horses?
the evolution of effective pre-zygotic isolating mechanisms
base pairing arrangement in DNA?
adenine & thymine guanine & cytosine
enzyme responsible for untwisting DNA?
helicase
which component is not directly involved in translation?
DNA
alternative splicing has been hypothesized to lead to what?
more than one mRNA from the same gene locus
three post-transcription modifications in mRNA in eukaryotes
- 5’ capping
- 3’ poly-A tail
- splicing
comparing closely related species, ______ well conserved but sequences of ________ are much less conserved
exons; introns
where in cell cycle do transcription and translation occur?
G1
relationship between mRNA and genes
mRNAs are made from genes
ribosomes are made of which macromolecule?
proteins and nucelic acids
_______ serves as evidence that life may have evolved before the central dogma
catalytic RNA
Each eukaryotic mRNA, even after post-transcriptional modification, includes 5’ and 3’ UTRs. Which are these?
untranslated regions at either end of the coding sequence
genetic code said to be triplet meaning…?
are three bases in mRNA that code for an amino acid
_______ are active in targeting mRNA molecules for degradation?
miRNA
In the structural organization of many eukaryotic genes, individual exons may be related to which of the following?
the various domains of the polypeptide product
______ protects the pre-mRNA molecule
3’ poly-A tail
the TATA sequence is found only several nucleotides away from the start of transcription, this relates to….?
the number of hydrogen bonds between A and T in DNA`
what is the initiator triplet in both prokaryotes and eukaryotes? amino acid?
AUG; methionine
events of protein synthesis in order?
(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
From the following list, which is the first event in translation in eukaryotes?
the small subunit of the ribosome recognizes and attaches to the 5’ cap of mRNA
mutations that are ________ are considered to be fixed.
not repaired
transversion mutation?
(two-ring) purine switched for (one-ring) pyrimidine
