Codons Found in Messenger RNA Second Base
First Base U C A G Third Base
U Phe
Phe
Leu
Leu Ser
Ser
Ser
Ser Tyr
Tyr
Stop
Stop Cys
Cys
Stop
Trp U
C
A
G
C Leu
Leu
Leu
Leu Pro
Pro
Pro
Pro His
His
Gln
Gln Arg
Arg
Arg
Arg U
C
A
G
A Ile
Ile
Ile
Met Thr
Thr
Thr
Thr Asn
Asn
Lys
Lys Ser
Ser
Arg
Arg U
C
A
G
G Val
Val
Val
Val Ala
Ala
Ala
Ala Asp
Asp
Glu
Glu Gly
Gly
Gly
Gly U
C
A
G

This table shows the codons found in messenger RNA. Using this information, what sequence of nucleotides in the template strand of DNA could code for the polypeptide sequence Val-Asp-Ser?
GUU-GAU-AGC
CAA-CTA-TCG
GTT-GAT-AGC
CAA-CUA-UCG

Compare and contrast the relative importance of the sporophyte vs gametophyte generation between nonvascular plants (bryophytes), seedless vascular plants and seed plants, and explain the ecological significance of a larger sporophyte generation

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?

Explain how scientists use geologic time to determine the age of landforms.