Question

second position
first position (5 end)
third position (3 end)
u
c
a
g
u
uuu
uuc
phe
uua
uug
leu
ucu
ucc
uca
ucg
ser
uau
uac
tyr
uaa
stop
uag
stop
ugu
ugc
cys
uga
stop
ugg
trp
u
c
a
g
c
cuu
cuc
cua
cug
leu
ccu
ccc
cca
ccg
pro
cau
cac
his
caa
cag
gln
cgu
cgc
cga
cgg
arg
u
c
a
g
a
auu
auc
aua
ile
aug
met start
acu
acc
aca
acg
thr
aau
aac
asn
aaa
aag
lys
agu
agc
ser
aga
agg
arg
u
c
a
g
g
guu
guc
gua
gug
val
gcu
gcc
gca
gcg
ala
gau
gac
asp
gaa
gag
glu
ggu
ggc
gga
ggg
gly
u
c
a
g
initiation
termination
which codons code for the amino acid arginine (arg)? select all that apply.
cgu
aga
ugc
cgc
agc

Explanation:

Step1: Analyze each codon

• For CGU: Check the codon table. In the table, when first position is C, second is G, third is U, the amino acid is Arg. So CGU codes for Arg.
• For AGA: First position A, second G, third A. From the table, this codes for Arg.
• For UGC: First U, second G, third C. The amino acid here is Cys, not Arg.
• For CGC: First C, second G, third C. This codes for Arg.
• For AGC: First A, second G, third C. This codes for Ser, not Arg.

Step2: Identify correct codons

From the analysis, CGU, AGA, and CGC code for arginine.

Answer:

A. CGU, B. AGA, D. CGC