Answer
code
Work Step by Step
# 8.12 (Bioinformatics: find genes) Biologists use a sequence of letters A, C, T, and G to
# model a genome. A gene is a substring of a genome that starts after a triplet ATG
# and ends before a triplet TAG, TAA, or TGA. Furthermore, the length of a gene
# string is a multiple of 3 and the gene does not contain any of the triplets ATG, TAG,
# TAA, and TGA. Write a program that prompts the user to enter a genome and displays
# all genes in the genome. If no gene is found in the input sequence, the program
# displays no gene is found.
def findGen(genome):
found = False
for i in range(len(genome)):
startInd = str(genome).find("ATG")
if startInd == -1:
break
endInd1, endInd2, endInd3 = \
str(genome).find("TAG"), str(genome).find("TAA"), str(genome).find("TGA")
if endInd1 == -1:
endInd1 = len(genome) * 2
if endInd2 == -1:
endInd2 = len(genome) * 2
if endInd3 == -1:
endInd3 = len(genome) * 2
endInd = min(endInd1, endInd2, endInd3)
gen = str(genome)[startInd + 3:endInd]
if len(gen) % 3 == 0:
print(gen)
found = True
genome = genome[endInd + 3:len(genome)]
if not found:
print("No genes found")
def main():
g = input("Enter a genome string: ")
findGen(g)
main()
