Exercise 3: Analyzing DNA Data from the Human Genome Project Problem: You are provided with a CSV file named 'dna_data.csv'. Each row contains a DNA sequence identifier and a DNA string (e.g., 'seq1,ATCGTACG...'). Write a Python program to: 1. Read the file and print the first 5 rows. 2. Count the number of sequences that contain the substring 'ATG' (start codon). 3. Write the identifiers of these sequences to a new file named 'start_codon_sequences.txt