Question

q4. draw the structure of dna. how does a mutation cause a change in the protein made by cell. ku /3 + 3

Explanation:

DNA has a double - helix structure. It consists of two strands made of nucleotides. Each nucleotide has a sugar (deoxyribose), a phosphate group, and a nitrogenous base (adenine (A), thymine (T), guanine (G), or cytosine (C)). A pairs with T, and G pairs with C.

A mutation is a change in the DNA sequence. DNA provides the code for making proteins. The code is read in triplets (codons). If a mutation occurs, it can change the codon. For example, if a base substitution changes a codon, it may code for a different amino acid. Amino acids are the building blocks of proteins. Different amino acids can change the protein's structure and function.

Answer:

DNA is a double - helix. It has two strands of nucleotides (sugar - phosphate backbone with bases A - T, G - C). A mutation changes the DNA sequence. Since DNA codes for proteins (codons in DNA → amino acids in proteins), a changed codon (due to mutation) can lead to a different amino acid, thus altering the protein's structure and function.