Question

hemoglobin is a protein present in red blood cells. in the genetic disease sickle cell anemia, there is a mutation in the hemoglobin protein. the mutation results in hemoglobin proteins that clump together abnormally in cells. this is that are sickled (crescent - shaped) rather than round. sickled cells are fragile and can cause damage to tissue through how do changes in the hbb gene affect body function? place phrases into the table in the correct order to explain how gene affect body tissue function.

step	sequence of how changes in hbb gene affect body tissue function
2
3
4

mutation occurs in dna sequence
abnormally shaped amino acids form
mutation occurs during protein folding
abnormal sequence of amino acids forms
proteins that form are abnormal in shape and behavior
cell shape is irregular, resulting in abnormal cell and tissue function

Explanation:

Step1: Identify the starting point

The process begins with a mutation in the DNA sequence of the HBB gene. So the first step is "Mutation occurs in DNA sequence".

Step2: Effect on amino acid sequence

A DNA mutation leads to an abnormal sequence of amino acids being formed during protein synthesis. So the second step is "Abnormal sequence of amino acids forms".

Step3: Effect on protein folding and shape

The abnormal amino acid sequence causes issues during protein folding, leading to abnormally shaped amino acids (or the protein) and then abnormal protein shape and behavior. Wait, actually, the correct order after abnormal amino acid sequence is that the protein folding is affected, but among the given options, after abnormal amino acid sequence, the next is that the proteins formed are abnormal in shape and behavior? Wait, no, let's correct. The correct sequence is: 1. Mutation occurs in DNA sequence (of HBB gene). 2. Abnormal sequence of amino acids forms (because DNA codes for amino acid sequence). 3. Mutation occurs during protein folding? No, the mutation is in DNA, then amino acid sequence is abnormal, then during protein folding, the abnormal amino acid sequence leads to abnormal protein structure. But among the given phrases, "Mutation occurs during protein folding" is incorrect. Wait, the correct phrases and order:

1. Mutation occurs in DNA sequence (of HBB gene) - this is the initial genetic change.

1. Abnormal sequence of amino acids forms - because the DNA mutation changes the codons, so the amino acid sequence is abnormal.

1. Proteins that form are abnormal in shape and behavior - because the abnormal amino acid sequence leads to improper protein folding, resulting in abnormal protein structure and function (like hemoglobin clumping).

1. Cell shape is irregular, resulting in abnormal cell and tissue function - because the abnormal hemoglobin (protein) causes red blood cells to sickle, which then affects tissue function.

Wait, but there are other phrases: "Abnormally shaped amino acids form" and "Mutation occurs during protein folding" - these are incorrect. Let's re - evaluate the correct biological sequence:

• Genetic mutation: Mutation occurs in DNA sequence (of HBB gene).

• Transcription and translation: Abnormal sequence of amino acids forms (since DNA codes for mRNA, which codes for amino acids).

• Protein folding: The abnormal amino acid sequence leads to abnormal protein folding, resulting in proteins that are abnormal in shape and behavior (like hemoglobin S in sickle cell).

• Cellular effect: The abnormal hemoglobin causes red blood cells to become sickled (irregular cell shape), which then leads to abnormal cell and tissue function.

So the correct order for the four steps is:

Step 1: Mutation occurs in DNA sequence

Step 2: Abnormal sequence of amino acids forms

Step 3: Proteins that form are abnormal in shape and behavior

Step 4: Cell shape is irregular, resulting in abnormal cell and tissue function

Answer:

Step	Sequence of How Changes in HBB Gene Affect Body Tissue Function
2	Abnormal sequence of amino acids forms
3	Proteins that form are abnormal in shape and behavior
4	Cell shape is irregular, resulting in abnormal cell and tissue function