Non-boiled seeds show no starch reaction due to active enzyme digestion

Steps:

• Non-boiled bean seeds contain living cells with active enzymes.
• Amylase in non-boiled seeds hydrolyzes starch into sugars.
• Iodine test on non-boiled seeds yields no blue-black color as starch is absent.
• Boiled seeds denature amylase, preserving starch for positive iodine reaction.

Why D is correct:

• D explains active amylase prevents starch accumulation, per enzyme catalysis definition where non-denatured proteins function in vivo.

Why the others are wrong:

• A: Iodine absorption unrelated to lack of color change; test detects starch presence.
• B: Acid content does not affect iodine-starch reaction specificity.
• C: Amylase presence alone insufficient without noting its activity in non-boiled state.

Not enough information on exact results or full choice D text.

Final answer: D