B. New substances are formed. In a chemical reaction, the starting molecule must be changed or turn into another. For example: rusts that form in a tin can is a chemical reaction. The iron in the can combines with the oxygen in the atmosphere, creating rust (iron oxide), which is a different substance.
Answer:
Every human has a couple of genes that will be separated when they make gametes. A baby will get one gene from each parent (one sperm and one egg).
Sickle cell gene is inherited by an autosomal recessive pattern, which means you need both defect genes to get the disease. The person with 1 defect gene can survive and live like normal. This person called a carrier because they carry one defect gene.
Someone that carries one defect gene can come as a result if you cross normal or carrier genotype (AA/Aa) with a carrier(Aa), or with homozygote recessive that carries 2 defect genes (aa). The person will get one healthy gene from the first parent with normal genes, and one defect gene from the second parent.
I’d say B is the best choice
Hope this helps
-AaronWiseIsBae