If both parents have normal red blood cells then how can the child have sickle cell anemia PLS HELP ME

It's due to hereditary

Explanation:

Hereditary Is something that is passed on from family generations. It can pass on genes and disease's. From past family members in blood lines.

Example: My grandpa had cancer but my mom and dad did not but I still have his blood and when I'm 30 I get diagnosed with cancer and die 1 year later.

Hope this helps :)

weathering is the answer.