Which two statements describe disadvantages of selective breeding?​

This is giving me a headache i have asked others and they don’t know it either

The answer to this will be from your lab notes/procedure. it would be best to ask another student who participated in the lab as we do not know what was done, what enzyme or if the temperature is celsius or fahrenheit. if i were to guess though i'd say the rate stopped due to enzyme denturing at high temperature

Ithink its because more have died recently than in the past.