Answer:
C) It involves interactions between biotic and
abiotic factors.
Explanation:
Ecosystems need energy imput, need both consumers and producers, and can exist on land, lakes, rivers and oceans.
Answer: B. Melting temperatures of primer should be between 55-80 degree Celsius.
Explanation:
Bacause the melting temperature controls the binding of the primers to your template DNA. At melting temperature 50% of the primer molecules are bound to their corresponding target sequence. If the difference in melting temperature between the two primers is too high, it might be difficult to find experimental conditions where both primers can bind to their target.
The answer is fusion of gametes via fertilization.