Answer:
1) About 8.7 million.
2) They are being found everywhere.
Reproductive isolation must happen
Answer:
B
Explanation:
RNAi is a cellular mechanism for post-transcriptional gene silencing. After transcription of a gene into mRNA, small interfering RNA (siRNA) and microRNA (miRNA) can target the mRNA to form dsRNA. This mRNA then becomes a target of ribonucleases such as the Dicer that break it apart. These mRNA, therefore, do not reach the cytoplasm for translation by ribosomes. This mechanism is hence harnessed and manipulated by scientists to study genes by silencing them.
Answer:
Energy is required to disrupt a substrate’s stable electron configuration.
Explanation:
Activation energy is the energy required to initiate the chemical reaction. Activation energy is always kinetic energy. Activation energy is used to break the existing bonds of the substrate to destabilize it.
Breaking of existing bonds of the substrates creates a transition state which in turn has higher free energy than both reactants and products. Once the transition state is formed, the reaction proceeds towards the formation of the product.
Enzymes serve to lower down the activation energy for the reaction and thereby allow the reaction to occurs at a higher rate even at a normal temperature.