D. 1,200
This is because if it takes 1 and a half hours **1.5** to travel through city a and city b , and the plane goes 800km per hour and 400km is half of that it then the answer has to be d.
Answer: B) The experimental group tests to see if the presence of Balanus in some manner prevents Chthamalus from growing.
Explanation:
The most logical third step in Connell's experimental procedure, permitting him to either accept or reject his hypothesis of competitive exclusion is the experimental group tests to see if the presence of Balanus in some manner prevents Chthamalus from growing.
Balanus is a species of crustacean, as know as sea acorns, whereas Chthamalus is a species of barnacles that can easily be found in the northern hemisphere's coasts.
Explanation:
Psi packaging Element is a cis-acting RNA element identified in the genomes of the retroviruses Human immunodeficiency virus (HIV) and Simian immunodeficiency virus (SIV) It is involved in regulating encapsidation of the retroviral RNA, an essential step in replication.