The Precambrian time refers to the time 4.5 billion to 542 millions year ago. This period is characterized by having reduced atmosphere and included reduced compounds. Scientists believed that atmosphere at that time was devoid of free oxygen and CO2 was present in excess. Before the complex life evolved on the Earth, the Precambrian Earth's ocean contained dissolved carbon dioxide.
Answer:
The answer is A.
Explanation:
It can be regulated with negative feedback loops.
Nonmetals take electrons from the metals they are attracted to in order to become stable.
Answer:
C
Explanation:
Without crossing over, each chromosome would be either maternal or paternal, greatly reducing the number of possible genetic combinations, which would greatly reduce the amount of genetic variation between related individuals and within a species.
A. The Answer to this question is Mutation.
