Answer:
The answer you are looking for is A.
The Precambrian era envelopes the major bulk of the history of the Earth, beginning from the creation of the planet approx 4.5 billion years ago and terminating with the origination of composite, multicelled forms of life approximately 4 billion years after.
The Precambrian refers to the earliest of the geologic ages that are signified by the distinct layers of sedimentary rock. The Earth was about more than six hundred million years old when life started. The planet had cooled down from its native molten state, creating a solid crust and oceans formed by water vapor in the atmosphere.
At about three billion years ago, the atmosphere of the Earth was virtually devoid of oxygen. At approximately 2.4 billion years ago, oxygen was discharged from the seas as a waste product of photosynthesis by cyanobacteria. The levels of the gas slowly raised, attaining about 1 percent around two billion years ago.
Approximately 800 million years ago, the levels of oxygen attained about 21 percent and started to breathe life into more composite species. The oxygen-rich ozone layer was also created, protecting the surface of the Earth from the harmful solar radiation.
Answer: Organism in this domain can be defined as living things that has an organized structure, and responds to stimuli, and has ability to reproduce, grow, and maintain a state of equilibrium. Organisms are of two types which are unicellular and multi cellular organisms.
Explanation: unicellular organisms are organisms that are made up of only one cell which carries out all the functions needed by the oragnism. Multicellular organisms are organisms that are made up of more than one cell. These organisms uses many different cells to function.
Unicellular organisms are often found in extreme environments such as hot springs, polar ice and frozen tundra.
Unicellular organisms have cell that contain a nucleus.
Answer:
Identify the general location of the zygomatic arch. cheek. The zygomatic arch is a bony bridge formed between the zygomatic and temporal bones. ... The temporal process of the zygomatic bone and the zygomatic process of the temporal bone fuse to form the zygomatic arch.
Explanation:
possible
answer
P<span>atients who cannot afford to purchase bone marrow will have to wait for voluntary donors.</span>
