Answer:
The correct answer is C. replication fork.
Explanation:
The period during which the presence of stromatolites decline is the Proterzoic period. Stromatolites are widely distributed sedimentary structures consisting of laminated carbonate or silicate rocks, produced over geologic time by the trapping, binding, or the precipitating of sediment by groups of microorganisms, primarily cyanobacteria.
Answer:
Biotic: Plants
Abotic: Rocks
Explanation:
A biotic factor is something in an ecosystem or environment that is living. Some examples that could be found in a park are grass, flowers, trees, squirrels, pigeons, fish or people.
An abiotic factor is the exact opposite of a biotic factor: something in an ecosystem or environment that is not alive. Some examples that may be found in a city park include a park bench, a trash can, rocks, a playground, a pool, basketball court, temperature, and humidity.
The brain is incorrect. Its the nucleus (the brain is an organ not a organelle)
hope that helps :)