Answer :There was enough oxygen in the atmosphere to support a major burst of life on Earth
Explanation:
The Great Oxygen Event marks the time, approximately 2.5 billion years ago, when there was enough oxygen in the atmosphere to support a major burst of life on Earth
For the first half of the Earht's history, there was no oxygen in the atmosphere. It was inhabited only by single-celled organisms.Of those simple life forms, the cyanobacteria may have. evolved a way to take energy from sunlight, and used it to make sugars out of water and carbon dioxide. They used the same chemical process we know as photosynthesis. This released vast quantities of oxygen into the atmosphere and triggered the evolution of complex life.
Specialization is what each cells personal function is, and differentiation is how one cell is different from another in any way
Answer: The correct answer is B) city hall:control center.
As per the question, model of cell looks like a city where different buildings correspond to different organelles ( membrane bound subcellular compartments like nucleus, golgi complex, vacuole, endoplasmic reticulum).
Nucleus is a specialized membrane bound compartment that possesses the genetic material ( DNA) of the Eukaryotes ( like plants and animals).
Nucleus controls all the essential activities of the cell by regulating the expression of gene ( segment of DNA corresponding to a particular protein).
Therefore, in the model of cell, city hall;control center represents the nucleus of the cell.
Quartz can produce energy. It is used to power watchs and many other items too
Answer:
Carnivorous predators.
Explanation:
Cambrian evolution took place about 541 million years ago. Sudden increase in Oxygen in the Ocean helped the complex organisms and predators to emerge. To survive among those predators, every species tried to develop complex body parts like shells, spines etc. Take for example Trilobites. They had flattened, segmented and plated bodies with spines to help them survive among the increasing number of predators in the sea.
