The picture shows a type of rock called a banded iron formation. the rock contains high levels of iron oxides minerals, which form only when iron at earth's surface combines with oxygen. approximately how old would earth's oldest banded iron formations be? 3 billion years old 4.6 billion years old 5 billion years old 65 million years old

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.

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what do the different brain waves do?

explanation:

brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other. brainwaves are detected using sensors placed on the scalp. brainwave speed is measured in hertz (cycles per second) and they are divided into bands delineating slow, moderate, and fast waves.