How do scientists calculate the age of the earth? what if the age of the earth?

Ablastocyst is a group of cells that forms after a human egg is fertilized. the blastocyst consists of two types of cells. some of these cells will become the placenta. what do the other cells develop into?

Types of scientific inquiry that biologist engage in that cannot be completely controlled

How does the diagram explain ocean currents? earth tilt 23.5 degreesquestion 1 options: earth's tilt causes uneven heating of earth which causes currents.earth's tilt causes the ocean to move because of gravity.earth's tilt and its rotation cause currents.earth's tilt causes uneven distribution of salt which causes currents.