When we are born, we have about how many brain cells?

The correct answer will be- 100 billion brain cells or neurons

Explanation:

The development of brain starts after three weeks of conception in the womb and the brain cells called neurons starts developing in the brain.

The brain usually develops about 100 billion neurons at the time of birth with very few synapses about 2500 synapse per neuron. In the first few years, the number of neurons increases to trillions and the formation of synapses begins and reaches about 15000 synapses per neuron at the age of five.

Thus, 100 billion brain cells or neurons is the correct answer.

climate change and pollution

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs