Sr-90 has a half-life of 30 years. If our sample of Sr-90 now has a mass of 1500 grams, what was the mass of our Strontium-90 90 years ago.

How are gene and protein sequences used to classify organisms?

The unique structure of the neuron is dedicated to the efficient and rapid transmission of neural signals. the relationship between neurons, the spinal cord, and the brain constitutes an elaborate communication system throughout the human body. all but one of the functions listed below are a result of this interaction.

Discuss cell surface transport in the structure of constituents