How does the composition of the nucleus change during fission, fusion, and radioactive decay?

Imagine that you have produced several versions of lactase, each of which differs from normal lactase by a single amino acid. describe a test that could indirectly determine which of the versions significantly alters the three-dimensional shape of the lactase protein.

1) these are barrel shaped microtubules in most animal cells, that organize the spindles during cell division

Explain that newton first law,second law and third law of motion?