What event occured during paleozoic era? A. diversification of mammals

B. beginning of multicelled life

C. first appearance of most invertebrates

D. dominance of non avian dinosaurs​

C) first appearance of most invertebrates.

Explanation:

The Cambrian Explosion occurred 542 mya. The earliest complex animals arose in the sea at the beginning of the Cambrian Explosion. It would take another half a billion years for mammals to rise. Multicellular life dates back 1.2 bya, but more cpomplex life, such as animals, did not occur until the Cambrian Explosion. In the beginning of the Cambrian Explosion, many soft-bodied animals, such as jellyfish and sea anemones appeared.

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.

thats not even an aswer choice