- Cephalopods show a much higher degree of structural and behavioral complexity than other groups of molluscs
What factors triggered the evolution of these changes? A rich fossil record shows that once they were very common
and even dominant in some environments. Now there are only about 650 living species of cephalopods, far fewer
than gastropods Were cephalopods successful? What do you think happened along the way?

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.

essentially, one bacterial cell splits into two daugurer cells. bacterial offspring don't need or get care from their parents because they are in a sense their own parents. that said, some bacteria can and do depend on other bacteria especially in harsh environments such as bacterial microfilms in hot water tanks.