Biology ! help- i dont get these questions?

Question

i got these three wrong and i cant figure out the right answers...

1.) why is it eaiser to define protists by what they are not, rather than what they are?

2.) Describe the proposed relationship between prokaryotes and the organelles in eukaryotes.

here is the third:
3.) Use your knowledge of the Greek orgins of the word protist to determine a possible meaning for the term protogalaxy.

Answer 1

1. theres many varieties of protists
2. serial endosymbiosis, prokaryotes moved into eukaryote cells

Answer 2

1. Don't know that one, too esoteric.

2. Many organelles within eukaryotic cells are thought to be prokaryotic cells in a symbiotic relationship with the cell. The mitochondria are the best known example. There are free living bacteria which are thought to be the relatives of mitochondria. It is thought that this symbiosis is the basis of the development of the eukaryotes, that is, a prokaryotic cell once ingested another cell, but instead of being digested it, it began producing energy useful to the cell, and so it has remained. (That is an extremely simple version, but you may get the gist of it). Mitochondria have there own DNA, and replicate independently of the rest of the cell.

Answer 3

asexual. I'm not going to give you the answer but I'm going to help you. Think about bacteria and how successful they've been in this planet. They reproduce asexually through binary fission. asexual reproduction: -it's faster than sexual reproduction -it requires less energy than sexual reproduction -ability to reproduce without a partner in situations where the population density is low