Lesson 8
- To get back to haploid cells, the protist couldn't just divide once, as in mitosis. Why not? How many times did the protist have to divide, and how many daughter cells did this eventually produce?
- The protist attempted cannibalism, but didn't digest the DNA of its victim. - The protist, now diploid, replicated its DNA and thus became quatroploid. - The protist chopped up the chromosomes and reassembled them incorrectly. - The protist underwent two rounds of genome separation and cytokinesis. 4 daughter cells
- If all members of a species have the same genomes, then why aren't they all clones?
Alleles, the genes come in different versions
- When the cannibalistic protist attempted to consume another of its own species, what happened to the victim's DNA, and why?
Because the victim's chromosomes were so similar to its own, the cell thought that the victim's chromosomes WERE copies of its OWN chromosomes. Cells don't digest their own chromosomes
- Explain two ways that bacteria mix genomes. Do these processes mix genomes within a new generation, as sexual reproduction does? If not, what is happening instead?
In CONJUGATION, one bacterium shares a copy of some of its genes with another bacterium. TRANSFORMATION,
- Why have failed cannibals and their descendants become more common on Earth than cells that only produce clones of themselves?
In other words, there were ALLELES in the original cannibal protist that enabled it to go through the whole failed cannibalism attempt in the first place. And, these alleles were passed on to at least some of the cannibal's daughter cells.
- Why did the cannibalistic protist replicate its DNA, and the DNA of its victim?
It's as if those extra chromosomes from the victim jumpstarted the cell to start mitosis at the very beginning. What happens at the beginning of mitosis? DNA replication!
- According to this hypothesis, how many eukaryotes alive today are descended from protists that failed cannibalism?
Many eukaryotes alive today are descendants of protists that failed cannibalism
- When, and why, are the progeny of failed cannibalism attempts more likely to survive than those produced by mitosis?
Populations that contain genetic variability are more likely to survive in changing environments. In things like diseases and temperatures
- Approximately how many protists, fungi, plants, and animals reproduce sexually?
all
- How did the protist's chromosomes become a jumbled mix of its own genes, plus the genes of its victim?
copied every single chromosome. After finishing, it had FOUR copies of every chromosome
- Do bacteria reproduce sexually?
no
- What is the process of failed cannibalism actually called, in eukaryotes that practice it today?
sexual reproduction.
