Question

extension questions

1. colchicine is a poison that acts to inhibit the development of spindle fibers. describe the effects on mitosis in a cell that has been treated with colchicine.
2. binary fission is cell division in prokaryotic organisms (bacteria), which have no nucleus. in addition, prokaryotic cells typically have only one circular chromosome. together with your group, predict how binary fission in prokaryotic cells might be different than mitosis in eukaryotic organisms.

Explanation:

For question 21: Mitosis has stages like metaphase where spindle fibers attach to chromosomes. Without spindle fibers (due to colchicine), chromosomes can't align properly (no metaphase), can't separate (no anaphase), so cell division stops.
For question 22: Eukaryotic mitosis has a nucleus (nuclear envelope breakdown and re - formation), multiple linear chromosomes. Prokaryotic binary fission: no nucleus, single circular chromosome. Binary fission might be simpler, no spindle fibers (as in mitosis), direct DNA replication and cell splitting.

Answer:

1. Mitosis is inhibited. Chromosomes can't align (no metaphase) or separate (no anaphase), cell division halts.
2. Binary fission: no nucleus (vs mitosis with nuclear events), single circular chromosome (vs multiple linear in eukaryotes), simpler process (no spindle - based chromosome movement like in mitosis).