[Campbell Biology P.292] According to the 'Evolution of Mitosis' section, what unusual chara... | Practice Question

According to the 'Evolution of Mitosis' section, what unusual characteristic is observed in the nuclear division of certain unicellular eukaryotes such as dinoflagellates and diatoms that makes them candidates for representing intermediate stages in the evolution of mitosis from binary fission?

  • A: Their nuclear envelope remains intact during cell division.
  • B: They primarily use a cell plate for cytoplasmic division.
  • C: Chromosome movement is solely facilitated by actin-like proteins, without microtubules.
  • D: They possess multiple circular chromosomes.

Explanation

The 'Evolution of Mitosis' section states: 'In both types dinoflagellates, diatoms, and some yeasts , the nuclear envelope remains intact, in contrast to what happens in most eukaryotic cells.' This unique characteristic is presented as evidence for them representing intermediate stages.