Question

Palmella stage of Ulothrix/Chlamydomonas is formed in response to
(a)Unfavorable environment
(b)Toxic chemical
(c)Water deficiency
(d)All of the above

Answer 1

Hint: Chlamydomonas transition from a motile organism to a non-motile type referred to as the palmella stage under certain conditions. The stage of palmella is formed under various conditions that don’t suit the organism.

Complete answer:
Under the unfavorable condition, the cell becomes nonmotile by pulling back its flagella then protoplasmic content separates into 2, 4, or 8 daughter protoplasts. In any case, the daughter protoplast neglects to build up their flagella. So they can't escape out. Rather than delivering out, the protoplast partitions into daughter protoplasts. The protoplasts of parent cell partitions make numerous daughter protoplasts yet they don't form zoospores. The parent cell wall gelatinizes to make adhesive sheath around daughter protoplasts. The Palmella stage is created because of the repeated division of the cells and the simultaneous disintegration of parent cell wall framing mucilage.
In the non-motile stage, vegetative divisions are conspicuous and motility is suppressed until unique motile regenerative cells are shaped. Negative conditions or unfavorable conditions incorporate water lack, a toxic compound, and so forth.

Additional Information:
The cell in which zoospores form is called zoosporangium. Zoosporangium is the cell into which zoospores are produced. A colonial aggregate of immobile non-flagellated individuals that occurs periodically during the life cycle or in response to increased medium firmness of certain flagellated green algae or plant-like flagellates.
So, the correct answer is, ‘All of the above’.

Note: Ulothrix is a genus of non-branching green filamentous algae, commonly found in both fresh and marine water. Its cells are usually as wide as long and thrive at low spring and winter temperatures. They get attached by a tweaked holdfast cell to the surfaces. Reproduction is typical of a vegetative nature.