Question

Circadian rhythms are genetically controlled phenomena where organisms are able to control behaviors, even in the absence of environmental cues, for a period of time approximating 24 hours. Paramecia feed and mate based on circadian rhythms. Plants open and close their stomata based on these genetic controls. Animals demonstrate periods of waking and sleeping that follow 24 hour trends, even without light cues. What is the likely explanation for the evolution of circadian rhythms?

A) Circadian rhythms evolved in a common ancestor to life, but was lost in prokaryotes.

B) Circadian rhythms evolved in a common ancestor to life and is present in all life forms.

C) Circadian rhythms evolved at least three separate times, in protists, plants, and animals.

D) Circadian rhythms evolved on the branch containing eukaryotes and are found in all eukaryotes.

Answer 1

The correct answer is D) Circadian rhythms evolved on the branch containing eukaryotes and are found in all eukaryotes.

Step-by-step explanation:

Answer 2

Answer: B) Circadian rhythms evolved in a common ancestor to life and is present in all life forms.

The circadian rhythms comes to play because of the evolution of different pathways and molecular mechanisms over the time in different species in relations to its environment and varying changes.

Step-by-step explanation:

Circadian clocks are believed to have evolved in parallel with the geological history of the earth, and have since been fine-tuned under selection pressures imposed by cyclic factors in the environment.

Evolution has selected a system of two intertwined cell cycles: the cell division cycle (CDC) and the daily (circadian) biological clock. The circadian clock keeps track of solar time and programs biological processes to occur at environmentally appropriate times. One of these processes is the CDC, which is often gated by the circadian clock.