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How are unicellular organisms and multicellular organisms similar? How are they different?

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  • One important distinction here is whether we're talking about prokaryotes, i.e. organisms without a complex cell structure, and/or eukaryotes, organisms that have nuclei and other structures. This would significantly affect the comparison.
  • However, generally speaking, we can say that unicellular and multicellular organisms are alike in that they exhibit all the functions of life, such as a metabolism and reproduction, they contain DNA and RNA, they can exhibit a wide range of lifestyles, and they are essential to almost every ecosystem that we currently know of.


  • Unicellular organisms can reproduce faster and in greater numbers. Some of them are also capable of actually sharing DNA between living individuals, which is impossible for more complex life without technological intervention.
  • Multicellular organisms are almost always larger.
  • Unicellular organisms are more commonly found in extreme environments; the archaea, the third domain of life, counts among its members a number of "extremophiles" - single-celled organisms that thrive in environments of extreme heat, acidity, salinity, etc.
  • Multicellular organisms typically experience severe stress or death if a certain number of cells die or are separated from the group; unicellular organisms have no comparable problem.
  • Multicellular organisms require more food and living space and typically occupy a higher link in the food web.
  • Multicellular organisms may be better equipped to survive a harmful DNA mutation due to redundancy in other cells, but they are also at risk of cancer and other related diseases that have no comparison in the unicellular organism.

gurveer202 | Student

deez nutz


madisoncox943 | Student

They are the same because they can go without a cell structure.

They are different because they have a life without technological intervention.

pammy-bruhh03 | Student

i want to know the same thing i am in 6th grade and i have a group project and i need to know how they are different and  alike if anybody could please help out i would feel happy....i think they are different because Unicellular is ONE SINGLE cell and Multicellular has multiple cells in a organism

malkaam | Student

The major similarity between unicellular and multicellular organisms is that both of them contain cell/cells. Unicellular organisms contain one cell and all of their functions are based on that one cell whereas multicellular organisms contain more than one cell and there functions are divided amongst different cells like nervous cells, cardiac muscle cells etc.

Another similarity is that both of them carry out the same functions like consumption of food, respiration and getting rid of metabollic wastes etc.

Another difference is that unicellular organisms are smaller as compared to multicellular organisms. Example of unicellular organisms is amoeba, bacteria etc. Example of multicellular organisms are humans, most plants and animals.

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