Question

Which of these structures are more similar in Escherichia coli and Chlamydomonas
(a) Cell wall
(b) Cell membrane
(c) Ribosomes
(d) Chromosomal organization

Answer 1

Hint: Generally a cell contains nucleoplasm and protoplasm. Both protoplasm and nucleoplasm constitute cytoplasm. The layer that surrounds the cytoplasm is one of the similar structures found in prokaryotes and eukaryotes.

Complete answer:
Escherichia coli is a unicellular organism that is commonly found in human intestines. It is a prokaryotic organism whereas Chlamydomonas belong to the kingdom Plantae and class algae which are prokaryotic organisms. In both of these organisms, the cell structure that is similar is the cell membrane made up of a branched-chain of lipids. Cell walls in both organisms have different chemical and structural organizations and ribosomes in prokaryotes are of 70s type and in eukaryotes 80s type. The prokaryotic chromosomal organization is seen in E.Coli and eukaryotic chemical organization is seen in Chlamydomonas.

Additional Information: - Cell membrane consists of lipids that are arranged in a bilayer within the cell membrane and are arranged with the hydrophilic head towards the outer side and the hydrophobic tail towards inside the cell.
- Phosphoglycerides are the main lipid components present in the cell membrane
- Proteins and carbohydrates are also present in the cell membrane
- Membrane proteins are classified into integral proteins and peripheral proteins depending on the location and ease of extraction.
- One of the most important functions of the cell membrane is to transport molecules in and out of the cell

So, the correct answer is ‘cell membrane’

Note: A specialized differentiated form of the cell membrane that is a characteristic feature of prokaryotes is mesosome which is essentially an infolding of the cell membrane
The fluid mosaic model was the improved model of the cell membrane proposed by Singer and Nicolson in 1972.