ER Structure: RER vs. SER Key Difference
The Endoplasmic Reticulum (ER) is a network of membranes within eukaryotic cells. It exists in two forms:
- Rough Endoplasmic Reticulum (RER): Studded with ribosomes on its outer surface. Involved primarily in protein synthesis and modification.
- Smooth Endoplasmic Reticulum (SER): Lacks ribosomes. Involved in lipid synthesis, detoxification, and calcium storage.
Identifying the Main Distinction
The presence or absence of ribosomes is the fundamental difference distinguishing RER from SER. Ribosomes attached to the RER surface give it a 'rough' appearance and enable it to synthesize proteins destined for secretion or insertion into membranes.
Therefore, the key difference lies in the attachment of ribosomes.
The correct option is 4. ribosomes.
Important Questions from Genetics and Evolution
Ancient hominids who are placed in the category of homo sapiens were -
A. Ergaster line
B. Cro - Magnon
C. Neanderthal
D. ProconsulsEach polynucleotide of DNA is made up of small units called _____________.
A group of similar organisms which are genetically distinct and reproductively isolated, is called a/an -
The adaptor molecule in the process of translation is :
All human beings have ________ pairs of chromosomes in the nuclei of their cells.
