1: What is function of the following organelles

Question

Rough Endoplasmic, reticulum, ribosome, Golgi body.
2: What is the endosymbiotic theory? What evidence supports it?

Answer 1

1:

- Rough Endoplasmic Reticulum: It is responsible for the synthesis and packaging of proteins. It has ribosomes attached to its surface, which give it a rough appearance. It helps in the folding and modification of proteins before they are transported to their final destination.
- Ribosome: These organelles are responsible for protein synthesis. They read the genetic information carried by mRNA (messenger RNA) and use it to assemble amino acids into a specific sequence to form a protein.
- Golgi Body (Golgi Apparatus): It is involved in the processing, sorting, and packaging of proteins and lipids. It receives proteins from the rough endoplasmic reticulum, modifies them, and then directs them to their appropriate destinations within or outside the cell.

2:

The endosymbiotic theory proposes that eukaryotic cells (cells with a nucleus) evolved from a symbiotic relationship between primitive prokaryotic cells (cells without a nucleus), specifically the engulfment of one prokaryotic cell by another. This theory suggests that mitochondria and chloroplasts, both organelles found in eukaryotic cells, were once free-living prokaryotes that were engulfed by ancestral eukaryotic cells.

Evidence supporting the endosymbiotic theory includes:
- Mitochondria and chloroplasts have their own DNA, which is circular like the DNA found in prokaryotes.
- The size and structure of mitochondria and chloroplasts resemble prokaryotes.
- These organelles replicate independently, similar to prokaryotes undergoing binary fission.
- Antibiotics that target prokaryotic ribosomes also affect the ribosomes within mitochondria and chloroplasts.
- The similarities between prokaryotes and mitochondria/chloroplasts in terms of membrane structure and composition support the theory of endosymbiosis.