1:
- Nucleus: Controls cell activities and contains genetic material (DNA).
- Mitochondria: Produces energy (ATP) through cellular respiration.
- Endoplasmic reticulum: Involved in protein and lipid synthesis.
- Golgi apparatus: Modifies, sorts, and packages proteins for transportation.
- Lysosomes: Contain enzymes for breaking down waste and cellular debris.
- Vacuoles: Stores water, nutrients, and waste materials.
- Chloroplasts (in plant cells): Carry out photosynthesis to produce glucose.
- Ribosomes: Responsible for protein synthesis.
- Cell membrane: Regulates the movement of substances in and out of the cell.
- Cell wall (in plant cells): Provides structural support and protection.
2: The endosymbiotic theory proposes that certain organelles, such as mitochondria and chloroplasts, were once free-living prokaryotic organisms that became incorporated into ancestral eukaryotic cells through symbiotic relationships. This theory suggests that these organelles evolved from ancient prokaryotes that were engulfed by early eukaryotic cells and established a mutually beneficial relationship.
Evidence supporting the endosymbiotic theory includes:
- Mitochondria and chloroplasts have their own DNA, which is circular like that of prokaryotes.
- Mitochondria and chloroplasts replicate independently within cells, similar to prokaryotes.
- Both organelles have double membranes, which may have originated from the engulfing process.
- Mitochondria and chloroplasts produce their own proteins using ribosomes that closely resemble bacterial ribosomes.
- DNA sequence analysis has shown similarities between the genes of mitochondria and chloroplasts and those of bacteria.
- Cyanobacteria, which are similar to the ancestors of chloroplasts, can live as free-living organisms and also establish symbiotic relationships with other organisms.
1: What is function of the following organelles
2: What is the endosymbiotic theory? What evidence supports it?
1 answer
1 answer