If an organelle was completely autonomous, it would not be endosymbiotic, which is required for an organelle. It wood be parasitic, infecting a host cell. Mitochondria and chloroplasts are known as semi autonomic organelles. It is because they have their own DNA, mRNA, tRNA & ribosomes and can reproduce independently. These organelles can grow and divide to reproduce themselves, but they are not completely autonomous because they depend on other parts of the cell for their internal components.

Fully autonomous organelle in cell is ===>Nucleus .....................
Semi-autonomous organelles in cell ==> (1)mitochondria &(2)chloroplast...............................

Autonomous Organelles in Cells

Autonomous organelles are specialized structures found within cells that have their own DNA and can replicate independently of the cell's nuclear DNA. These organelles play crucial roles in various cellular processes and are essential for the overall functioning and survival of the cell. The two main types of autonomous organelles found in cells are mitochondria and chloroplasts.

I. Mitochondria:
Mitochondria are double-membraned organelles commonly referred to as the "powerhouses" of the cell. They are responsible for generating ATP (adenosine triphosphate), which is the primary energy currency of the cell. The mitochondria have their own circular DNA, known as mitochondrial DNA (mtDNA), which contains genes necessary for the organelle's functions.

Key points related to mitochondria:
- Mitochondria are present in most eukaryotic cells, including animal and plant cells.
- They have an inner and outer membrane, with the inner membrane being highly folded into structures called cristae, increasing the surface area for ATP production.
- Mitochondria are involved in cellular respiration, where glucose is broken down to produce ATP through a series of metabolic reactions.

II. Chloroplasts:
Chloroplasts are organelles found in plant cells and some protists, responsible for carrying out photosynthesis. They contain their own DNA, known as chloroplast DNA (cpDNA), and are involved in capturing sunlight energy and converting it into chemical energy in the form of glucose.

Key points related to chloroplasts:
- Chloroplasts are green-colored due to the presence of chlorophyll pigments.
- They have a double membrane and contain a network of membranes called thylakoids, which are stacked to form grana.
- Chloroplasts are involved in the process of photosynthesis, where carbon dioxide and water are converted into glucose and oxygen using light energy.

III. Similarities and Evolutionary Significance:
Both mitochondria and chloroplasts are believed to have originated from ancient prokaryotic cells through a process called endosymbiosis. This hypothesis suggests that these organelles were once free-living bacteria that were engulfed by ancestral eukaryotic cells and formed a symbiotic relationship. Over time, these organelles became integrated into the host cell and lost some of their independent functions.

Key points related to similarities and evolutionary significance:
- Both mitochondria and chloroplasts have their own DNA and can replicate independently of the cell's nuclear DNA.
- They are believed to have evolved from bacteria that were engulfed by ancestral eukaryotic cells.
- This endosymbiotic theory is supported by the presence of similar structures and processes in both organelles and certain similarities in their DNA.

In conclusion, autonomous organelles in cells, such as mitochondria and chloroplasts, are essential for various cellular processes. They have their own DNA and can replicate independently, suggesting an evolutionary history involving endosymbiosis. Mitochondria generate ATP through cellular respiration, while chloroplasts carry out photosynthesis. Their presence and functions contribute significantly to the overall functioning and survival of eukaryotic cells.