Why mitochondria and chloroplast are called semi autonomous organelles?

Answer 1

Semi-autonomous because mitochondrial replication is controlled by the cell.

Mitochondria retain only a portion of their genome. Another, larger, portion of its genome has been moved to the cell nucleus. Thus the reproduction is under the nucleus' control. This coordinates mitochondrial reproduction by responding to cell division and cellular physiological stresses, but not by the mitochondria's control. However the exact pathway for mitochondrial biogenesis is yet to be worked out.

The gene transfer theory of endosymbiosis:

Gene transfer from the mitochondrion into the nucleus

Answer 2

They retain their own DNA, which is separate from the DNA of the cell they are in.

They are only semi-autonomous because most of the functions of mitochondria are now incorporated into the cell DNA (and they therefore divide when the rest of the cell does).

Answer 3

An organelle being fully autonomous would mean that it is fully self-sustainable - requiring no assistance from the cell to function and reproduce.

The mitochondria is semi-autonomous because it is, in large, self-sustainable. The mitochondria has its own DNA (circular), Rhibosomes and the ability to make its own proteins.

The reason then, that it is not fully autonomous, is simply that is does not have contact with the external environment - this means that the mitochondria is dependent on its surroundings, to give to it, molecules for metabolism (via endocytosis and other membrane transport mechanisms).

So if you think about it in respect to evolution, the mitochondria once was a fully independent (autonomous) bacterium. Once engulfed by a eukaryotic cell, it was embraced due to its high E producing ability and in turn, the bacterium became part of the eukaryote cell and is now dependant on the cell but only to supply it with metabolites.

In short: It hasn't the ability to obtain and breakdown its own biomolecules

D students answer: "In can do everything on its own except get its own food"

Answer 4

Semi-autonomous because mitochondrial replication is controlled by the cell.

Mitochondria retain only a portion of their genome. Another, larger, portion of its genome has been moved to the cell nucleus. Thus the reproduction is under the nucleus' control. This coordinates mitochondrial reproduction by responding to cell division and cellular physiological stresses, but not by the mitochondria's control. However the exact pathway for mitochondrial biogenesis is yet to be worked out.

The gene transfer theory of endosymbiosis:

Gene transfer from the mitochondrion into the nucleus

Answer 5

because of their own genetic materials like DNA and can prepare their own required protein. DNA can decode into mRNA and mRNA will translated into proteins that is why they are semi autonomous

Answer 6

because of their own genetic materials like DNA and can prepare their own required protein. DNA can decode into mRNA and mRNA will translated into proteins that is why they are semi autonomous

Answer 7

In many single-celled eukaryotes, their growth and division is linked to the cell cycle. For example, a single mitochondrion may divide synchronously with the nucleus.In other eukaryotes (in mammals for example), mitochondria may replicate their DNA and divide mainly in response to the energy needs of the cell, rather than in phase with the cell cycle. It can occur during the S phase of the mitotic cycle and even through out the mitotic cycle.
In single cell algae the chloroplast and the mitochondria divide first before cytokinesis.
In many organisms, the mitochondrial genome is inherited maternally. This is because the mother’s egg cell donates the majority of cytoplasm to the embryo, and mitochondria inherited from the father’s sperm are usually destroyed. There are numerous inherited and acquired mitochondrial diseases.

Both inherited and acquired mitochondrial dysfunction is implicated in several diseases, including Alzheimer disease and Parkinson disease. The accumulation of mtDNA mutations throughout an organism’s life span are suspected to play an important role in aging, as well as in the development of certain cancers and other diseases.
The maternal inheritance of mtDNA has proved vital to research on human evolution and migration. Maternal transmission allows similarities inherited in generations of offspring to be traced down a single line of ancestors for many generations.

Research has shown that fragments of the mitochondrial genome carried by all humans alive today can be traced to a single woman ancestor living an estimated 150,000 to 200,000 years ago.

Answer 8

there is no importance of mitochondria as semi autonomous organelles

Answer 9

The word "autonomy" means "self-governing." Mitochondria and chloroplasts are called semi-autonomous because they can feed and "govern" themselves and do not necessarily need the cell.