Question

Name two organelles having their own genetic component.
A. Plastid , mitochondria
B. Golgi apparatus, cell wall
C. Chloroplast, leucoplast
D. None of the above

Answer 1

Hint: Chloroplast, leucoplast, amyloplast, aleuroplast and elaioplast are the different types of plastids found in plant and animal cells. There are certain plastids which have their own genetic component within them but not all of them. The cell wall is not a cell organelle.

Step by step answer:Cell is the structural and functional unit of life, in which the eukaryotic cell possesses nucleus and other membrane-bound organelles. Chloroplast and mitochondria are the double membranous cell organelle. These two cell organelle, are the only one which contains their own genetic component that is the DNA. The chloroplast is the chlorophyll-containing plastid which takes part in photosynthesis. Mitochondria is the cell organelle which plays an important role in cellular respiration.
All chloroplasts are plastid but not all plastids are chloroplast. Other plastids such as elaioplast, aleuroplast, and amyloplast do not contain their own genetic material that contains the DNA or the RNA.
Plastids are of three types that are chloroplast, leucoplast, and chromoplast. The chloroplast is the chlorophyll-containing pigment which takes part in photosynthesis. The chloroplast is a green plastid. Leucoplast is the colorless plastid and chromoplast is the plastid containing other pigments other than chlorophyll.
The colourless plastid leucoplast has an essential function in storing food. Under leucoplast, we have amyloplast, elaioplast and aleuroplast. Amyloplast store starch, elaioplast store oil or fat, and aleuroplast store protein. Mitochondria are the sites of aerobic respiration in which they produce cellular energy in the form of ATP, hence they are called as powerhouses of the cell. It is a double membranous cell organelle in which both the membranes have their own specific enzymes.
The matrix of the mitochondria possesses a single circular DNA molecule, a few RNA molecules, ribosomes (70S) and the components which take part in protein synthesis. Since it has its own genetic material, it is a self-replicating cell organelle and it divides by fission.
The mitochondria are not easily visible under the microscope until it is specifically stained. Mitochondria are stained by Janus green which is a greenish-blue stain. Plastids like chloroplasts are easily observed under the microscope as they are large.
The stroma enclosed by the membranes of the chloroplast contains enzymes that help for the Synthesis of proteins and carbohydrates along with small, double-stranded circular DNA molecules and ribosomes. Its chlorophyll pigments are present in the thylakoids.

Note: Ribosomes are the only cell organelle which are present in prokaryotic as well as eukaryotic cells. The prokaryotic ribosomes are (70S) and the eukaryotic ribosomes are (80S). But chloroplast and mitochondria being eukaryotic, possess (70S) ribosomes just like the one in prokaryotes.