Question

Which one carries extranuclear genetic material?
A. Plastids
B. Ribosomes
C. Chromosomes
D. Golgi bodies

Answer 1

Hint: They are also called semi-autonomous organelles meaning they can replicate themselves independently of the nucleus. One of them is organelle found in the plant cells and other helps in the generation of energy for cells.

Complete answer:
All the genetic information in a cell initially was confined to the DNA in chromosomes of the cell nucleus but now it is known that a small circular chromosome called cytoplasmic or extra nuclear DNA is located in the two types of organelles found in the cytoplasm of cells. In eukaryotic cells, DNA is inside the nucleus associated with histone proteins. This nucleus is bounded by a nuclear envelope and the DNA present at the nucleus is known as extra nuclear DNA. In eukaryotes the extra nuclear DNA is present in chloroplast and Mitochondria.
Plastids is a double membrane organelle in the plant cell and algae. They are of Leucoplasts, chloroplast and chromoplast. Plastids contain pigments used in photosynthesis. The pigments like chloroplast and carotenoid pigments are found in the chloroplast. The pigments present in them describe the colour of the cell. The double stranded DNA is circular in plastids. The organelle like chloroplast is known as semi- autonomous organelle as they contain DNA, mRNA and ribosomes and can synthesize proteins. They carry some genetic information in the form of DNA and can replicate on their own. Mitochondria also contain their own genetic material and have genes which help in making the protein functional for mitochondria like plastids (chloroplast). Golgi Bodies is a single membrane organelle helpful in the production of glycolipids and glycoproteins. Ribosomes constitute protein and RNA. It is the important organelle for protein synthesis. Chromosomes are threads in which DNA is tightly bound inside the nucleus. The DNA is bounded by proteins called histones which help in support. DNA replication is ensured by the chromosomes.

Hence, the correct answer is option (A).

Note: The DNA molecules found in chloroplast and mitochondria are small and circular which resembles the DNA of prokaryotes. The presence of 70s Ribosomes in chloroplast and mitochondria supports the endosymbiont theory meaning chloroplast and mitochondria are free living prokaryotes.