AP BIOLOGY

Detailed explanation-1: -The chloroplast genome typically contains four copies of rRNA genes, a number of tRNA genes, at least three subunits of prokaryotic RNA polymerases and some other protein-coding genes such as ribosomal proteins, thylakoid proteins and the large Rubisco subunit (Palmer, 1985).

Detailed explanation-2: -Chloroplast DNA (cpDNA) is the DNA located in chloroplasts, which are photosynthetic organelles located within the cells of some eukaryotic organisms. Chloroplasts, like other types of plastid, contain a genome separate from that in the cell nucleus.

Detailed explanation-3: -Chloroplasts (members of the plastid family) and mitochondria are central to the energy cycles of ecosystems and the biosphere. They both contain DNA, organized into nucleoids, coding for critical genes for photosynthetic and respiratory energy production.

Detailed explanation-4: -From chromoplast preparations obtained fromNarcissus flowers, a DNA was isolated which resembles the DNA from chloroplast preparations. Both DNAs have a density in CsCl of 1.697 g cm−3, very similar to that of nuclear DNA (1.698 g cm−3).

Detailed explanation-5: -The DNA molecules found in mitochondria and chloroplasts are small and circular, much like the DNA of a typical bacterium. There are usually many copies of DNA in a single mitochondrion or chloroplasts.