Which one of the following cellular parts is correctly described ?
1. Thylakoids - flattened membranous sacs forming the grana of chloroplasts
2. Centrioles - sites for active RNA synthesis
3. Ribosomes - those on chloroplasts are larger (80s) while those in the cytoplasm are smaller (70s)
4. Lysosomes - optimally active at a pH of about 8.5

Match the following and select the correct answer :

Extranuclear chromosomes occur in:

In a eukaryotic cell, the two organelles that can transform energy are:
1. bound by a single membrane
2. parts of the endomembrane system
3. present only in the plant cells
4. semi-autonomous