Karyochoresis is that type of mitosis in which the nuclear membrane (karyotheca) does not disappear, but it persists throughout the cell division and it can be seen even at the telophase. During karyochoresis, the spindle formation is internal. After telophase, the parent nucleus undergoes centripetal constriction and divides into two daughter nuclei.

All these changes occur in G₂ phase and halts to complete this process.

They do not help in the storage and transport of lipids in plants. This function is performed by spherosomes. So, this is not the correct statement. 

Under high oxygen concentration, RUBP acts as RUBP oxygenase and performs photorespiration. 

 Nexins are also known as 'interdoublet links' . Nexin joins the adjacent doublets of the axoneme of the eukaryotic flagellum.

Huxley proposed that Protoplasm is the physical basis of life.

 Mesosome is the invagination of the plasma membrane. It has respiratory enzymes, so it helps in bacterial respiration.

Glyoxysome is the cell organelle which is surrounded by a single unit membrane and contains two major enzymes namely isocitrate lyase and maltase synthetase. Glyoxysomes were first discovered by Beevers (1961) and later on described in detail by R.W. Briedenbach (1967).

 At this concentration, the ribosomes combine in pairs, to form dimers, each of which has a sedimentation coefficient of 120 S.(�S� is the sedimentation coefficient & is also known as �Svedberg Unit� ).

 Yes, it is the general formula for unsaturated fatty acids.

Yes, the first discovered nucleic acid was named as nuclein.

 Centrifugation involves centrifugal force to separate substances from mixtures. Ultra centrifugation helps to separate biomolecules.

 Peroxisomes contain oxidative enzymes, such as catalase, D-amino acid oxidase, and uric acid oxidase. However the last enzyme is absent in humans, explaining the disease known as gout, caused by the accumulation of uric acid. Certain enzymes within the peroxisome, by using molecular oxygen, remove hydrogen atoms from specific organic substrates, in an oxidative reaction, producing hydrogen peroxide (H₂O₂, itself toxic).

Circular DNA is found in E. coli and mitochondria. Chloroplast also has circular DNA.

 Both Assertion and Reasoning are true and R is the correct explanation of A. If karyokinesis is not followed by cytokinesis the cell becomes multinucleate or coenocytic or syncytial. Striated muscle fibers show striations with many nuclei in their striations. It shows syncytial condition.