Cell Biology and Structure

Genetic engineering mainly aims at the transfer of genes of desired protein products between the organisms. Lysosomes are the suicidal bags of cell that digest and remove the wear and tear organelles and molecules from the cell. Golgi body consist of flattened sacs stacked on each other, that serve to processes secretory and synthetic products from the ER and then transport the finished products into cell part or secretes them to the outside of the cell. Mitochondria are double membrane bound eukaryotic cell organelles that serve as the site for cellular respiration, produce an enormous amount of energy and therefore are also known as a power house of cell. Plasmids are low molecular weight extrachromosomal DNA that carries origin of replication, restriction sites and selectable markers to confer readily selectable phenotypic traits on host cells. Plasmids require very few genes for their own replication and rest of it can be deleted and foreign sequences can be added to the plasmid which in turn makes them a suitable candidate to serve as a vector for gene transfer. Thus, the correct answer is option C.

A. Cell necrosis - is a form of cell injury which results in the premature death of cells in living tissue by autolysis.

 B. Pinocytic activity - is a mode of endocytosis in which small particles suspended in extracellular fluid are brought into the cell through an invagination of the cell membrane, resulting in a suspension of the particles within a small vesicle

C. Programmed cell death is the death of a cell in any form, mediated by an intracellular program. PCD is carried out in a biological process, which usually confers advantage during an organism's life-cycle.

D. Cell senescence- is a phenomenon by which normal cells cease to divide

So, the correct option is ‘Programmed cell death’.

Sphaerosomes are small, spherical organelles found in plant cells that are specialized for the synthesis and storage of lipids.

Cofactor is a nonprotein part of the enzyme. It can be metal ions or the organic chemical. The cofactors which are organic chemicals are known as coenzyme. These are loosely attached to the apoenzyme. The tightly bound coenzymes are prosthetic group. 

The sieve tubes are supporting cells in the conducting tissue of the plant and are characterised by the absence of a nucleus. 

Chloroplasts are very similar to mitochondria but are found only in the cells of plants and some algae.ATP synthesis is present in both Mitochondria and Chloroplast and the outer membrane has not more surface in both.

The shaft of cilia and flagella consists of an external sheath, semi fluid matrix and an axoneme. Axoneme has 9+2 fibrillar arrangement, comprising of nine peripheral doublet microtubule fibrils and two central singlet microtubule fibrils, central sheath, linkers and spokes. Certain flagella possess lateral hairs called flimmer filaments. Such flagella are called tinsel Flagella.

A basal body (synonymous with basal granule, kinetosome and in older cytological literature with blepharoplast) is an organelle formed from a centriole, and a short cylindrical array of microtubules. It is found at the base of a eukaryotic undulipodium (cilium or flagellum) and serves as a nucleation site for the growth of the axoneme microtubules. Centrioles, from which basal bodies are derived, act as anchoring sites for proteins that in turn anchor microtubules within centrosomes, and are known as the microtubule organizing center (MTOC).

Centrosome is composed of two centrioles lying at right angles to each other. Each centriole has a cartwheel constitution. There is a whorl of nine peripheral triplet fibres of tubulin tilted at an angle of 40 degrees. In cilia and flagella also the cartwheel structure is present but the fibrils have 9+2 arrangement- peripheral doublet fibrils are tilted at an angle of 10 degrees.