Nearly all plant cells and many bacteria are surrounded by a cell wall. However, the roles these walls play in cell division dif
fer dramatically. In plants, the wall is sufficiently rigid so that in most cells, constriction of a ring of proteins could not cause the wall to fold in and eventually pinch off. Rather, a new plant cell wall is produced between the daughter cells by the formation of a cell plate, which eventually joins with the existing cell wall. In contrast, in bacteria, the cell wall is sufficiently flexible to fold in during constriction of the FtsZ protein ring. Bacteria lack the distinct microfilaments and microtubules that dominate the cytoskeletons of plant and animal cells. However, bacteria contain proteins that are similar to actin (the building block of microfilaments) and tubulin (the building block of microtubules). The tubulin-like proteins in bacteria function in the formation of two daughter cells through binary fission.
In prokaryotes, constriction of a ring of________ cause infolding of the plasma membrane and cell wall during cell division (binary fission).
In plant cells, a network of________ functions in the formation of the cell plate.
In animal cells, a ring of________ constricts, creating a cleavage furrow.
Which two of these three have a similar mechanisms of cytokinesis or cell division?
a. animals and plants
b. animals and bacteria
c. plants and bacteria
1. In bacteria, the binary fission process takes place when the cytoskeletal structure of the bacteria are assembled to form the contractile ring in the centre of the cell. The contractile ring in bacteria is composed of the Z-protein which is a tubulin homolog.
2. Plants: the plants divide by the cell plate formation and not the contractile ring formation. This is mediated by the actin, tubulin and vesicle produced from the dictyosomes.
3. Animals: a contractile ring attached to the plasma membrane is formed which is composed of the F-actin and tubulin.
4. Since the bacteria and animal cytokinesis involves the formation of the contractile ring and thus the same mechanism of cytokinesis.
Between the 1st and 5th centuries AD, Indian art was influenced by the culture of ancient <u>Greece</u>. During this period, India was ruled by several foreign dynasties. The first among them were Greeks (called as Indo-Greeks) who had great artistic skills during the time. The Greek artistic influence can be seen in mathura School of art and Gandhara School of art--where the hands were Greek but ideas were Indian.
