identify the process dependent in the picture given below a name the organism that divides by the above process be compared the above process with multiple fission si state the type of reproduction in our process and define it second part differentiate between fission in amoeba and leishmania what are plant hormones for different types of plant hormones and state their function briefly
Answers
Answer:
Explanation:
The shape and form of protozoan parasites are inextricably linked to their pathogenicity. The evolutionary pressure associated with establishing and maintaining an infection and transmission to vector or host has shaped parasite morphology. However, there is not a ‘one size fits all’ morphological solution to these different pressures, and parasites exhibit a range of different morphologies, reflecting the diversity of their complex life cycles. In this review, we will focus on the shape and form of Leishmania spp., a group of very successful protozoan parasites that cause a range of diseases from self-healing cutaneous leishmaniasis to visceral leishmaniasis, which is fatal if left untreated.
Shape and form of Leishmania
Like many protozoan parasites, Leishmania have a digenetic life cycle involving both a mammalian host and an insect vector. Leishmania parasites exhibit a variety of different cell morphologies and a number of cell types (developmental forms) that are adapted to either the host or the vector. As seen with other parasites such as Plasmodium and trypanosomes, some of these developmental forms are proliferative, whereas others are quiescent and pre-adapted for transmission to the next host [1–4]. Much of the interpretation of cellular form and function in Leishmania species is derived from the more studied basic cell biology of trypanosomes. While this is a natural transfer of knowledge, one has to remain vigilant to the fact that unrecognized differences may exist between the two pathogen systems, even in their basic biology.
Leishmania have two major different cell morphologies, exemplified by the promastigote morphology in the sand fly and the amastigote morphology in the mammalian host (figure 1a). The basic cellular architecture is however conserved between the two Leishmania cell shapes and is defined by cross-linked sub-pellicular corset microtubules. This array is maintained throughout the cell cycle, so cell division relies on the insertion and elongation of microtubules into the existing array. Housed within the cell are the nucleus and a set of single-copy organelles such as the mitochondrion and the Golgi apparatus. Anterior of the nucleus is the kinetoplast, the mass of concatenated mitochondrial DNA which is directly connected to the basal body from which the flagellum extends [5–8]. At the base of the flagellum is an invagination of the cell membrane forming a vase-like structure called the flagellar pocket, which is important in these parasites as it is the only site of endocytosis and exocytosis and is hence a critical interface between the parasite and its host environment [9].
Figure 1.
Figure 1.
Schematic of promastigote and amastigote morphologies and the Leishmania life cycle with the different cell types highlighted. (a) Promastigote and amastigote morphologies aligned along the posterior anterior axis with key structures in the cells indicated. ...