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6 days ago · Unlike other morphotypes with fixed shapes, pleomorphic bacteria can modify their structure to optimize survival, an attribute that is advantageous in fluctuating environments. For example, Mycoplasma species, known for their lack of a rigid cell wall, demonstrate significant pleomorphism.
Bacteria are classified by shape into three basic groups: cocci, bacilli, and spirochetes (Figure 2–1). The cocci are round, the bacilli are rods, and the spirochetes are spiral-shaped. Some bacteria are variable in shape and are said to be pleomorphic (heterogeneous shape). The shape of a bacterium is determined by its rigid cell wall.
Sep 22, 2024 · List the three basic shapes of bacteria. List and describe 5 different arrangements of cocci. Define and give the abbreviation for the metric unit of length termed micrometer and state the average size of a coccus-shaped bacterium and a rod-shaped bacterium. List and describe 2 different arrangements of bacilli.
- Cocci
- Bacilli
- Spiral-Shaped Bacteria
- Pleomorphic Bacteria
Cocci appear in several characteristic arrangements such as diplococci (cocci in pairs), streptococci (cocci in chains), tetrads, staphylococci (cocci in grape-like clusters), andsarcinae. These arrangements are determined by whether the daughter cells stay together following division. Diplococci Diplococci arise when cocci divide and remain togeth...
These are not arranged in patterns as complex as cocci; most occur singly or in pairs (diplobacilli). But some species, such as Bacillus subtilis, form chains (streptobacilli); others, such as Beggiatoa and Saprospira species, formtrichomes(which are similar to chains but have a much larger area of contact between the adjacent cells). Rod-shaped or...
Spiral bacteria have a variety of curved shapes. Bacteria with less than one complete twist or turn have a vibriod shape, whereas those with one or more complete turns have a helical shape. Spirilla are rigid helical bacteria, whereas spirochetes are highly flexible. Spirilla (singular: spirillum) are rigid, wavy-shaped curved bacteria, and spiroch...
Some bacteria are variable in shape and are said to be pleomorphic (heterogeneous shape). Some common pleomorphic pathogenic bacteria are; Other unusual shapes of bacteria Some bacteria do not fit in any of the above-mentioned categories and have spindle or irregular, lobed shapes. Some of these bacterial shapes are; Bacillus arranged in a rosette ...
Aug 10, 2022 · The three basic bacterial shapes are coccus (spherical), bacillus (rod-shaped), and spiral (twisted), however pleomorphic bacteria can assume several shapes. Cocci (or coccus for a single cell) are round cells, sometimes slightly flattened when they are adjacent to one another. Bacilli (or bacillus for a single cell) are rod-shaped bacteria.
The round shaped bacteria are called cocci, the rod shaped ones are called bacilli, spiral shaped ones are spirilla, and sometimes the same bacteria can have multiple forms, in which case they’re called pleomorphic.
Pleomorphic – pleomorphic organisms exhibit variability in their shape. There are additional shapes seen for bacteria, and an even wider array for the archaea, which have even been found as star or square shapes. Eukaryotic microbes also tend to exhibit a wide array of shapes, particularly the ones that lack a cell wall such as the protozoa ...
