Question

elfy the nape of Bacterial Cell Most bacteria are found in three basic shapes shiritum spiral os helical), bacillus (rod), and coccus (round or spherical) (Fig. 13.4), Bacilli may form leng filamento acci mayorm clusters or chains. Some bacteria form endospores. An endospore contains of the venetic material encased by heavy protective spore coats. Spores survive unfavorable conditions and germinate to form vegetative cells when conditions improve Observation: Shape of Bacterial Cell 1. View the microscope slides of bacteria on display. What magnification is required to view bacteria? VODY 7000X spiritum, bacilli coca 2. Using Figure 13.4 as a guide, identify the three different shapes of bacteria 3. Do any of the slides on display show bacterial cells with endospores? What is an endospore, and why does it have survival value? Figure 13.4 Diversity of bacteria. a. Spirillum, a spiral-shaped bacterium. b. Bacilll, rod-shaped bacteria, c. Cocci, round bacteria Edesche Getty Images Eye of Science Science Source SOMATIScience Source BE SEM 13,300x a. Spiritum Spin b. Bu Escherichia co c. Cocci SEM 6 250x Streptococcus thermophilus volutons Cyanobacteria Cyanobacteria were formerly called blue-green algae because their general growth habit and appearance through a compound light microscope are similar to green algae. Electron microscopic study of cyanobacteria. however, revealed that they are structurally similar to other bacteria, particularly other photosynthetic bacteria Although cyanobacteria do not have chloroplasts, they do have thylakoid membranes, where photosynthesis occurs Observation: Cyanobacteria Gloeocapsa 1. Prepare a wet mount of a Gloeocapsa culture, if available, or examine a prepared slide, using high power (45x) or oil immersion (if available). The single cells adhere together because each is surrounded by a sticky, gelatinous sheath (Fig. 13.5). 2. What is the estimated size of a single cell? Laboratory 13 Microbiology 151 13-5

Answer 1

Obseruation, shape of Bacterial cell t 4008 to looox magnification is required O to view bacteria, 2. Spirillum (spirilluno volutons) spiral or helical shape bacilli (Escherichia coli) Rod shaped cocci (Streptococcus thermophilus) Round or avoid in shape in form of kairs or chains. W3C 3. Bacilli forms endospores. Endospore - An endospore is a dormant, tough, and non reproductive structure produced by some bacteria, Endospore formation is usually triggered by a lack of metrients, and usually occurs in Bacilli & Clostridium. The primary function of endospores is to ensure the survival of a bacteria through periods of environmental stress, 59 Qudospeu hаvе лишvol value.