Multiple choice questions on microbiology bacteria mcq. Differential staining of bacteria on gram staining is due to a. Morphology, in biology, the study of the size, shape, and structure of animals, plants, and microorganisms and of the relationships of their constituent parts. The bacteria are microscopic in nature and are visible only under compound microscope. Wallless bacteria that can not replicate are referred to as. Morphological characteristics the major morphological characteristics of bacteria include. Microscopy has come a long way since leeuwenhoek first observed bacteria using handground lenses. The shape of bacteria is very characteristic to them. Virus structure forms of viruses virus structure types. The basic morphologies are spheres coccus and roundended cylinders bacillus. Structure of gram negative bacteria however they cannot be destroyed by freezing the food or water 22. However, some bacteria are variable in shape and have a single characteristic form. These bacteria may be spherical,cylindrical or spiral in shape. Pdf difference between gram positive and gram negative bacteria.
The term refers to the general aspects of biological form and arrangement of the parts of a plant or an animal. Snehal patel, assistant professor, sumandeep vidyapeeth, vadodara, gujarat, india. Endospores and flagella are some examples of morphological features of some bacteria. These bacteria ferment a variety of sugars to produce formic, butyric, and lactic acids. These bacteria are shaped like flate, square to rectangular box about 2 m to 4 m and only 0. If a cocci cell appear individually then simply it is called cocci. View 4 morphological characteristics of bacteria 2015v2. Although bacterial cells are much smaller and simpler in structure than eukaryotic cells, the bacteria are an exceedingly diverse group of organisms that differ in size, shape, habitat, and metabolism. The peptidoglycan layer is thick effect of dye do not retain the crystal violet dye, and react only with a counterstain, generally stain pink.
Much of the knowledge about bacteria has come from studies of diseasecausing bacteria, which are more readily isolated in pure culture. Some bacteria can cause diseases for human, animals and plants. These structures are thought to help cells attach to their target environment. These bacterial structures have a specific shape like a stick bacilli, spherical cocci, coma cholera bact. The usual bacteria that you see range in size from 0. This results in dental plaque and many bacteria can stick to tooth surfaces and cause decay once s. Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features this includes aspects of the outward appearance shape, structure, colour, pattern, size, i. Vibrio cholerae, the cause of cholera, also produces.
Endospores endospores are dormant forms of bacteria that can. Morphological and physiological characteristics of gemmiger. The types of microscope are i light or optical microscope ii phase contrast microscope. The rickettsial organisms in common with the elementary bodies of vaccinia.
Lipid a is identical for related bacteria is similar for all gramnegative enterobacteriaceae. Bacteria and archaea are classified by direct examination with the light microscope according to their morphology and arrangement. Morphology and classification of bacteria microbiology module microbiology notes fig. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
Morphological and physiological characteristics of. The morphological structures of the rickettsiae of epidemic and endemic typhus fever, rocky mountain spotted fever, and q fever are similar to one another and to certain bacteria. Morphology of flagella size 520m long, width17nm parts filament made of flagellin semirigid, forms a left handed helix and exits the cell hook acts as a sleeve from which the filament emerges transmits rotatory motion from basal body to filament basal body consists of m,s,p,l rings connected by a rod shaped structure in gram positive bacteria only 2 rings. When treated by antibiotics, bacteria usually experience changes in morphology that can lead to the development of amr. A group of four cells forming a flat square is called. The type of morphological appearance of these cells has also been associated with the pathogenicity of the organism. Let us learn about morphology and ultrastructure of a bacterial cell. Morphology and ultrastructure of a bacterial cell with diagram. Members of the bacteria show great variation, to some degree in structure, but especially in metabolic capabilities, habitat, and life histories. A number of bacteria characteristically store deposits of nutrient materials, usually phosphate, sulphur, carbohydrate or fat in structure called cytoplasmic inclusions or granules. Bacteria morphology questions and answers pdf free download in microbiology mcqs,interview questions,objective questions,multiple choice.
Alternatively, in the grampositive bacteria, the peptidoglycan forms extensively crosslinked multimolecular layers. Difference between gram positive and gram negative bacteria. Instead, their dna, a double strand that is continuous and circular, is located in a nucleoid. The o antigen distinguishes serotypes stains of a bacterial species e. In the inside of every bacteria cell is the cytosol, which is a fluid phase medium that contains a lot of the activity of the bacteria.
Under a microscope, which organism would appear as a grapelike cluster of round cells. Archaea were initially classified as bacteria, receiving the name archaebacteria in the archaebacteria kingdom, but this classification is obsolete. Bacteria are microscopic unicellular organism they are true living organism that belongs to the kingdom prokaryotes. Cyanobacteria classification, structure, treatment and. This reason motivated their affiliation to a separate order caudovirales lat. The life cycle of the virus is a series of steps that enable the virus to infect a host and replicate itself. It can be found in soil, air, water, and living bodies. Most cells have the capacity to store only one kind of material producing a characteristic inclusion which can be stained and microscopically observed.
In this work, we propose a strategy to study mutation in protein expression during morphological changes of bacteria under the impact of antibiotics. Jan 11, 2018 morphological characteristics the major morphological characteristics of bacteria include. Given that they are not bacteria, some of these organisms yeastlike fungi have characteristics associated with eukaryotic cells in that some have been shown to contain a nucleus and other essential organelles. Bacterial structure and morphology medical microbiology is science of studying microorganisms that are associated with human disease agents of infection include cellular organisms belonging to two of the three recently defined domains of life. Module morphology and classification of bacteria microbiology 4 notes 1.
The nucleic acid, the dna of a bacteria is present in the structure called the nucleoid. Print bacterial cell morphology and classification. Bacterial cell morphology, staining reactions, classification of bacteria the protoplast is bounded peripherally has a very thin, elastic and semipermeable cytoplasmic membrane a conventional phospholipid bilayer. Morphological characteristics of bacteria protocols for endospore stain, capsule stain, motility stab and wet mount.
Malditof characterization of protein expression mutation. Size of a spherical shape bacteria can be measures in diameter. They lack organelles such as chloroplasts and mitochondria, and they do not have the true nucleus found in eukaryotic cells. Nuclear membrane nucleolus dna single molecule cell division no. Endospores, capsules and flagella are three such examples. Bacteria bacteria diversity of structure of bacteria.
These are called pleomorphic corynbacterium, arthrobacter. The morphological study of bacteria requires the use of microscopes. In certain species of bacteria, the cells are arranged in pairs, clusters, chains, trichoma and filaments. The nucleoid is an irregularly shaped region that does not have a nuclear membrane. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Explore virus structure, structure of virus, viral structure types, and functions of virus structure. As these bacteria are found in large numbers in the intestinal tract, they are transmitted most often through foods, ground beef. The term anatomy also refers to the study of biological structure but. Introduction bacteria are characterized by the presence or absence of a number of different structures. Morphology and ultrastructure of a bacterial cell with. Bacterial structure characteristic gramnegative bacteria grampositive bacteria wall structure they have a thin lipopolysaccharide exterior cell wall. As studies have shown, development of symbiotic relationships between freeliving cyanobacteria and other eukaryotic plants results in morphological, physiological and biochemical modification thus causing a change to the original morphology, physiology and biochemical form of the bacteria. These microorganisms lack cell nuclei and are therefore prokaryotes.
It has its own cellular machinery for growth and metabolism. Bacterial morphological plasticity refers to changes in the shape and size that bacterial cells undergo when they encounter stressful environments. So, diplococcus is a cocci bacteria that is found in pairs. The cell envelope encloses the protoplasm, comprising the cytoplasm, cytoplasmic inclusions such as. During that period many of the bacteria that cause human disease were identified and characterized. Bacteria diversity of structure of bacteria britannica. Cover different classification schemes for grouping bacteria, especially the use of the gram stain 2. Although bacteria have evolved complex molecular strategies to maintain their shape, many are able to alter their shape as a survival strategy in response to protist predators, antibiotics, the immune response, and other threats. The core region is the same for a species of bacteria.
However, structure of proteinscapsid constituents differs considerably among various tailed phages. A procaryotic cellular microorganism, very small size, could be seen with a microscope parameter. Bacteria definition, shapes, characteristics, types. Bacterial classification, structure and function introduction the purpose of this lecture is to introduce you to terminology used in microbiology. Classification of viruses morphology and structure naked viruses non enveloped replication pathogenicity transmission of viruses virus tissue tropism. It was followed by the concept based on the type of nucleic acid, capsid form, presence. The morphological data presented suggest that this species has a rodshaped structure. When two cells are attach to each other even after dividing them in one plane is called as diplococci. There appear to be two groups of gemmiger, one producing primarily lactate and the other producing formate as major fermentation metabolites. The type of peptidoglycan is thus a reliable but only very broad biochemicalmorphological characterization of species in the domain bacteria. If cocci cells are arranged in long chain and remain attach to each other even after dividing them in one plan is called as streptococcus. Antimicrobial resistance amr is one of the most serious problems affecting public health and safety. Outside, and closely covering this, lies the rigid, supporting cell wall. A bacteria that lives in pairs has a diplo arrangement, with di meaning two.