![]() ![]() Fungi, protozoa and humans, for instance, are eukaryotic, whereas bacteria are prokaryotic. Archaea and Bacteria) and eukaryotes (Greek karyon: nucleus). Other differences between viruses and cellular organisms include:Īs mentioned above, another modification of classifying cellular organisms is to divide them into prokaryotes (i.e. Viruses are not included in this classification as they are unique, acellular, metabolically inert organisms and therefore replicate only within living cells. Polysaccharide cell walls, where present, are generally either cellulose or chitin Ribosomes – 80 S (mitochondrial and chloroplast ribosomes are 70 S) Ribosomes behave more like eucarya when exposed to inhibitors Membrane vesicles such as lysosomes and peroxisomes presentįlagella consist of one protein, flagellinĬontains flagella that derive energy from proton pumpsįlagella have a complex structure with 9 + 2 microtubular arrangement Internal membranes, endoplasmic reticulum and Golgi apparatus present associated with protein synthesis and targeting Photosynthesis associated with membrane systems and vesicles in cytoplasmĬhloroplasts present in algal and plant cells No lipopolysaccharides or teichoic acids foundĮnergy metabolism associated with the cytoplasmic membrane Lipopolysaccharides and teichoic acids found Meiosis leads to the production of haploid cells (gametes), which can fuse Processes similar to bacterial conjugation enables exchange of genetic materialĮxchange of genetic information occurs during sexual reproduction. Transfer of genetic information occurs by conjugation, transduction and transformation (see Chapter 3) Reproduce asexually and spores are not found May contain extrachromosomal elements called plasmidsĬell division by binary fission – asexual replication only Two copies of each chromosome may be present (diploid)ĭNA associated with histone-like proteins Organization of the genetic material and replicationĭNA is contained with a membrane-bound nucleus. Table 2.2 Major differences among the three domains of life Bacteria Most bacterial colonies appear white or a creamy yellow in colour, and are fairly circular in shape.Table 2.1 Differential characteristics of major groups of organisms Being kept in one place, the resulting cells have accumulated to form a visible patch. ![]() Colour (pigmentation) – for example, white, buff, red, purple, etc.Įach distinct colony represents an individual bacterial cell or group that has divided repeatedly.Opacity – for example, transparent (clear), opaque, translucent (like looking through frosted glass), etc.Surface – how does the surface of the colony appear? For example, smooth, glistening, rough, wrinkled or dull.What is the magnified shape of the edge of the colony? Elevation – this describes the side view of a colony.Tiny colonies are referred to as punctiform. ![]()
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