Gram staining is a bacterial cell staining technique developed by Hans Christian Gram in 1884. Composition of cell wall plays a very important role in classification of bacteria. Due to its rigid nature, the cell wall provides shape and protection to the bacterial cell. Cell WallĪll bacteria have a cell wall made of peptidoglycan. The mutant forms of these bacteria that do not have capsule, do not cause disease as well. More importantly for us, this capsule is a major virulence factor in the major disease-causing bacteria, such as Escherichia coli and Streptococcus pneumoniae. This layer protects bacteria from drying and also from getting engulfed by bigger organisms. Some bacteria have an outermost layer made of polysaccharides, called capsule. Following illustration shows the structure of a typical bacterial cell: Structure of BacteriaĪlthough bacteria are found in many shapes, the typical bacterial cell structure remains same. For example, the curd you eat is made by and contains a wide variety of bacteria like Lactobacillus acidophilus, Lactococcus lactis, Lactococcus lactis cremoris etc. In contrast most of the bacteria are actually useful for us in one way or the other. But truth is that only some bacteria are harmful for us. They are found in large number of shapes but typically they are circle or spherical (coccus), rod-like (bacillus), spiral or filamentous.įor most people the word bacteria refers to something horrible. Therefore, they are one of the oldest living organisms on the Earth. There are evidences suggesting that bacteria were in existence even 3.5 billion years ago. These microorganisms are found in soil, water, deep in the oceans, hot springs, radioactive waste - practically everywhere including the most extreme conditions! Bacteria also live in symbiotic and parasitic relationship with other organisms. The nocturnal lifestyle can be a cause of night shift jobs, a social life that always occurs at night, such as drinking and partying, or worse, may be the cause of sleeping problems such as insomnia.ġ.“Diurnal” came from the word “diurnus” meaning “daily” or “day” while “nocturnal” came from the word “nocturnus” meaning “belonging to the night.”Ģ.Nocturnal species have special senses which are active at night while diurnal species are best functioning during the day.ģ.Humans can be nocturnal or diurnal depending on external factors, such as occupation, lifestyle, or at worst is by a disease.Share on Twitter Facebook WhatsApp What is Bacteria?ĭefinition: Bacteria are single-cell, prokaryotic microorganisms.īacteria are present everywhere on the planet Earth, including on the bodies of other organisms and inside them too. She or he is sometimes referred to as a vampire or Dracula. In humans, when a person is said to be nocturnal, she is wide awake and active at night. Plants can also be nocturnal or diurnal, but this depends on the season of pollination where the insects visit them. More examples of these animals are beavers, squirrels, rabbits, and skunks. We humans are also diurnal, but some people function best at night. Most of the animals like mammals, birds, reptiles, and insects are diurnal. While they are active in the daytime, they sleep during the night. “Diurnality,” on the other hand, is a term for animals’ behavior that are active during the day. A lot of nocturnal animals usually have bigger eyes than their head and body. Some can only do their tasks at night, such as bats. These animals have a high sense of olfaction or smelling and hearing. In animals, “nocturnality” is a word describing their behavior for these creatures who are active during the night time and sleeping during the day. “Diurnal,” on the other hand, is a word which comes from the Latin word “diurnus” meaning “daily” or “day.” It is a word describing living things which are active during the day whether animals, plants, or humans as well. “Nocturnal” is a term used which comes from the Latin word “nocturnus” meaning “belonging to the night.” It is a word which describes organisms that are active in the night, such as animals and plants. So it depends and varies a lot on each person. Some people love working in the daytime and cannot tolerate working during night shifts. I personally love working at night, and I’m always sleepy during the day. It is interesting to note that we have distinct and preferred times of the day. Some are at their best during the morning while others are at their best during the night. Humans and animals function in different settings and times of the day.
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