أصبحت جاهزة
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تسلم حبيبي أبو البراء .
وانا بخير دامك بخير . والله يا الغالي انشغلت في أمور كثيرة اسئل الله أن لا يشغلنا عن طاعته.اترك تعليق:
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ما قصرتي يا اختي ابدعتي .لكـن عندي اسئلة وأريد لها اجوبة مباشرة أتمنا من الجميع افادتي بأقرب وقت.
الكتيريا التي تعيش في التربه هي
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البكتيريا الي تعيش في الهواء هي
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البكتيريا الي تعيش في الطعام هي
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البكتريا التي تعيش في الماء هي
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What is bacteria?
Bacteria is a single-celled organism which can only be seen through microscope. Bacteria comes in different shapes and the size of bacteria is measured in micro-meter (which is a millionth part of a meter). Bacteria are found everywhere and in all type of environments.
There are numerous types of bacterial in the world. Before the invention of DNA sequencing technique, bacteria were mainly classified based on their shapes, which is also known as Morphology, biochemistry and staining (which is either Gram Positive or Gram Negative). Now a day along with the morphology, DNA sequencing is also used in order to classify bacteria. (DNA sequencing also helps in understanding relationship between two types of bacteria if they are related to each other despite of their shapes). Along with the shape and DNA sequence, other things such as their metabolic activities, conditions required for their growth, biochemical reactions (i.e. biochemistry as mentioned above), antigenic properties, and other characteristics are also helpful in classifying the bacteria.
There are various groups of bacteria, which belong to same family and are evolved from same bacteria (ancestor). However, each types of bacteria posses its own characteristics (those which are evolved after separation from the original specie).
The Two Main Groups
Taking a big overview of bacteria, there are two main groups, the bacteria and the cyanobacteria. Bacteria include all of the commonly known species such as Escherichia coli (E. coli bacteria), Salmonella bacteria, Staphylococci, Listeria and the Clostridia. Cyanobacteria form a separate type of bacteria that are able to photosynthesise – they can also be called blue-green algae.
Cyanobacteria still exist in large numbers today but their importance in the development of life on Earth is due to their existence here millions of years ago. Cyanobacteria were very successful and grew everywhere. Their ability to photosynthesise created all the oxygen that is in our atmosphere today. Most living organisms today depend on oxygen and without cyanobacteria, it is very unlikely that this life would have evolved.
Types of Bacteria
There are seven main groups of bacteria, distinguished by their shape and the type of cell wall they possess. Four of the seven types make up the majority of all bacteria:
Gram positive cocci
Gram negative cocci
Gram positive bacilli
Gram negative bacilli
Cocci are spherical cells, bacilli are rod-shaped. Bacteria of either shape that have thick cell walls are termed gram positive because of the way they take up the Gram stain. Those with thin cell walls are termed gram negative. These four main types are described in more detail below.
There are also three other, more rare types of bacteria:
Spirochaetes: corkscrew-shaped bacteria that fall into three species, all of which cause specific diseases. Treponema bacteria cause syphilis and yaws, Leptospira bacteria cause leptospirosis and Borrelia bacteria cause Lyme disease.
Rickettsia: bacteria from the Rickettsiaceae family, which can only live and survive inside other living cells. One type causes the disease typhus.
Mycoplasma: bacteria that have no cell wall. These can infect humans and cause pneumoniaاترك تعليق:
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مشكورين جميعا لكن أتمنا منكم ذكر اسمائها مثلا
الكتيريا التي تعيش في التربه هي
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البكتيريا الي تعيش في الهواء هي
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شاكر لكم جميعااترك تعليق:
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salmonella clostrdium tatani /في الماء colifrom staphlococcus feaclis colstridum prefenges:sm188::sm188:اترك تعليق:
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أختي العزيزة : انا بغيتها بالانجليزي ربي يسعدك واشكرك على جهودك في المنتدى وانا ارى فيك قوة نابضه لهذا المنتدى وذلك من خلال مشاركاتك واجتهادك وتحياتي الكبيرة لكالتعديل الأخير تم بواسطة عاشقة الميكرو26; الساعة 01-03-2011, 09:03 PM.اترك تعليق:
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الشكر لكم جميعا
بس يا اختي زهره ما قلتي انواع البكتيريا.
هل هي هوائية او مائية او في الطعام او التراباترك تعليق:
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البكتريا هي
salmonella
shigella
vibrio cholerae
Escherichia coil
campylobacater
yersiniaاترك تعليق:
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