bacteria culture

A bacterial culture grows at a rate proportional to the number of bacteria present. If the size of the culture becomes 7 times every one hour, then how long does it take for the culture to become 8 times? => 128 minutes or 67 minutes or 13 minutes or 155 minu..

The equation w = e t 3 + 3 e t + 4 represents the change in mass ' w ' (in grams) of a bacteria culture as time ' t ' (in hours) changes. Find the least mass of the culture. => 2 grams or 6 grams or 4 grams or 3 grams..

. Such bacteria are found - where grasses, cereals are grown. They fix atmospheric nitrogen and make it available to crops. Fixation of nitrogen by such bacteria may occur naturally in very ideal situation. But such fixation process may have to be enhanced by external applicatio..

Earlier E. coli was used as a host for the recombinant DNA. Now Bacillus subtilis and yeast are also being used. The bacteria to be used as hosts should be without plasmids. Their wall is made permeable by treatment with calcium chloride or lysozyme. The recombinant DNA is added to ..

Introduction of Recombinant DNA into Host - Earlier E. coli was used as a host for the recombinant DNA. Now Bacillus subtilis and yeast are also being used. The bacteria to be used as hosts should be without plasmids. Their wall is made permeable by treatment with calcium chloride or lyso..

, a French scientist, injected aged culture of cholera bacteria into healthy chicken. Such an aged culture was too weak to cause disease in the chicken. When fresh culture of fowl, cholera bacteria was injected into those chicken the disease did no..

Gene Cloning - Gene cloning refers to the production of a large population of a DNA fragment in pure form. Gene cloning involves the formation of a recombinant DNA and its introduction into an appropriate host, such as Escherichia coli or Bacillus subtilis. The host used should be without plasmids...

Designer Plants - Many years ago, Frederick Steward and his co-workers cultured cells from carrot plants and induced some of them to develop into small embryos. Some of these embryos grew into whole plants. Today, researchers routinely regenerate crops, plants and many other plant species..

Blender Experiment by Hershey and Chase - Hershey and Chase devised an experiment in the year 1952 with two different preparations of T 2 phage. T 2 phage contains both DNA and proteins. It is possible to examine which of the two components has the information to programme for the production of mor..

Advantages - The offsprings are genetically identical and therefore advantageous traits can be preserved. Only one parent is required which eliminates the need for special mechanisms such as pollination, etc. It is faster. For example, bacteria can multiply every 20 minutes. This helps th..