Not all restriction enzymes necessarily cleave DNA at rotationally symmetric sites. For example, the recognition site of the restriction enzyme Bst XI is 5' CCA^NTGG, where the symbol ^ represents the cleavage site and N means any nucleotide. Make the simplifying assumptions that equal amouts of all four nucleotides exist in the human genome, and that its base sequence is random. How frequently would you expect to find Bst XI recognition sites in the human genome

The frequency of Bst XI recognition sites in the human genome is once every 65536 bases in the human genome.

The frequency of cutting in a random DNA sequence for a given restriction enzyme, F = once per every 4^n nucleotide bases.

Given the recognition site of the restriction enzyme Bst XI as 5' CCA^NTGG,

Therefore, the number of nucleotide bases, n in the recognition sequence of Bst XI is eight nucleotide bases i.e. CCA

Assuming that equal amounts of all four nucleotides exist in the human genome, and that its base sequence is random:

Using the formula,  frequency = 4^n

for Bst XI, n = 8

Frequency = once per 4⁸ nucleotide bases

Frequency = once per 65536 nucleotide bases

Therefore, the frequency of Bst XI recognition sites in the human genome is once every 65536 bases in the human genome.

Learn more about restriction enzymes at: link

The frequency to be expected in order to find Bst XI identification sites in the human genome would be:

- Bst XI will cleave the DNA on average once in 4096 base pairs: one out of 4096 DNA fragments will have compatible ends.

1. Number of bases = 6so, the probability of occurrence of the site with 6 different bases = (1/4)^6= 1/4096

Thus, It means the enzyme Bst XI will cut DNA at once in every 4096 bases.

Learn more about "bases" here:

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question#1

ans:

cell is the basic unit of organization of all living things. cells are often called the building block of life and it is the smallest unit of life. the study of cell is called cell biology. cell consists of cytoplasm enclosed within membrane, which contain bio-molecules such as proteins and nucleic acid.

two third of cell is water, which means that two-third of your whole body is water. the rest is the mixture of molecules, mainly proteins, lipids and carbohydrates.

question#2

ans:

organ:

an organ is a group of tissues specialized to form a functional unit. an example is the heart in animals.

organ system:

an organ system is a group of several organs whose functions are synchronized to release an effective action in a living organism. an example is digestive system.

question#3

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#4

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system—working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#5

our body works because of the interactions that happen between organs and organ systems.  

for example:  

the heart to regulate blood flow throughout the body. the blood carries oxygen and nutrients to the cells and carries carbon dioxide and waste away from the cells. body systems work together in maintaining a constant internal environment. when this balance is disrupted, the body systems may not function properly, and human health can suffer.   you start to feel bad.