One of the procedures for cloning foreign DNA segments takes advantage of restriction endonucleases such as HindIII that produce complementary single strand ends (sticky ends). These enzymes produce identical sticky ends on cleaved foreign DNA and on the vector DNA into which you insert your DNA. Assume you have inserted your favorite gene into the HindIII site of the Bluescript cloning vector with ligase, you amplified it in E. coli, and isolated a large quantity of the plasmid with the insert. How do you excise your favorite gene from the plasmid?

Restriction endonucleases are utilized to cut the deoxyribonucleic acid at a specific Restriction site.  HindIII is an example of Restriction endonuclease. The Restriction site of HindIII is as per the following:  

5'A*AGCTT3'

3'TTCGA*A5'   (* represents restriction site)

The Restriction endonuclease cuts the particular gene from the foreign DNA and produces numerous fragments with the sticky ends. The part of the outside DNA which contains the gene of intrigue or a particular gene is ligated with the plasmid.  

On the off chance that foreign DNA and plasmid DNA are separated by the same Restriction endonuclease, they will create sticky ends integral to one another. In this way, the segment of foreign DNA can be ligated to the plasmid DNA by the assistance of DNA ligase at the integral sticky end to shape a recombinant DNA.  

Additionally, by the assistance of the same Restriction endonuclease for example HindIII for this situation, the recombinant plasmid can be treated with a similar Restriction endonuclease to extract the ideal gene or gene of intrigue.

an individual’s sex (i.e., whether they are a male or female) is determined by the sex chromosomes. most people have two sex chromosomes, one that is inherited from their mother and one that is inherited from their father. typically, females have two x chromosomes (xx) and males have one x chromosome and one y chromosome (xy). conditions caused by changes (“mutations”) in genes located on the x chromosome are considered x-linked.

x-linked recessive inheritance

most x-linked conditions are recessive. this means that in a person with two x chromosomes (most females), both copies of a gene (i.e., one on each x chromosome) must have a change or mutation whereas in a person with one x chromosome (most males), only one copy of a gene must have a mutation. a female with a mutation in one copy of a gene on the x chromosome is said to be a “carrier” for an x-linked condition. a male with a mutation in a gene on the x chromosome is typically affected with the condition. because females have two copies of the x chromosome and males have only one x chromosome, x-linked recessive diseases are more common among males than females. however, x-linked recessive diseases can occur in both males and females.

for x-linked recessive disorders, an unaffected carrier mother who has a mutation in a gene on the x chromosome can transmit either the x chromosome with this mutation or a “normal” x chromosome to her children. if the father is unaffected, none of her daughters will be affected and all of her daughters will be unaffected—since they will inherit at least one normal x chromosome from their father. however, each daughter will have a 50% chance of being an unaffected carrier like her mother and a 50% chance of both x chromosomes being normal.