The "scissors" of the molecular biology are: DNA Restriction enzymes.
A restriction enzyme is a protein capable of cleaving a DNA fragment at a characteristic nucleotide sequence called a restriction site. Each restriction enzyme thus recognizes a specific site. Several hundred restriction enzymes are currently known.
Naturally present in a large number of species of bacteria, these enzymes have become important tools in genetic engineering.
The "glue" of the molecular biology are: DNA ligase
In molecular biology, DNA ligases are ligase-class enzymes that catalyze the formation of a phosphodiester bond between two segments of DNA. DNA ligases are involved in several essential cellular processes of DNA metabolism: in DNA replication, suture of Okazaki fragments, and in DNA repair and homologous recombination.
The use of these tools in molecular biology: Cloning
Molecular cloning is one of the bases of genetic engineering. It consists of inserting a DNA fragment (called insert) in an appropriate vector such as a plasmid for example. The new plasmid thus created will then be introduced into a host cell, generally the Escherichia coli bacterium. This will then be selected and multiplied to obtain a large amount of the plasmid of interest. Cloning a gene involves inserting it into a plasmid. A clone will be the bacterial transformant that contains this particular plasmid. In this case we speak of clone because all the individuals of the bacterial colony are genetically identical. Molecular cloning is thus different from reproductive cloning (creating an individual genetically identical to another but of a different age) or therapeutic cloning (making tissues from stem cells to perform transplants compatible with the recipient).
Molecular cloning requires restriction enzymes capable of cleaving the DNA, and DNA ligase capable of re-gluing the DNA fragments. Ligase was isolated for the first time from T4 bacteriophage. This enzyme is involved in the repair and replication of DNA. It can bind DNA fragments with compatible sticky ends. At higher concentration, this enzyme is also able to bind two ends of DNA as shown here. T4 DNA ligase works using ATP and Mg ++. It has an activity optimum of 16 ° C, but remains active at room temperature.
Answer:
Option-C
Explanation:
A pulse-chase experiment which is used to study the cellular process taking place in the cells. This uses the labelled molecule which is incorporated into the cellular pathway and then the unlabeled molecules are used over time to determine how much time is required by the unlabeled molecule to replace the labelled molecule.
In the given question, the pancreatic cell which secretes the digestive enzyme known as the acinar cell is labelled with the leucine and then used unlabeled leucine.
When observed after three hours, the black spots will appear on the exterior of the cell as the protein has been synthesised by the ER and now has been secreted from the cell.
Thus, Option-C is the correct answer.
Answer:
Explanation:
Disadvantages of internal fertilization are that there are lesser number of offspring produced at a given time because it is sometimes difficult for the male and female to come into intimate contact. Additionally, the risk of sexually transmitted diseases also increases.
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Answer:
The correct answer is :
Independent Variable: side of the shower with lemon juice
Dependent Variable: cleanliness of shower
Control: spray of water
Conclusion: lemonade juice have no effect on slime
Explanation:
Independent variable in any experiment is the variable that is changed or manipulated as here side of the shower that is sprayed with lemonade juice is manipulated to see if there is any effect on the cleanliness of shower.
Dependent variable is the variable that is observed or measured to check if manipulated variable or independent variable have any effect on it, like the cleanliness is measured to check if lemonade juice clean the slime of the side or not.
The control is something that remains the same to check the condition or effect that is not changed or can be compared to it. Water spray is control in this case.
The conclusion of this experiment is that there is no effect of lemonade juice on the cleanliness of slime present in the shower
