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.
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Answer:</h2>
I believe the correct answer is D. React to stimuli from outside the body.
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Explanation:</h2>
Hormones are types of proteins that produce responses hand in hand with neurons but they are much slower and longer lasting. They can act on the same cells and in that instance they will be called autocrine hormones. Those that act on neighbouring cells are called paracrine hormones while those that act on far away cells are called endocrine hormones.
<h2>Further Explanation:</h2><h3>a. Initiate behavior and reproduction:</h3>
This is a function of hormone(s). Hormones such as testosterone can initiate both behavior of an organism and also stimulate reproduction. Testosterone causes maturation of sex features and sperms in males to initiate reproduction. Other hormones with such functions include: Estrogen and adrenaline.
<h3>b. Coordinate the production and use of energy:</h3>
Some hormones conduct this function by regulation metabolism in the body. These include: Insulin in intake of glucose for energy and glucagon in maintaining blood glucose levels. Corticosterone also responds in stress to maintain energy.
<h3>c. Maintain nutrition and metabolism:</h3>
Nutrition can be maintained by hormones such as ghrelin that stimulates appetite, insulin in intake of glucose, leptin and glucagon.
<h3>d. React to stimuli from outside the body</h3>
This is not a function of a hormone but rather the function of a neuron. Neurons have specific structures called denrites that recieve signals/stimuli from outside the body then convert them to nerve impulses that are transmitted to the brain which produces another impulse to be taken to a specific site to produce a desired response.
Level: High Schoo;
20kg piece of pure gold, i think........
1. A , 2. D, 3. A , 4.C , 5. B , 6.A
