Premium Essay

Dna Reproductive Process

In: Science

Submitted By CohnerBoner
Words 1062
Pages 5
Jacob Cohn
Mr. Lander
Period 4
When the two strands of DNA double helix are separated, each can serve as a template for the replication of a new complementary strand, producing two daughter molecules each of which contains two DNA strands with an antiparallel orientation. The enzymes involved in DNA replication process are template-directed polymerases that can synthesize the complementary sequence of each strand with extraordinary fidelity. This complex leads to the local denaturation and unwinding of an adjacent A + T rich region of DNA. The interaction of proteins with the origin is what defines the start site of replication and provides a short region of single stranded DNA essential to initiation of synthesis of the nascent DNA strand. Then helicase binds and allows for processive unwinding of double stranded DNA into single stranded DNA. As helicase unwinds the DNA, DNA single stranded protiens bind and stabilize the single stranded DNA. The polymerase III holoenzyme binds to template DNA as a part of a multi protein complex that consists of several polymerase accessory factors. DNA polymerase synthesizes DNA only in the 5 ' to 3 ' direction and only one of the several different types of polymerases is involved at the replication fork. As the DNA strands are anti parallel, the DNA polymerase functions asymmetrically. On the leading (forward) strand, the DNA is synthesized continuously. On the lagging strand (retro strand) the DNA is synthesized in short (1-5 kb) fragments. These DNA fragments are called as okazaki fragments. The proof function identifies copying errors and corrects them. Polymerase III is an enzyme with high processivity and catalysing capacity than others. The initiation of DNA synthesis requires priming by a short length of RNA about 10-200 nucleotides long. This priming process involves the nucleophilic attack by the 3' -OH…...

Similar Documents

Premium Essay

Dna Technology

...DNA Technology DNA research has come a long way since Friedrich Miescher first isolated it in 1869 and the discovery of DNA’s double helix structure by James Watson and Francis Crick in 1953. Surely they would have never imagined what scientists can do with human DNA today. Cloning, gene therapy, stem cell research, and genetically modified foods all began with the discovery of DNA and probably would have been unimaginable in anyone’s eyes in the 1800’s. But scientist’s today are manipulating genes and DNA in an effort to prevent disease, cure disease, and feed the world. History was made on July 5, 1996 when Dolly the sheep was born. She was the first mammal to be cloned from adult DNA. By splitting two-cell embryos apart, scientists were able to produce two genetically identical organisms. Cloning is a process of making genetically identical organisms through non-sexual means. There are three types of cloning, DNA cloning, reproductive cloning, and therapeutic cloning. DNA (or molecular) cloning consists of removing a small piece of the DNA strand and uniting it with a plasmid which reproduces itself to create multiple copies of the same DNA code. The copied DNA can then be grown in a suitable host cell where the recombinant vector can then be reproduced along with the host cell DNA. DNA cloning is typically used in biological experiments and technological applications where large scale protein production is needed. (NRC, 2002) Reproductive......

Words: 640 - Pages: 3

Free Essay

Attack of the Clones

...perfect example of such attempts. In nature, cloning is the process by which genetically identical organisms are produced by way of asexual reproduction. With some success, scientists have been working on ways to reproduce this phenomenon through biotechnology, in a laboratory setting. In biotechnology, cloning refers to the process used to create copies of DNA, cells, or entire organisms. Each of these forms of cloning will be described in this paper, which will then explore the issues surrounding cloning from biological, technological and public health standpoints. Molecular cloning, or DNA cloning, is the process of making multiple copies of an isolated sequence of DNA fragments (Strachan & Read, 1999). This form of cloning is most often used in biological research, but is also used in more practical applications such as genetic profiling and protein production. In practice, techniques such as this are often  used producing vaccines and researching cures to common ailments. Molecular cloning isolates a desired segment of a DNA and links this fragment to a primary DNA sequence that is capable of replicating itself and the fragment DNA linked to it. Once this new DNA sequence has been formed, it is then inserted into a cell which will make identical genetic copies of the new DNA sequence (Strachan & Read, 1999). Recently researchers at the University of California, San Diego (UCSD) have begun to......

Words: 2102 - Pages: 9

Premium Essay

Stem Cell Research Paper

...debate over the ethics of cloning began. In particular, reproductive cloning was widely discussed because it could possibly be accomplished through somatic cell nuclear transfer to clone entire humans (“Cloning Fact Sheet”). For medical, social, religious, and political reasons, there are both proponents and opponents of reproductive human cloning and its ethics. Currently, the best way to deal with reproductive cloning is to ban its use because there are many negative consequences that could arise from using cloning technology. There are two different types of human cloning: therapeutic cloning and reproductive cloning. The goal of the former is to obtain stem cells from embryos that can be used to study the growth of the human body and to find possible cures and treatments for various diseases (“Cloning Fact Sheet”). The purpose of the latter, on the other hand, is to create a whole human being through cloning. Specifically, reproductive cloning is done using somatic cell nuclear transfer and can theoretically produce a human that has the same exact nuclear DNA as another individual. Currently, though, this technology has only been used to clone animals and has not yet been successful in cloning humans (“Cloning Fact Sheet”). The process constituting somatic cell nuclear transfer begins with the extraction of nuclear genetic material from the cell of an adult donor. Then an egg is deprived of its nucleus, and the DNA taken from the donor cell is placed into the egg.......

Words: 1407 - Pages: 6

Free Essay

Newbury Local Conflct

...2.2.1- Outline the differences between reproductive and non-reproductive cloning Reproductive Cloning: production of offspring which are genetically identical to the mother or the other offspring Non- Reproductive Cloning: Use of stem cells in order to generate replacement cells, tissues and organs which may be used to treat particular diseases 2.2.2- Describe the production of natural clones in plants using the example of vegetative propagation in elm trees Vegetative Propagation: The production of structures in an organism that can grow into new individual organisms These offspring contain the same genetic information as the parent so they are clones of the parent. In Elm Trees: The elm tree is adapted to reproduce asexually following damage to the parent plant. This happens by separation of some body part of the plant body and its development into a new plant. In an elm tree this occurs by: Root Suckers/ Basal Sprouts are removed from a tree in autumn and are grown in a nursery bed. They appear within 2 months of destruction. The suckers grow from meristem tissue in the trunk which is close to the ground (area of least damage) 2.2.3 – Describe the production of artificial clones of plants from tissue culture Tissue Culture: Large scale cloning 1- A small piece of tissue from the plant is taken to be cloned. It is called an explant 2- In aseptic condition, the explant is placed on a nutrient growth medium......

Words: 1859 - Pages: 8

Premium Essay

What Is Cloning

...What is Cloning? Clones are organisms that are exact genetic copies. Every single bit of their DNA is identical. Clones can happen naturally—identical twins are just one of many examples. Or they can be made in the lab. Below, find out how natural identical twins are similar to and different from clones made through modern cloning technologies. How Is Cloning Done? Many people first heard of cloning when Dolly the Sheep showed up on the scene in 1997. Artificial cloning technologies have been around for much longer than Dolly, though. There are two ways to make an exact genetic copy of an organism in a lab: artificial embryo twinning and somatic cell nuclear transfer. 1. Artificial Embryo Twinning Artificial embryo twinning is a relatively low-tech way to make clones. As the name suggests, this technique mimics the natural process that creates identical twins. In nature, twins form very early in development when the embryo splits in two. Twinning happens in the first days after egg and sperm join, while the embryo is made of just a small number of unspecialized cells. Each half of the embryo continues dividing on its own, ultimately developing into separate, complete individuals. Since they developed from the same fertilized egg, the resulting individuals are genetically identical. Artificial embryo twinning uses the same approach, but it is carried out in a Petri dish instead of inside the mother. A very early embryo is separated into individual cells, which are......

Words: 8659 - Pages: 35

Premium Essay


...complex mixtures of DNA. Cloned genes also make it easier to study the proteins they encode. Because the genetic code of bacteria is identical to that of eukaryotes, a cloned animal or plant gene that has been introduced into a bacterium can often direct the bacterium to produce its protein product, which can then be purified and used for biochemical experimentation. Cloned genes can also be used for DNA sequencing, which is the determination of the precise order of all the base pairs in the gene. All of these applications require many copies of the DNA molecule that is being studied. Gene cloning also enables scientists to manipulate and study genes in isolation from the organism they came from. This allows researchers to conduct many experiments that would be impossible without cloned genes. For research on humans, this is clearly a major advantage, as direct experimentation on humans has many technical, financial, and ethical limitations. Importance for Medicine and Industry The ability to clone a gene is not only valuable for conducting biological research. Many important pharmaceutical drugs and industrial enzymes are produced from cloned genes. For example, insulin, clotting factors, human growth hormone, cytokines (cell growth stimulants), and several anticancer drugs in use are produced from cloned genes. Before the advent of gene cloning, these proteins had to be purified from their natural tissue sources, a difficult, expensive, and inefficient process. Using......

Words: 5354 - Pages: 22

Premium Essay


...relative reproductive success of individuals. Genome Natural selection – Genetic change or changes in the frequencies of certain traits in populations due to differential reproductive success between individuals. Reproductive success – The number of offspring an individual produces and rears to reproductive age and individual’s genetic contribution to the next generation. Reproductively isolated Selective pressures – Forces in the environment that influence reproductive success in individuals. Taxonomy – A branch of science concerned with the rules of classifying organisms on the basis of evolutionary relationship – systemchlel Transmutation – A change of one species to another – Macro evolution – Speciation Uniformitarianism Chapter 3. The Biological Basis of Life Amino acids – Small molecules that are the components of proteins. Autosomes – any of the chromosomes excluding the two sex chromosomes Centromere – constricted portion of a chromosome. After replication, the 2 strands of a double-stranded chromosome are joined at the centromere. Chromosomes – Discrete structures composed of DNA protein found only in the nuclei of cells Clone – An organism that is genetically identical to another organism Codons – 3 nitrogenous bases found on the mRNA which compliments 3 bases on a tRNA carrying a specific amino acid. Complementary – refers to the fact that certain bases in DNA and RNA always bind together. Cytosine always pairs with Guanine and, in DNA,......

Words: 1620 - Pages: 7

Premium Essay


...conclusions. The feat, cited by science magazine as the breakthrough of 1997, also created uncertainty over the meaning of "cloning" - a term traditionally used by scientists to describe different processes for duplicating biological material. The most common form of cloning is called reproductive cloning. There are different types of cloning and cloning technologies that can be used for other purposes besides producing the genetic twin of another organism. A basic understanding of the three different types of cloning are : (1) recombinant DNA technology or DNA cloning, (2) reproductive cloning, and (3) therapeutic cloning. I learned a lot from this article something that I found was really interesting is this process called "somatic cell nuclear transfer". This process is where the scientist transfer genetic material from the nucleus of a donor adult cell to an egg whose nucleus, and then its genetic material, has been removed. The reconstructed egg containing the DNA from a donor cell must be treated with chemicals or electric current in order to stimulate cell division then placed inside the mother and continues with a normal birth. This changes my opinion on cloning cause I never knew the cloning process has already been done on animals before and seeing that we share 93% of the same genetic makeup of monkeys there is no telling the limitations of cloning. This article connects to my biology class because in class I learned that with cloning we could bring back our......

Words: 360 - Pages: 2

Free Essay

Heredity Is Defined as the Transmission of Genetic

...To Offspring Introduction Anatomy refers to the science dealing with the description and identification of the structure of organs, tissues and organisms. It studies the body parts structures and how they relate with each other; it enables us to understand the relationship between the bones, muscles, ligaments and tendons. On the other hand, Physiology is the science which studies the functions of tissues, cell, organisms and organs. Physiology combines both physics and chemistry in its explanations. Physiology therefore, refers to the study of how the body functions. The reproductive system of male organs is specialized for: the production, transportation and maintain the sperm (these are the male reproductive cells) and also included are the semen, which is the protective fluid. Another function for the male reproductive organs is to discharge the male reproductive cells into the female reproductive tract. They also secrete and produce male sex hormones. The female anatomical structure is more complicated than the males’. There are many distinct anatomical structures comprising both internal and external tracts of the female genitalia; corpus spongiosum and labia minora (vestibular), urethra, G-spot, Halban’s fascia and peri-urethral glans, cervix, anteria erogenous zone and pubococcygeus muscle. Cutaneous blood vessels, nipples, sweat and salivary glands are some of the many peripheral non-genital anatomic structures in the response of female sexuality. Analysis......

Words: 2167 - Pages: 9

Free Essay


...Snap! Sperm cell Sexual reproduction occurs when offspring result from the joining (fusion) of a male reproductive cell and a female reproductive cell. These special reproductive cells are called gametes and are made in the reproductive organs of organisms. In animals, male gametes are called sperm and female gametes are called ova (singular = ovum) or egg cells. Reproductive systems are designed to bring the male and female gametes together. The joining of sperm and egg cells is called fertilisation. This process mixes the genetic material from the nucleus of each parent together and results in the formation of a zygote. Human sperm cells surround an ovum. MEETING OUTSIDE … In some animals, especially those that live or breed in water such as fish and amphibians, fertilisation occurs outside the female's body. This is called external fertilisation. In this situation, the female releases her unfertilised eggs into the water to be fertilised by the male's sperm, which are also released into the water. MEETING INSIDE … In animals that live and breed on land, internal fertilisation occurs. This keeps the gametes inside the body so there is no chance of dehydration occurring. In this situation, sperm are introduced into the female by a process called copulation (or sexual intercourse). Some differences between internal and external fertilisation Sexual reproduction involves fusion of gametes. Page 184 Ova Like sperm, ova are produced by a special type of cell......

Words: 817 - Pages: 4

Free Essay

Social Thinking and Infuences

...from the different populations sometimes mate with each other, but all of the resulting eggs are sterile. Which of the following conditions is necessary for speciation to occur? D) Reproductive isolation At which point in the adaptation of a population is it clear that speciation has occurred? B) Gene pool changes establish reproductive barriers between two populations. Prezygotic barriers _____. B) Prevent fertilization of gametes from members of closely related species Three species of frogs, Rana pipiens, Rana clamitans, and Rana sylvatica, all mate in the same ponds, but they pair off correctly because they have different calls. This is a specific example of a _____ barrier, called _____. A) Prezygotic ... behavioral isolation Which of the following reproductive barriers actually prevents individuals of closely related species from copulating successfully? B) Mechanical isolation Two species of water lilies in the same pond do not interbreed because one blooms at night and the other during the day. The reproductive barrier between them is an example of _____. A) Hybrid breakdown B) Temporal isolation C) Ecological isolation D) Gametic isolation E) Mechanical isolation temporal isolation   Which of the following is an example of a postzygotic reproductive barrier? A) One species of flower grows in forested areas, another in meadows. B) Two pheasant species perform different courtship dances. C) One species of frog mates in......

Words: 3591 - Pages: 15

Premium Essay


...operate 24 hours a day. The emissions these factories produce are amongst some of the highest in the world and contribute significantly to the amount noxious gases that pollute the air. (Hayden and Shandra 582) Industry aside, there are many other ways technology has had a negative, ecological impact on the world. In the modern home, there are numerous high technology gadgets designed to make our lives easier and more pleasant. These gadgets range from the microwave to the electric kettle to refrigeration. One of the largest contributors to gases in the atmosphere are the gases produced by the combustion process used to produce energy. (Williams 36) In the United States alone, 83% of this energy comes from a combustion process. (Williams 36) The combustion process is an effective way to produce energy for a wide range sources. The negative aspect of the combustion process however, is the amount of harmful gases that it produces. These gases can have a devastating impact on the ozone layer and contribute to what is known as the "Greenhouse Effect". What this effect essentially does is add to the increase in the warm air that filters around the globe through air currents such as the Gulf Stream. (Kilian 366) Often referred to as a thermal balance, these warm air currents affect the climate and seasons. As a result, there can unseasonably warm winters or, cool summer periods. More devastatingly though, is the harmful effect the increased thermal balance has on the Poles.......

Words: 3416 - Pages: 14

Premium Essay

Human Cloning

...biotechnologies and a call for deeper reflection and closer regulation of its use or, alternatively, as a bleak prophecy of the inevitable outcomes of reproductive technologies along the lines of the deterministic approach. As we shall see, the novel, as all good literature, is irreducible to a simplistic moral lesson and opens new and less explored possibilities for understanding biotechnological cloning and its juridical counterpart, transnational legal homogenization. The year is A.F. 632, (After Henry Ford). Huxley introduces us into a world, which has been taken over by technology. And yet, it is a world quite similar to our own, it is governed neither by robots nor by Martians, but by scientists, who have consciously adopted the logic of modern technology to its fullest extent. Humans, not machines, are in control and technology does not undermine the free will of humans, but quite to the contrary empowers them, and places them in a position of controlling not only nature, but human development. 11 In this World State, socially desired behavior is ensured by a double process of genetic manipulation and postnatal conditioning, which takes place in a fertilization and education facility, the Central London Hatchery and Conditioning Centre. In the Hatchery humans are manufactured on mass scale in lab conditions using special reproductive techniques. Early in the book, the D.H.C. (Director of the Hatchery Centre) explains to the incoming students how the new institution......

Words: 2667 - Pages: 11

Premium Essay

400 Journal (Ap Psychology)

...participants are first studied by means of a cross-sectional design but are also followed and assessed for a period of time | followed and assessed for a period of time | nature | the influence of our inherited characteristics on our personality, physical growth, intellectual growth, and social interactions | inherited characteristics | nurture | the influence of the environment on personality, physical growth, and intellectual growth, and social interactions | the influence of the environment | genetics | the science of inherited traits | inherited traits | DNA (deoxyribonucleic acid) | special molecule that contains the genetic material of the organism | special molecule that contains | gene | section of DNA having the same arrangement of chemical elements | same arrangement of chemical elements | chromosome | tightly wound strand of genetic material or DNA | genetic material or DNA | dominant | referring to a gene that actively controls | the expression of a trait | recessive | referring to a gene that only influences the expression of a trait when paired with an identical gene | expression of a trait when paired with an identical gene | conception | the moment at which a female become pregnant | female become pregnant | ovum | the female sex cell, or egg | female sex cell | zygote | cell resulting from the uniting of the ovum and sperm | uniting ovum and sperm | monozygotic twins | identical twins formed......

Words: 2239 - Pages: 9

Premium Essay

Micro Evolutionary Biology Notes

...Microevolutionary Process Notes * 1) Natural selection works on individuals * 2) Individuals do not evolve, populations do * Insecticide application didn’t result in insecticide resistance: some insects carry trait of resistance in their genes * Processes in Microevolution -Mutation -Non-random mating -Genetic Drift -Natural Selection -Gene Flow * Hardy-Weinburg Theorem: Frequencies of alleles and genotypes are preserved from generation to generation in populations that are not evolving -p2 + 2pq + q2 = 1 * Hardy-Weinburg tells us that we will never get rid of bad genes and it’s used to figure how gene populations change over time * The Hardy-Weinberg theorem describes a pop’n that is not evolving. It has 5 assumptions: 1. Genetic Drift: This represents random changes in small gene pools due to sampling errors in propagation of alleles. The bottleneck effect and founder effect are prime examples of genetic drift. In either case the number of individuals in a population is drastically reduced distorting the original allelic frequencies. (H-W assumes large population) 2. Gene Flow: The movement of alleles into and out of a gene pool. Migration of an organism into different areas can cause the allelic frequencies of that population to increase. Most populations are not isolated, which is contrary to the Hardy-Weinberg Theorem. (H-W assumes the population isolated from others) 3. Mutations: These changes in the genome of an organism......

Words: 2331 - Pages: 10