Embryo Screening. The embryo screening, also referred as PGD (preimplantation genetic diagnosis), is a procedure tested on an embryo to identify any unwanted diseases that is found in the genes of the embryo.
Embryo Screening Settling down and starting a family is what many couples have in mind. It's a life changing decision the many indivisual choose to endure, however, obstacles and complications have delayed couples from fulfilling their goal. Leaving the chances of pregnancy aside, couples try to prevent many issues that occur with their newborns - infectious and complicated diseases, deformities and abnormalities. In many cultures and races, it is customary, or even the norm, to marry close relatives. This scientifically has been proven to increase the chances of having your offspring inherit the diseases that have been in the past generations, such as diabetes, cancer, anemia and leukemia. [8] One type of solution that has been discovered is embryo screening and human genetic engineering. The embryo screening, also referred as PGD (preimplantation genetic diagnosis), is a procedure tested on an embryo to identify any unwanted diseases that is found in the genes of the embryo. This then enables the couples to be aware of the problems that they might be facing if they do get pregnant, and leaving their embryo untouched. After enlightening couples about the genetic diseases found in the genes, they have to whether to go through the PGD and modify the genes to contract the ones that contain the genetic information about the disease, abnormality, or deformity. "PGD involves
Ganetics, Inheritance and Cells.
Inheritance Cells New cells are needed for- . Growth- as an organism grows it needs more cells 2. Repair- cells become damaged due to wear and tear 3. Replacement- cells wear out and die so each cell has to be able to make copies of itself. The instructions for doing this are contained in the chromosomes within the nucleus of each cell Each characteristic has it's own set of instructions called a gene These are found in the chromosomes In humans each cell has 46 chromosomes (23 pairs one of each pair coming from each parent) Mitosis Mitosis In this process exact copies of each cell are made This process happens all the time and is used for growth, repair and asexual reproduction in which the offspring are identical to the parent Stages of mitosis . The cell makes copies of all the chromosomes 2. The cell then divides into 2 each having one set of chromosomes. Skin is an example of a tissue that needs to be constantly doing this Each cell then can only make copies of itself ie skin cells only make skin cells and muscle cells only make muscle cells After fertilisation of an egg by a sperm there is just 1 cell and this needs to develop into a complete organism that contains many different tissues and so many types of cell Stem cells This is possible because the early embryo contains stem cells and these cells have the capacity to turn into any type of
Asexual reproduction and cloning
Asexual reproduction. When organisms reproduce asexually, there is no fusion of sex cells. A part of the organism grows and somehow breaks away from the parent organism. The cells it contains were formed by mitosis, so contain exactly the same genes as the parent. A sexual reproduction produces offspring that are genetically identical to the parent, and genetically identical to each other. A sexual reproduction is common in plants. For example, flower bulbs grow and divide asexually each season to produce more bulbs. Asexual reproduction also occurs in some animals such as the Hydra, a small freshwater animal, which reproduces asexually by 'budding'. Artificial cloning Artificial cloning of animals is now commonplace in laboratories. The most famous example of animal cloning is Dolly the Sheep, born in the UK in 1996 using a technique called embryo transplanting. Here's how it was done: . An egg cell was removed from the ovary of an adult female sheep, and the nucleus removed. 2. Using micro-surgical techniques, the empty egg cell was fused with DNA extracted from an udder cell of a donor sheep 3. The fused cell now began to develop normally, using the donated DNA. 4. Before the dividing cells became specialised the embryo was implanted into the uterus of a foster-mother sheep. The result was Dolly, genetically identical to the donor sheep. Advantages of embryo
Protein Synthesis is the process whereby DNA (deoxyribonucleic acid) codes for the production of essential proteins
Protein Synthesis Protein Synthesis is the process whereby DNA (deoxyribonucleic acid) codes for the production of essential proteins, such as enzymes and hormones. Proteins are long chains of molecules called amino acids. Different proteins are made by using different sequences and varying numbers of amino acids. The smallest protein consists of fifty amino acids and the largest is about three thousand amino acids long. Protein synthesis occurs on ribosomes in the cytoplasm of a cell but is controlled by DNA located in the nucleus. Protein synthesis is a two-part process that involves a second type of nucleic acid along with DNA. This second type of nucleic acid is RNA, ribonucleic acid. RNA differs from DNA in three main respects. First, the sugar units in RNA are ribose as compared to DNA's deoxyribose. Because of this difference, RNA does not bind to the nucleotide base Thymine (T), instead, RNA contains the nucleotide base Uracil (U) in place of T. (RNA also contains the other three bases: Adenine (A), Cytosine (C) and Guanine (G). Secondly, RNA, unlike DNA is a single stranded molecule and is therefore not bonded to a complimentary base. The third difference between RNA and DNA is that there are three different types of RNA, mRNA (messenger RNA), tRNA (transfer RNA) and rRNA (ribosome RNA). mRNA carries the genetic code (instructions how to assemble the protein)
The structure of nucleic acid chains (or DNA).
W.Feltham THE STRUCTURE OF NUCLEIC ACID CHAINS (or DNA). Nucleotides are joined together in DNA and RNA by phosphate ester bonds between the phosphate component of one nucleotide and the sugar component of the next nucleotide. An ester bond is a bond which occurs between a Carbon atom and an Oxygen atom. More and more nucleotides can be added on by the same process of forming ester bonds until an immense chain is formed. But no matter how long a polynucleotide chain is, one end of the nucleic acid molecule always has a free -OH group on the sugar at the Carbon known as C3' (called the 3' end) and the other end of the molecule always has a phosphoric acid group at C5' (the 5' end). The Carbons get this name from a counting system illustrated in the next diagram. (Fig 1) Beginning from the "right-hand" side of the sugar, count the Carbons....1', 2', 3' (where the phosphate group of the next nucleotide in a series can be linked via a chemical bond), 4', 5' (where the phosphate group of the previous nucleotide is linked via a chemical bond). This "counting system" allows the strand of nucleic acid to be oriented: the 5' end of the molecule always ends with a phosphate and the 3' end of the strand always ends with a sugar. You may be wondering why we don't just call the 5' end the "top" of the DNA or RNA molecule and the 3' end the
Genetically modified crops - Do we know all the answers?
Genetically Modified Crops. Do we know all the answers? Genetic Modification is the method of obtaining individual genes, which are then copied and repositioned into another living organism to modify its genetic code and incorporating or removing particular characteristics into or from an organism.1 There are many viewpoints on the issue genetic modification, some scientifically based on environmental factors and potential economic growth, others concerning ethical, moral and social perspectives. Ever since the breakthrough of genetic modification, deliberation has surrounded all issues involving this controversial topic. Many organizations have published books, videos, and leaflets arguing their side of this debate. Advances in GM biotechnology, such as the incorporation of the gene which stops the Arctic Flounder from freezing, has been placed into the genetic sequence of strawberries to stop them shrivelling in the cold British weather2, these 'modifications' have led to many intrinsic and extrinsic moral issues arising from this "new" technology. Dr Robert Farley of the Monsanto Institute, USA3 believes that genetic modification of crops for human consumption is a much more efficient and effective way of creating more resilient wheat crops than traditional cross-pollination. This is because genetic modification is more specific in changing a particular gene,
Evolution, what, and any evidence is there?
Opening In this case study I will be writing about evolution and, what, if any evidence there is. I chose this topic of science because im interested in how our species came about and how it’s been changed from theory to theory, and how it’s still being challenged. This, I hope, will interest and reading group of KS4. This may or may not help them with there GCSEs and revision. After they have read my case study, I hope they will make up there own minds using the for and against evidence presented. I will also so show my own opinion at the end of the study along with a conclusion for for and against, I will also compare the sources that I present and evaluate them to see if they are backing up their claims. Arguments for. A general explanation of how scientists think it works. This is an opening and explanation of evolution from Wikipedia: http://en.wikipedia.org/wiki/Modern_evolutionary_synthesis#The_modern_synthesis “The modern evolutionary synthesis (also referred to as the new synthesis, the modern synthesis, the evolutionary synthesis and the neo-Darwinian synthesis) is a union of ideas from several biological specialties which forms a logical account of evolution. This synthesis has been accepted by nearly all working biologists.[1] The synthesis was produced over about a decade (1936–1947), and the development of population genetics (1918–1932) was the
Is Cloning Ethical?
Is Cloning Ethical? For the past few years the political and ethical argument for and against the process of cloning has been raging. So is cloning really unethical? Is it against human rights? Before we decide this we must first understand exactly what cloning is. Cloning can be done using a few different processes, which will be later mentioned. It is the creation of an embryo which is a genetically identical copy of another human (1). There are three main types of cloning. The first is known as Embryo Cloning. This is a technique, the same as the natural process of making identical twins or triplets, where cells are taken from a fertilised egg and encouraged to develop into twins or triplets with identical DNA (2). The second is known as Reproductive or Adult DNA Cloning. This method is used to produce an animal with identical DNA to an existing animal. DNA from an ovum is removed and is replaced by DNA from an adult animal cell. It is then implanted into the womb of a surrogate mother and develops into an animal. This kind of cloning is illegal in many countries as, based on studies performed on animals, it could cause genetic defects. It is considered by many to be unethical and dangerous, however Dr Severino Aninori claims to have used this procedure to initiate pregnancy (2) Biomedical Cloning, better known as Therapeutic cloning is the third process. In the
