Dalmatians have genes for white fur and black spots, and toy poodles have genes that make them small with curly fur. You get the idea! Scientists are very busy studying genes. They want to know which proteins each gene makes and what those proteins do. They also want to know what illnesses are caused by genes that don't work right.
Genes that have been changed are called mutations. Researchers think that mutations may be partly to blame for lung problems, cancer, and many other illnesses. Other illnesses and health problems happen when there are missing genes or extra parts of genes or chromosomes.
Some of these gene problems can be inherited from a parent. For example, take the gene that helps the body make hemoglobin say: HEE-muh-glow-bin. Hemoglobin is an important protein needed for red blood cells to carry oxygen throughout the body. If parents pass on altered hemoglobin genes to their child, the child might only be able to make a type of hemoglobin that doesn't work properly.
This can cause a condition known as anemia say: uh-NEE-mee-uh , a condition in which a person has fewer healthy red blood cells. Sickle cell anemia is one kind of anemia that is passed on through genes from parents to children. Parents with a changed CF gene can pass it on to their kids. People who have CF often have trouble breathing because their bodies make a lot of mucus say: MYOO-kus — the slimy stuff that comes out of your nose when you're sick — that gets stuck in the lungs. People with CF need treatment throughout their lives to keep their lungs as healthy as possible.
Gene therapy is a new kind of medicine — so new that scientists are still doing experiments to see if it works. It uses the technology of genetic engineering to treat a disease caused by a gene that has changed in some way. One method being tested is replacing sick genes with healthy ones. Gene therapy trials — where the research is tested on people — and other research may lead to new ways to treat or even prevent many diseases.
Reviewed by: KidsHealth Medical Experts. Larger text size Large text size Regular text size. What Is a Gene? Nucleotides have three parts: A phosphate group, a sugar group and one of four types of nitrogen bases. A gene consists of a long combination of four different nucleotide bases, or chemicals. There are many possible combinations. Different combinations of the letters ACGT give people different characteristics. Genes carry the codes ACGT. Each person has thousands of genes. They are like a computer program, and they make the individual what they are.
A gene is a tiny section of a long DNA double helix molecule, which consists of a linear sequence of base pairs. A gene is any section along the DNA with instructions encoded that allow a cell to produce a specific product — usually a protein, such as an enzyme — that triggers one precise action. DNA is the chemical that appears in strands. This is what makes each person unique. DNA is made up of two long-paired strands spiraled into the famous double helix.
Each strand contains millions of chemical building blocks called bases. Genes decide almost everything about a living being. One or more genes can affect a specific trait.
Genes affect hundreds of internal and external factors, such as whether a person will get a particular color of eyes or what diseases they may develop. A gene is a basic unit of heredity in a living organism. Genes come from our parents. We may inherit our physical traits and the likelihood of getting certain diseases and conditions from a parent.
Genes contain the data needed to build and maintain cells and pass genetic information to offspring. Each cell contains two sets of chromosomes: One set comes from the mother and the other comes from the father. The male sperm and the female egg carry a single set of 23 chromosomes each, including 22 autosomes plus an X or Y sex chromosome.
A female inherits an X chromosome from each parent, but a male inherits an X chromosome from their mother and a Y chromosome from their father. It is the largest single research activity ever carried out in modern science.
It aims to determine the sequence of the chemical pairs that make up human DNA and to identify and map the 20, to 25, or so genes that make up the human genome. The goal was to sequence 3 billion letters, or base pairs, in the human genome, that make up the complete set of DNA in the human body.
By doing this, the scientists hoped to provide researchers with powerful tools, not only to understand the genetic factors in human disease, but also to open the door for new strategies for diagnosis, treatment, and prevention. The HGP was completed in , and all the data generated is available for free access on the internet.
Apart from humans, the HGP also looked at other organisms and animals, such as the fruit fly and E. Over three billion nucleotide combinations, or combinations of ACGT, have been found in the human genome, or the collection of genetic features that can make up the human body.
Mapping the human genome brings scientists closer to developing effective treatments for hundreds of diseases. The project has fueled the discovery of more than 1, disease genes. This has made it easier for researchers to find a gene that is suspected of causing an inherited disease in a matter of days. Before this research was carried out, it could have taken years to find the gene. Genetic tests can show an individual whether they have a genetic risk for a specific disease.
The results can help healthcare professionals diagnose conditions. The HGP is expected to speed up progress in medicine, but there is still much to learn, especially regarding how genes behave and how they can be used in treatment.
At least biotechnology-based products are currently in clinical trials. In , the HapMap, a catalog of common genetic variation or haplotypes in the human genome, was created.
This data has helped to speed up the search for the genes involved in common human diseases. In the body, DNA holds the instructions for building proteins, and these proteins are responsible for a number of functions in a cell.
When you inherit genes from your parents you get two versions of each gene, one from your mum and one from your dad. Some versions of genes are more dominant than others; if you get blue-eye genes from mum and brown-eye genes from dad you will have brown eyes because brown-eye genes are dominant. Why are you different from your brothers and sister? When they pass their genes on to you they only pass on one of these versions, and it is completely random which one it will be. For example if your mum has brown-eye and blue-eye genes she could pass the blue ones on to you and the brown ones on to your sibling.
How do genes affect your health? Your genes are the instruction manual that makes your body work. Sometimes, one or a few bases of the DNA in a gene can vary between people. This is called a variant. A variant means the gene has slightly different instructions to the usual version. Occasionally, this may causes the gene to give cells different instructions for making a protein, so the protein works differently.
Luckily most gene variants have no effect on health. But a few variants do affects proteins that do really important things in your body, and then you can become ill. Play our Gene Finder game to see if you can spot the variant genes. Geneti c conditions: Genetic conditions are diseases you develop when you inherit a variant in a gene from your parents.
As a result genetic conditions usually run in families. Scientists have identified over 10, genetic conditions. One genetic condition is called sickle cell anemia. People with this illness have a variant in the genes that contain instructions to make haemolglobin proteins. Hemoglobin helps your red blood cells carry oxygen around your body.
These sickle cell haemoglobin genes cause red blood cells to be the wrong shape, making it hard for them to carry oxygen around the body. Not all gene variants cause a genetic condition. Many variants seem to have no effects at all, others may increase your risk of developing a disease. Rarely, there are women who are particularly at risk of developing breast cancer, because they carry some gene variants.
This can save lives. How does your environment affect you? Your characteristics are affected by your environment as well as your genes. For example you may inherit genes from your parents that should make you tall, but if you have a poor diet growing up your growth could be stunted.
To try and understand how much effect your environment can have on you, scientists study identical twins. Identical twins have the same genes, so any differences in personality, health and ability are caused by differences in their environment. Play Troublesome Twin to discover just how much how much your environment can affect you. Why do scientists study genes? Scientists have made huge breakthroughs in genetic research over the last few years, learning more and more about our genes and how they make our bodies work.
Scientists examine our genes to work out family relationships, trace our ancestors, and find genes involved in illnesses. This gives them the tools to come up with better ways to keep us healthy.
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