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Posted by on May 15, 2013 in Genetics |

What Is DNA?

 If you have any genetics questions, head for the Ninja Mutant Mastos (genetics) forum and ask away. 

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We all know that dogs only give birth to little dogs, elephants to elephants, chimpanzees to chimpanzees and on and on for every type of living being on Earth. But how can this be?

The answer lies in a molecule called deoxyribonucleic acid or “D.N.A.”, which contains the biological instructions that make each species on Earth unique. DNA, along with the instructions it contains, is passed from adult organisms to their offspring during reproduction.

What does DNA do?

DNA contains the instructions needed for an organism to develop, survive and reproduce.

To carry out these functions, DNA sequences must be converted into messages that can be used to produce proteins, which are the complex molecules that do most of the work in our bodies.

Where is DNA found?

DNA is found inside a special area of the cell called the nucleus. Because the cell is very small, and because organisms have many DNA molecules per cell, each DNA molecule must be tightly packaged. This packaged form of the DNA is called a chromosome. During DNA replication, DNA unwinds so it can be copied. At other times in the cell cycle, DNA also unwinds so that its instructions can be used to make proteins and for other biological processes. But during cell division, DNA is in its compact chromosome form to enable transfer to new cells.

Researchers refer to DNA found in the cell's nucleus as nuclear DNA. An organism's complete set of nuclear DNA is called its genome. Besides the DNA located in the nucleus, humans and other complex organisms also have a small amount of DNA in cell structures known as mitochondria. Mitochondria generate the energy the cell needs to function properly. In sexual reproduction, organisms inherit half of their nuclear DNA from the male parent and half from the female parent. However, organisms inherit all of their mitochondrial DNA from the female parent. This occurs because only egg cells, and not sperm cells, keep their mitochondria during fertilization.

What is DNA made of?

DNA is made of chemical building blocks called nucleotides. These building blocks are made of three, separate parts: a phosphate group, a sugar group and one of four types of nitrogen bases. To form a strand of DNA, nucleotides are linked into chains, with the phosphate and sugar groups alternating.
The four types of nitrogen bases found in nucleotides are: adenine (A), , thymine (T), guanine (G) and cytosine (C). The order, or sequence, of these bases determines what biological instructions are contained in a strand of DNA. For example, the sequence ATCGTT might instruct for blue eyes, while ATCGCT might instruct for brown.

Each DNA sequence that contains instructions to make a protein is known as a gene. The size of a gene may vary greatly, ranging from about 1,000 bases to 1 million bases in humans. The complete DNA instruction book, or genome, for a human contains about 3 billion bases and about 20,000 genes on 23 pairs of chromosomes.

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Posted by on May 15, 2013 in Genetics |

18 Things You Should Know About Genetics

 If you have any genetics questions, head for the Ninja Mutant Mastos (genetics) forum and ask away. 

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18 Things You Should Know About Genetics is an animated film that presents fundamental background information about genetics, as well as offering some quirky but interesting facts about DNA, genes and genetics. It was created to be an upbeat, fun educational short film to initiate and draw interest to this sometimes daunting and seemingly complex subject matter.

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Posted by on May 14, 2013 in Genetics |

Mutations

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Disregard its content, if any, as it only contains raw reference material for the future post.

 If you have any genetics questions, head for the Ninja Mutant Mastos (genetics) forum and ask away. 

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Posted by on May 14, 2013 in Genetics |

Chromosomes

 If you have any genetics questions, head for the Ninja Mutant Mastos (genetics) forum and ask away. 

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What is a chromosome?

To solve problems that explain and predict traits and variations, we first have to understand cells. All living organisms are composed of cells. Cells work like little factories doing all the jobs inside your body that are needed to keep your body functioning. Your body is made up of many different kinds of cells such as skin cells, muscle cells, and nerve cells. Some cells look like squashed bricks, some look like doughnuts, and many have irregular shapes. However, every cell, no matter what its job, has the same basic parts.

All human cells have an outer border that is the boundary of the cell called the cell membrane. A liquid material called cytoplasm is inside the cell membrane, and there is a large structure suspended in the cytoplasm called the nucleus. The nucleus is the part of a cell that contains the genetic information. The nucleus is surrounded by a nuclear membrane that, like the cell membrane, makes a boundary around the nucleus.

Now let's explore chromosomes.  Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid, or “DNA”. Passed from parents to offspring, DNA contains the specific instructions that make each type of living creature unique. The term chromosome comes from the Greek words for color (chroma) and body (soma). Scientists gave this name to chromosomes because they are cell structures, or bodies, that are strongly stained by some colorful dyes used in research.

So what do chromosomes actually do?

The unique structure of chromosomes keeps DNA tightly wrapped around spool-like proteins, called histones. Without such packaging, DNA molecules would be too long to fit inside cells. For an organism to grow and function properly, cells must constantly divide to produce new cells to replace old, worn-out cells. During cell division, it is essential that DNA remains intact and evenly distributed among cells. Chromosomes are a key part of the process that ensures DNA is accurately copied and distributed in the vast majority of cell divisions.

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Posted by on May 14, 2013 in Genetics |

What Are Genes?

 If you have any genetics questions, head for the Ninja Mutant Mastos (genetics) forum and ask away. 

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Posted by on May 14, 2013 in Genetics |

Single Nucleotide Polymorphism (SNP)

 If you have any genetics questions, head for the Ninja Mutant Mastos (genetics) forum and ask away. 

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Want to understand what Snips are, so that you can unravel your 23and me results? Here's a Visualization of SNPs in the genome.

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