Finals

• Genetic mutation


  Change in the information contained in genetic material
• Genetic mutation


  • Change in the nucleotide/base sequence of DNA
  • Molecular change to the amino acids that make up DNA, responsible for coding for our genes
  • May occur due to errors in DNA replication or due to the impacts of chemicals or radiation to the DNA molecule
• An organism's DNA affects how it looks, how it behaves, its physiology — all aspects of its life. So a change in an organism's DNA can cause changes in all aspects of its life.
• Mutations can be beneficial, neutral, or harmful for the organism, but mutations do not "try" to supply what the organism "needs." Whether a particular mutation happens or not, it is unrelated to how useful that mutation would be.
• Mutations are responsible for the diversity we see between organisms, but they are also at the root of some diseases. They have vastly different consequences depending on the segment of DNA they affect and how they alter it.
• Mutations can be grouped according to

  • Their sizes
  • Phenotypic effects
  • The cause of occurrence
  • The type of cell in which they occur
• Germline mutations


  Hereditary mutations, alterations to the normal human DNA sequence that are passed down from parent to child and exist in almost every cell in the human body
• Somatic mutations


  Acquired mutations, mutations that a person was not born with, and they can arise at any point in a person's life
• Illnesses related to a combination of environmental factors and mutations in multiple genes include arthritis, Alzheimer's disease, cancer, diabetes, heart disease, high blood pressure, and obesity.
• Somatic mutations occur in body cells, may have little effect on the organism, and cannot be passed on to offspring. Germline mutations occur in gametes, can be transmitted to offspring, and every cell in the offspring will have the mutation.
• If a parent carries a gene mutation in their egg or sperm, it can pass to their child. These hereditary (or inherited) mutations are in almost every cell of the person's body throughout their life. Other mutations can happen on their own during a person's life, such as from damage from the sun's ultraviolet radiation or exposure to some types of chemicals, and these mutations are not passed from parents to their children.
• Causes of mutation

  • DNA fails to copy accurately
  • A change in one or more nucleotides of DNA
  • A change in many genes
  • Loss of one or more genes
  • Rearrangement of genes or whole chromosomes
• Most of the mutations that we think matter to evolution are "naturally-occurring."
• Mutagen


  External influence that causes mutation
• Mutant


  Organism with a mutation
• Types of mutation


  • Chromosomal mutations
  • Gene mutations
• Chromosomal mutation


  • An abnormal change in the entire structure of a chromosome or in the number of chromosomes an organism has
• Trisomy 21


  • Normal humans have 46 chromosomes, humans with Down Syndrome have 47
• Structural chromosomal abnormalities


  • Robertsonian translocation
  • Reciprocal translocation
• Robertsonian translocation


  A type of chromosome rearrangement involving the exchange between the proximal short arms of the acrocentric chromosomes 13, 14, 15, 21 and 22. The most common is between chromosomes 13 and 14.
• DNA


  The MASTER PLAN
• Reciprocal translocation


  A type of chromosome rearrangement involving the exchange of chromosome segments between two chromosomes that do not belong to the same pair of chromosomes.
• RNA


  The BLUEPRINT of the Master Plan
• Balanced structural rearrangements


  • Inversion
• Differences between DNA and RNA

  • DNA has a sugar deoxyribose
  • DNA has thymine(T)
  • DNA is double-stranded
  • RNA has a sugar ribose
  • RNA contains the base uracil (U)
  • RNA molecule is single-stranded
• Inversion


  Occurs when the segment between two breakpoints is inverted before rejoining the breaks
• DNA


  • It reproduces itself when a cell divides (Replication)
  • Transmits the genetic information needed to operate the cell
  • It supplied information to make up RNA, proteins, and enzymes
• Unbalanced structural rearrangements


  • Deletion
  • Inversion
  • Duplication
  • Nondisjunction
• Genes


  Sequences of nucleotide bases that code for polypeptides (proteins)
• Deletion


  Due to breakage, a piece of a chromosome is lost
• Proteins


  • Used to build cells and do much of the work inside cells
  • Made of amino acids linked together by peptide bonds
  • 20 different amino acids exist
• Duplication


  Occurs when a gene sequence is repeated
• There are 20 different amino acids that create different combinations for specific functions in the body
• DNA


  Found inside the nucleus
• Ring chromosome


  Two ends of the segment between breakpoints are joined to form a circular structure
• Proteins


  Made in the cytoplasm of cells by organelles called ribosomes
• Protein Synthesis


  1. DNA's code must be copied and taken to the cytosol

  2. DNA code must be read in the cytoplasm so amino acids can be assembled to make polypeptides (proteins)
• Nondisjunction


  Failure of chromosomes to separate during meiosis, causes gamete to have too many or too few chromosomes
• Protein Synthesis


  • Process in which cells make proteins
  • Central dogma of biology
• Gene mutation


  • A change that affects a DNA at the molecular level by changing the normal sequence of a nucleotide base pairs, causes the cell to produce abnormal proteins