11Dominant vs. RecessiveDominant alleles show in an organisms phenotype whenever present in its genotype.Recessive alleles show their effect in an organisms phenotype only when two are present in the genotype
12Principle of Segregation Each parent passes only one allele for a trait to its offspring
13Principle of Independent Assortment The alleles for a trait do not influence the alleles for another
14Predicting Genetic Outcomes Mendel used probability to make predictionsReginald C. Punnett developed the Punnett Square 50 years after Mendel’s work was publishedWhen the parent’s genotypes are known, a Punnett square is used to predict the possible offspring
15Impact over TimeOver long time periods, the environment impacts a species’ ability to survive
16Non Living InfluencesInclude: temperature, rainfall, fire, elevation, volcanic eruptions, periodic flooding and pollution
17Reasons for AdaptingAvailability for food, predators, and the number of species living in an area affect a species’ survivalImage From:
18Darwin and WallaceOver time environmental factors can change the genetics of a speciesNatural SelectionImage From:
19Selective Breeding Humans choose the desired traits in the offspring Breeders of animals and plants in today's world are looking to produce organisms that will possess desirable characteristics, such as high crop yields, resistance to disease, high growth rate and many other phenotypical characteristics that will benefit the organism and species in the long term.
20Erwin Chargaffshowed that in natural DNA the number of guanine units equals the number of cytosine units and the number of adenine units equals the number of thymine units.Chargaff's research would later help Watson and Crick to deduce the double helix structure of DNA.Image from:www.wikipedia24.pl
21Rosalind FranklinWorked with x-ray radiation to take the first pictures of DNADied of cancer most likely related to her work with X-raysImage From:www.britannica.com
22Structure of DNA James Watson and Francis Crick In 1962 James Watson (1928– ), Francis Crick (1916–2004), and Maurice Wilkins (1916–2004) jointly received the Nobel Prize in medicine or physiology for their determination in 1953 of the structure of deoxyribonucleic acid (DNA).Image From:
24DNA by the numbers Each cell has about 2 m of DNA. The average human has 75 trillion cells.The average human has enough DNA to go from the earth to the sun more than 400 times.DNA has a diameter of only m.The earth is 150 billion mor 93 million miles fromthe sun.If you unravel all the DNA in the chromosomes of one of your cells, it would stretch out 2 meters. If you did this to the DNA in all your cells, it would stretch from here to sun more than 400 hundred times!
25DNA is made of a long sequence of smaller units strung together DNA is made of a long sequence of smaller units strung together. There are four basic types of unit: A, T, G, and C. These letters represents the type of base each unit carries: adenine, thymine, guanine, and cytosine. The sequence of these bases encodes instructions.Some parts of your DNA are control centers for turning genes on and off, some parts have no function, and some parts have a function that we don't understand yet.Other parts of your DNA are genes that carry the instructions for making proteins — which are long chains of amino acids. These proteins help build an organism.
26Mutations Process in which DNA changes to form new alleles Cross eyed, downs syndrome, extra digits,Opposable ThumbSome are advantageous
27Types of MutationsSubstitution A substitution is a mutation that exchanges one base for another (i.e., a change in a single "chemical letter" such as switching an A to a G). Such a substitution could:For example, sickle cell anemiaSickle cell anemia is a genetic disease with severe symptoms, including pain and anemia. The disease is caused by a mutated version of the gene that helps make hemoglobin — a protein that carries oxygen in red blood cells.
28Insertion: Insertions are mutations in which extra base pairs are inserted into a new place in the DNA.Original: The fat cat ate the wee rat.Insertion: The fat cat xlw ate the wee rat
29DeletionDeletions are mutations in which a section of DNA is lost, or deleted.Muscular Dystrophy:
30How mutations occurDNA fails to copy accurately Most of the mutations that we think matter to evolution are "naturally-occurring." For example, when a cell divides, it makes a copy of its DNA — and sometimes the copy is not quite perfect. That small difference from the original DNA sequence is a mutation.
32External influences can create mutations Mutations can also be caused by exposure to specific chemicals or radiation. These agents cause the DNA to break down. This is not necessarily unnatural — even in the most isolated and pristine environments, DNA breaks down. Nevertheless, when the cell repairs the DNA, it might not do a perfect job of the repair. So the cell would end up with DNA slightly different than the original DNA and hence, a mutation