3Gregor Mendel Austrian Monk crossed some pea plants Laws of ____________There are alternative forms of genes, the units determining heritable characteristics. This is now known as an ____________An organism inherits one allele from each parent.
4SegregationA sperm or egg carries only one allele for each characteristic which pair upon fertilization.When the alleles are different, one is fully expressed and the other is masked, now known as ____________ and recessive genes.
5Genes and DominanceDominance - the ability of one allele to express its ____________ at the expense of an alternate allele;Generally the dominant allele will make a gene product that the recessive can not; therefore the dominant allele will ____________ itself whenever it is present
7Lets Practice:What do you get for F1 when your P generation is Homozygous dominant Yellow and green?What if you cross two of the offspring from that cross? What is the F2 generation?What if I said to cross a Tall with a Tall? What are the possible outcomes?
8Test CrossWhen you are not sure of the genotype of the dominant phenotype you do a test cross
9More Practice…What if I wanted to know if a flower was likely to be tall/ short and purple/ white?How would I do that?
10Dihybrid CrossIn any case where the parents are heterozygous for both traits (AaBb x AaBb) you will get a 9:3:3:1 ratio
11Independent Assortment This law states that allele pairs separate independently during the formation of ____________ Therefore, traits are transmitted to offspring independently of one another.
12Dihybrid CrossA cross (or mating) between two organisms where two genes are studied is called a DIHYBRID cross.The genes are located on separate chromosomes, so the traits themselves are unrelated.BB = blackBb = blackbb = whiteLL = short hairLl = short hairll = long hair
14Ggbb ____________________ ggBB ________________________ Also in rabbits, black eyes are dominant to red eyes. These letters represent the genotypes of the rabbits:GG = gray hair Gg = gray hair gg = white hairBB = black eyes Bb = black eyes bb = red eyes1. What are the phenotypes (descriptions) of rabbits that have the following genotypes:Ggbb ____________________ ggBB ________________________ggbb ____________________ GgBb _________________________
15A male rabbit with the genotype GGbb is crossed with a female rabbit with the genotype ggBb The square is set up below. Fill it out and determine the phenotypes and proportions in the offspring.How many out of 16 have grey fur and black eyes? ________How many out of 16 have grey fur and red eyes? ________How many out of 16 have white fur and black eyes? ________How many out of 16 have white fur and red eyes?
16Incomplete DominanceWhen there is no dominant or recessive, the heterozygous condition results in a "blending" of the two traits. Example: Snapdragons can be red, white, or pink (heterozygous)neither allele is dominant, red x white = pink
18CodominanceBoth are expressed in some way, red x white = white/red spotsUse all capital letters - Red (RR) x White (WW) = Red and white (RW) The old way still works, though.
19Sex linked TraitsThe genes for these traits are on the _____ chromosomebecause boys only receive one X chromosome they are more likely to inherit disorders passed to them from their ____________ who would be a carrier.Hemophilia and Colorblindness are sex linked traits, the punnet square below shows how a woman who is a carrier passes the trait to her son, but not her daughters.
22Muliple Allele TraitsTraits that are controlled by more than two alleles. Blood type in humans is controlled by three alleles: A, B, and OBlood can only be transferred to a body of a person who's immune system will "recognize" the blood. A and B are antigens on the blood that will be recognized. If the antigen is unfamiliar to the body, your body will attack and destroy the transfused blood as if it were a hostile invader (which can cause death).
23O is like a blank, it has no antigens O is like a blank, it has no antigens. O is called the universal donor because a person can receive a transfusion from O blood without having an immune responseAB is the universal acceptor, because a person with AB blood has both the A and B antigens already in the body, A and B blood can be transfused to the person (as well as O) and the body will recognize it and not attack.
25Environmentally Influenced Traits Siamese cats have dark ears and feet due to the temperature. Height in humans is influenced by the environment (diet)Traits are influenced by the environment. Pattern baldness affects men because testosterone activates the genes.THE ENVIRONMENT EFFECTS THE EXPRESSION OF GENES!!!!!!