dragon genetics showing how the manipulation of alleles changed the dragon phenotype
Punnett square showing the traits of the fruitfly
Genetics is the study of biological inheritance. The molecular basis for our genes is DNA. DNA is composed of a chain of nucleotides and our genetic information exists along the chain. Chromosomes are the genes arranged along the DNA chain.
genotype- the genes of an individual
phenotype-trait or characteristic affected by the genotype
allele-alternative forms of a gene having different locus on the same chromosome, occur in pairs
cross-A monohybrid cross is a genetic cross where only one gene/trait is being studied. A dihybrid cross is a cross where two traits/genes are under consideration.
dominant (allele)-the one that’s fully expressed; symbolized by a capital letter, often the first letter of the word for which it stands
recessive (allele)-the one that’s almost always completely masked; symbolized by the SAME letter, but lower case. If a person has 2 recessive genes, that phenotype is expressed.
During gametogenesis, the chromosome number is reduced. A chromosome has 46, a gamete 23. This occurs as a result of meiosis. A monohybrid is an individual that is heterozygous to one pair of alleles. The Punnett sqaure is a tool which helps determine the outcome of genotypes/phenotypes. The genotypic ratio is 1:2:1 and the phenotypic ratio 1:3:1.
Genetic inheritance is influenced by the arrangement of alleles during fertilization. During meiosis (reduction division) , each of the parent cells contribute 1/2 of their chromosomes utilized during fertilization. Dependent upon the genotypes of both parents, the offspring will have different but predictable chances of inheriting certain traits. The Punnett square is a diagram which simplifies the process of determining the percentages of inheriting certain traits.
The gametes carry genes that are dominant or recessive. Upon fertilization, the combination of the genotypes determines the phenotype of the offspring.
Alleles occur in pairs and normally an individual has 2 alleles for each trait. A person with 2 dominant alleles has a homozygous dominant genotype. A person with 2 recessive alleles has a homozygous recessive genotype. A person with one of each has a heterozygous genotype. The genotype refers to the genes, the phenotype to the trait or characteristic.
Genetic inheritance is important for myriad reasons, but especially for the study and ramifications of many genetic diseases and disorders. Genetic disorders can be autosomal dominant: an individual with the alleles AA or Aa will have the disorder, or autosomal recessive: an individual with the alleles aa will have the disorder. A person's genome can be modified. Gene therapies such as ex vivo gene therapy or in vivo gene therapy can treat different medical conditions.
Genetic material must be able to do 3 things: replicate so it can be transmitted to the next generation, store information, and undergo mutations that provide genetic variability.
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