lesson 4

• Gamete is a reproductive cell containing only half the genetic material necessary to form a complete organism (haploid).
• Allele is any one of two or more genes that may occur alternatively at a given site (locus) on a chromosome; a pair of alternative Mendelian characters.
• Character is any observable feature or trait of an organism, whether acquired or inherited.
• Genotype is the genetic constitution of an organism.
• Phenotype is all the observable characteristics of an organism that result from the interaction of its genotype with the environment.
• Punnett Square is a useful tool for predicting what the offspring will look like when mating plants or animals.
• Phenotypic Ratio is a quantitative relation between phenotypes showing the number of times the frequency of one phenotype correlates with another.
• Genotypic Ratio is the ratio depicting the different genotypes of the offspring from a test cross.
• Genetics is the study of heredity (expression of traits and how they are passed from generation to generation) in general and of genes in particular.
• Gregor Mendel's work established genetics as a scientific study.
• Mendelian Genetics was established by Gregor Mendel by experimenting on pea plants (pisum sativum) in 1865.
• A human has 20,000 to 25,000 genes, which is called a genome, determining traits influenced by factors at a cellular level.
• Protein Synthesis involves DNA replication (A=T, C=G), transcription (replace Thymine with Uracil), translation (make amino acid strands through codons), and synthesis (final product).
• Genes are segments of DNA that provide a coding for information about a person's inherited trait.
• RNA, or ribonucleic acid, is a single-stranded (one chain of nucleotides) and bases AUCG (adenine, uracil, cytosine, guanine).
• The Law of Dominance states that hybrid offspring will only inherit the dominant trait in the phenotype, while the recessive traits are suppressed, and the alleles that determine the trait are known as the dominant traits.
• Pedigrees are diagrams that depict the biological relationships between an organism and its ancestors, similar to a family tree, showing information about an inherited trait passed across generations.
• The Law of Independent Assortment states that a pair of traits segregate independently of another pair during gamete formation, giving different traits equal opportunity to occur together.
• The Law of Segregation states that during the production of gametes, two copies of each hereditary factor segregate so that offspring acquire one factor from each parent.
• Mendelian Genetics established basic patterns of inheritance and identified the following concepts: True breeding, Hybrids, Dominant alleles, Recessive alleles, Homozygous genotype, Heterozygous genotype, DNA.
• • True breeding - Self-fertilization leads to offspring identical to the parent (with the same traits). 
• Hybrids - Self-fertilization leads to offspring that are not identical to parents.
• Dominant alleles - Alleles that exerts its effect when present; represented by a capital letter.
• Recessive alleles - Alleles whose effects are masked or not expressed when a dominant allele is present; represented by a small letter.
• Homozygous genotype - The genetic makeup of the individual contains identical alleles
• Heterozygous genotype - The genetic makeup of the individual contains different alleles.
• • Monohybrid Cross

   ➢ A breeding experiment between two (2) heterozygous individuals showing contrasting traits of one character 
• • Dihybrid Cross 

  ➢ A breeding experiment between two (2) individuals showing contrasting traits of two (2) different characters (both individuals are heterozygous for the two characters)
• • Test-Cross

  ➢ A breeding experiment used to identify the unknown genotype of an individual by crossing it with a homozygous recessive individual
• • Back Cross

  ➢ A breeding experiment where a member of the F generation is crossed with its parent (from the P generation)
• • Reciprocal Cross 

  ➢The parallel to a regular breeding experiment where the genotypes of the parents are switched. 
• the P1 or Parental Generation is the set of individuals being mated.
• Monohybrid crosses require one homozygous dominant parent and one homozygous recessive parent.
• The F1 or Filial Generation is the resulting offspring of P1; it contains one allele per parent. This generation will only be heterozygous offspring.
• The F2 is the resulting offspring after selffertilization of F1
• Central Dogma is the relationships between nucleic acid and proteins as a flow of information. ​
• A cell’s rewrites a gene’s DNA sequence to a complementary RNA molecules. Transcription
• The information in RNA, is used to assemble a different class of molecules. : a protein ( just an interpreter translate one language into another. Translation