Exer 2

• Gregor mendel proposed 2 laws:

  • independent segregation

  • independent assortment
• Genes exists in two or more alternative forms called alleles
• Gene pair refers to pair of alleles
• Combination of alleles in an individual is called a genotype
• Combination of any behavioral, biochemical, morphological manifestation is called a phenotype
• Specific gene location is called locus
• 2 identical alleles present = homozygous
• During zygotene, homologous chromosomes pair
• Law of independent segregation states that alleles of gene pair separate completely and cleanly from each other during MEIOSIS
• Law of independent assortment states that gene pairs completely separates and cleanly from each other and randomly combing during meiosis
• Monohybrid cross is between homozygous individuals different at one gene locus
• Dominant allele is what’s manifested in heterozygote
• Masked allele is the recessive allele
• Punnet square or checkerboard method is used to get the genotypic ratio
• Testcross is to determine the heterozygosity.
• Dihybrid cross is between 2 homozygous individuals at two gene loci
• Branching method is another way to get the genotype
• The key for branching is to take each gene independently
• Probability is defined as the chance that an event will occur
• 2 types of events:

  • mutually exclusive

  • independent events
• Mutually exclusive events are thise that can never take place at the same time
• Independent events are events that can occur simultaneously
• Combined probability is the sum of individuals of each events is called sum rule of probabilities
• Combined probability is the product of the individual probabilities of each group is called product rule of probabilities.
• Conditional probability is to determine the probability of an event in light of another
• Binomial probability is a special type of probability
• Different alleles are independent of each other in segregation and recombination patterns
• No gene acts by itself