Heridity.

• Dominant Gene


  Decides the appearance of an organism even in the presence of an alternative gene
• Phenotype


  Visible characteristic in an organism (e.g., tall or dwarf)
• Heredity


  The transmission of characters from the parents to their offspring
• Mendel used Pisum sativum (garden pea) for his experiments and selected seven contrasting characters
• Mendel's Laws of inheritance: 1) Law of segregation - genes of a character separate randomly at the time of gamete formation
• Homozygous


  Has two same copies of the same form of gene coding for a particular trait
• Recessive Gene


  Decides the appearance of an organism only in the presence of another identical gene
• Variation


  Differences in the characters among the individuals of a species
• First Filial Generation or F1 Generation is produced when two parents cross to produce progeny
• Monohybrid Cross

  Cross between two pea plants to study one pair of contrasting characters
• Heterozygous


  Contains two different copies of a gene coding for a particular trait
• Mendel's Laws of inheritance: 2) Law of Dominance - only one of the two dissimilar factors present in an organism is expressed
• Genotype


  Description of genes present in an organism represented by a pair of letters (e.g., TT, Tt, or tt)
• Gregor Johann Mendel is known as the Father of Genetics
• Gene


  A unit of DNA that controls a specific characteristic of an organism
• Dihybrid Cross


  Cross made between two plants to study two pairs of contrasting characters
• Second Filial Generation or F2 Generation is produced when the first-generation progeny cross among themselves
• The sex of the child in human beings is determined by the 23 pairs of chromosomes
• Law of Independent Assortment: One pair of contrasting characters is inherited independent of the other character. In a dihybrid cross, traits are inherited independently
• Mendel's experiments show that traits may be dominant or recessive based on the expression of contrasting forms
• The creation of variations in a species promotes survival by allowing some variants to survive drastic environmental changes
• Law of Dominance: Out of two dissimilar factors present in an organism, only one expresses itself and is known as the dominant factor. The character unable to express itself is termed as recessive
• Information about a man with blood group A marrying a woman with blood group O and their daughter having blood group O is not enough to determine which blood group trait is dominant
• Individuals separate randomly at the time of gamete formation, resulting in gametes containing only a single factor or gene of a character
• If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, trait B is likely to have arisen earlier
• Mendel's experiments show that traits are inherited independently as seen in dihybrid crosses
• Equal genetic contribution of male and female parents is ensured in the progeny through the process of meiosis during gamete formation
• It cannot be determined if the light eye color trait is dominant or recessive without knowing the nature of the variants or studying at least three generations
• Child can have blood group O regardless of the dominance of O, so no conclusion can be drawn about which trait is dominated
• The mother provides only X chromosomes, and the sex of the baby is determined by the type of male gamete (X or Y) that fuses with the X chromosome of the female
• Women have a perfect pair of chromosomes (XX) and men have a mismatched pair (XY)
• O is Dominant


  Child may have blood group O
• Black skin coat is dominant over white skin coat in dogs based on a project selecting specific genotypes
• Sexual reproduction introduces more viable variations than asexual reproduction, leading to faster evolution in sexually reproducing organisms
• A child who inherits X chromosome from the father will be a girl, and one who inherits Y chromosome will be a boy
• Genetic make-up of the tall parent in a Mendelian experiment can be depicted as TtWW
• Sex of the child is determined by the type of sex chromosome inherited from the father