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1 May LAW OF DOMINANCE: The law of dominance, states that recessive alleles, will always be masked or dominated, by dominant alleles. E.G. Mendel found that when pea plants with round seeds (RR) were crossed with pea plants with wrinkled seeds (rr), all of the seeds in the FI generation were found to be round (Rr), as the round allele was dominant, the wrinkled recessive. INDEPENDENT ASSORTMENT: LAW OF The law of independent assortment, relates closely to the law of segregation. It states, that the segregation of different genes carrying varied characteristics occurs independently during gamete formation. During gamete production, the normal of chromosomes is reduced to half the, due to meiotic division to produce gametes containing 23 chromosomes only. The normal human cell contains 46 chromosomes; half the number of chromosomes is derived maternally, e.g. from the female gamete (the egg cell) and the other half is derived paternally, e.g.from the male gamete (the sperm cell). During sexual reproduction, female and male gametes fuse together to produce a new organism/zygote. The law of independent assortment explains that different alleles and genes, are independently inherited during the meiosis of organisms that reproduce sexually. The independent assortment of chromosomes is a result of the independent segregation of chromosomes into separate gametes. Crossing over takes place where genes on each chromosome are rearranged. GREGOR MENDEL'S OBSERVED CHARACTERISTICS: form Characteristics of pea plants Gregor Mendel used in his inheritance experiments Pod Seeds round roundish wrinkled cotyledons ∞ yellow green Flower colour white violett-red form full constricted between. colour yellow green position of inflorences axial Stem terminal size Fun Fact: Due to his extensive research and experiments, Mendel won the Nobel Prize of Physiology and Medicine long short EXAMPLE OF MENDEL'S EXPERIMENTS: Mendel's first experiment was cross-pollination of two true- breeding organisms - true-breeding means that an organism always passes down specific phenotype traits - which were flowers with contrasting colours (white and purple). However, Mendel's most famed experiment was with pea plants, which is widely what he is known for. During his pea observations, he grew over 10,000 plants, and he did this because pea plants are hermaphroditic (have both male and female sex cells), and they usually self-pollinate and fertilise. Mendel cross-pollinated them with a paintbrush, a technique used today too.