GENESIS 1 11 24 Then God said Let

GENESIS 1: 11, 24 Then God said, “Let the land produce vegetation: seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds. • So God created the great creatures of the sea and every living and moving thing with which the water teems, according to their kinds, and every winged bird according to its kind, and God saw that it was good. • And God said, “Let the land produce living creatures according to their kinds: livestock, creatures that move along the ground, and wild animals, each according to its kind, and it was so.

INTRO. TO GENETICS • • • Genesis 1: 11, 24 Heredity- biological inheritance; brings differences between species Genetics- branch of biology that studies heredity Early ideas about heredity Blended traits Gregor Mendel: Monk, 1850’s did work leading to genetics Self-pollination: Pollen produced by the plant, fertilizes the egg of the same plant. Offspring inherit all characteristics from one plant Cross-pollination: Pollen produced by the plant, fertilizes the egg of another plant. Offspring inherit characteristics of both plants. Purebred: Offspring having only one form of a trait w/ea. Gen. Traits: Characteristics that can be passed on to offspring

GENES AND DOMINANCE • • Hybrids: Organisms produced by crossing parents with differing characteristics. Mendel crossed Tall/short & Yellow/green. Results? ? ? ? ? Genes: Factors that control traits; segment of DNA that codes for a particular protein. Alleles: Different forms of a gene for a specific trait. Ex. Tall/short Principle of Dominance Dominant alleles- are present with contrasting recessive alleles. Recessive alleles- are not observed in the presence of dominant alleles Although dominance is seen in many traits, it doesn’t apply to all genes

SEGREGATION • • What happened to the recessive characteristics? P generation-parental plants F-1 generation- first generation of plants produces by crosspollinating them among themselves. F-2 generation- F-1 plants crossed with themselves THE F-1 CROSS: The recessive characters had not disappeared in all plants. Why did the recessive alleles disappear in the F 1 generation and reappear in the F 2? SEGREGATION: (separation) separation of alleles during gamete formation.

INDEPENDENT ASSORTMENT • • • Does the segregation of one pair of alleles affect the segregation of another pair of alleles? (Must a round seed by yellow? ) THE TWO FACTOR CROSS: RRYY or rryy Fig. 9 -9: remember we’re looking at kind of seeds produced What is the phenotype of the F 1 generation? We need the seeds from the F 2 to test our theory Fig. 9 -10 What happens when we cross F 1? Do RY and ry show up? If genes aren’t connected they segregate independently Independent Assortment: Genes segregate independently Fig. 9 -11: Rr. Yy w/ Rr. Yy

MENDEL’S SUMMARY • The factors that control heredity are individual units know as genes. In organisms that reproduce sexually, genes are inherited from each parent. • In cases in which two or more forms of the gene for a single trait exist, some forms of the gene may be dominant and others may be recessive. • The two forms of each gene are segregated during the formation of reproductive cells. • The genes for different traits may assort independently of one another.