* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Mendel and meiosis
Survey
Document related concepts
Inbreeding avoidance wikipedia , lookup
Transgenerational epigenetic inheritance wikipedia , lookup
Biology and consumer behaviour wikipedia , lookup
Genetic engineering wikipedia , lookup
Epigenetics of human development wikipedia , lookup
Minimal genome wikipedia , lookup
Genomic imprinting wikipedia , lookup
Hardy–Weinberg principle wikipedia , lookup
History of genetic engineering wikipedia , lookup
Designer baby wikipedia , lookup
Dominance (genetics) wikipedia , lookup
Microevolution wikipedia , lookup
Transcript
Mendel and meiosis • Gregor Mendel an Austrian monk from the midnineteenth century, carried out studies of heredity,--the passing on characteristic from parents to the offspring. • Traits,--are the characteristic that are inherited. • Mendel was the first person to succeed in predicting how traits are passed from one generation to the next. Genetics and stuff • Genetics,--the branch of biology that studies heredity. • Gametes,--are the male and female sex cells • The male gamete forms in the pollen grain, which is produced the male sex organ. The female gamete forms into a female sex organ. • Fertilization, when a male gamete unites with a female gamete • Zygote,-- is a fertilized cell. Pollination • Pollination,--The transfer of pollen grains from a male reproductive organ to a female reproductive organ • In peas both organs are located in the flower. Mendel's Monohybrid crosses • Mendel crossed bred plants with other plant and he called the cross breeds Hybrids,--is an offspring of parents that have different forms. • Mendel’s first experiments are called monohybrids, mono means “one” and the two parent plants differed from each other by a single trait—height. The rule of unit factors • Genes exist in alternative forms. We call these different gene forms Alleles. • For example each of Mendel's pea plants had two alleles of the gene that determined its height. • An organism’s two alleles are located on different copies of a chromosome—one inherited from the female parent and one from the male parent. Dominance and Recessive • Dominance,--observed trait of an organism. • Recessive, trait of an organism that can be masked by the dominate form of a trait. Segregation • Law of segregation,--Mendelian principal explaining that because each plant has two different alleles, it can produce two different types of gametes. • During fertilization, male and female gametes randomly pair to produce four combinations of alleles. Genotype and phenotype and homozygous • Genotype,--is the combination of genes in an organism. • Phenotype,--is the outward appearance of an organism regardless of its genes. • an organism is Homozygous,-- for a trait if its two alleles are the same. Punnett squares • In 1905, Reginald Punnett, an English biologist, devised a shorthand way of finding the expected proportions of possible genotypes and offspring of a cross. This method is called a Punnett Square. Law of independent assortment • Law of independent assortment,-Mendelian principle stating that genes for different traits are inherited independently of each other. Probability • Punnett squares are good for showing all the possible combinations of gametes and the likelihood that each will occur.