* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Ch 3 Sec3
Genome evolution wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
History of genetic engineering wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
Quantitative trait locus wikipedia , lookup
Gene expression programming wikipedia , lookup
Ridge (biology) wikipedia , lookup
Gene expression profiling wikipedia , lookup
Skewed X-inactivation wikipedia , lookup
Minimal genome wikipedia , lookup
Biology and consumer behaviour wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Microevolution wikipedia , lookup
Designer baby wikipedia , lookup
Genomic imprinting wikipedia , lookup
Epigenetics of human development wikipedia , lookup
Polycomb Group Proteins and Cancer wikipedia , lookup
Y chromosome wikipedia , lookup
Genome (book) wikipedia , lookup
Neocentromere wikipedia , lookup
The Cell and Inheritance • In 1903, an American geneticist, named Walter Sutton studied the cells of grasshoppers. – Focused on the movement of chromosomes during the formation of sex cells – Discovered that grasshopper’s sex cells have half the number of chromosomes as their regular body cells. – One chromosome in each pair came from each parent. Idea • Sutton’s idea came to be known as the Chromosome Theory of Inheritance. – Genes are carried from parent to their offspring on chromosomes. Meiosis • How do sex cells end up with half the number of chromosomes as body cells? – Meiosis •Chromosome pairs separate •They are distributed into 2 different cells •The resulting sex cells only have half as many chromosomes. Meiosis • Before meiosis- every chromosome in the parent cell is copied • Meiosis I– chromosome pairs line up in the center – The pairs separate and move to opposite ends – 2 cells form, each with half the number of chromosomes, each chromosome still has 2 chromatids Meiosis cont. • Meiosis II– The chromosome with their 2 chromatids move to the center of the cell – Centromeres split and chromatids separate, single chromosome move to opposite ends of the cell • End of meiosis- 4 sex cells have been produced, each with only half the number of chromosome as the parent cell in the beginning Line up of Genes • The human body contains 23 chromosome pairs for a total of 46 chromosomes. • Chromosomes are made up of many genes, like beads on a string. • Those 23 pairs of chromosomes contains 20,000 to 25,000 genes – Each gene controls a trait. Genetic Principles 1. Traits are passed from one generation to the next 2. Traits are controlled by genes 3. Genes are inherited in pairs, 1 gene from each parent 4. Genes can be dominant or recessive 5. Dominant genes “hide” recessive genes 6. Some genes are neither dominant nor recessive; they show incomplete dominance