PPT-13.2 Fertilization and meiosis alternate in sexual life cycle

Samantha Bonilla Vocabulary Karyotype Somatic cell Life cycle Homologous chromosome S ex chromosome Autosome Diploid cell Haploid cell. Objectives of lecture. Know possible origin of plants. Understand Alternation of generations concept. Green algae as ancestors of land plants. Green algae as ancestors. Green algae are considered to be ancestors of land plants. . Fertilization . – Union of 2 parent cells.. Sperm and egg cells called . gametes. .. Product of egg . +. sperm = fertilized egg = . zygote. .. . Embryo. = early stages of an organism’s development; from first cell division to end of 8. Mendelian inheritance has its physical basis in the behavior of chromosomes. You Must Know. How the chromosome theory of inheritance connects the physical movement of chromosomes in meiosis to Mendel’s laws of inheritance. Sexual Life Cycles. modes of reproduction. diploid/haploid and meiosis. meiosis I and meiosis II phases. key differences between mitosis and meiosis. variation in position of meiosis in life cycles. why sex?. Image from about.com . meiosis_metaphase_1.jpg. . Mutations. (changes in an organism’s DNA) are the . original. . source of . all. genetic variation. Mutations create different versions of genes called . Variations on a Theme. Living organisms are distinguished by their ability to reproduce their own kind. Heredity . is the transmission of traits from one generation to the next. Variation . is demonstrated by the differences in appearance that offspring show from parents and siblings. Review of Mitosis. Mitosis is a form of . asexual reproduction. This means that it . only requires 1 organism . (ex. Skin cells dividing). For growth and repair in . somatic. (body) cells!. Results in 2 cells identical to the original (parent) cell. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings. Cell Cycle. 3. A . life cycle. of an organism is the generation-to-generation sequence of stages in its reproductive history.. Asexual reproduction: Overview. Example #1: . Garlic (. Allium sativum. ) . “As far as we know, garlic in cultivation throughout history has only been propagated asexually by way of vegetative cloves, bulbs, and bulbils (or topsets), not from seed. These asexually propagated, genetically distinct selections of garlic we cultivate are more generally called "clones". Yet this asexual lifestyle of cultivated garlic forgoes the possibility of combining traits proffered by interpollinating diverse parental stocks.”. , depending . on the algal group. The main difference is obviously the DNA content that is . haploid instead . of diploid.. Different combinations of gamete types are . possible, . In the case of . isogamy. Cell division / Asexual reproduction. Mitosis. produce cells with same information. identical daughter cells. exact copies. clones. same amount of DNA . same number of chromosomes. same genetic information. 1. MEIOSIS AND SEXUAL LIFE . CYCLES. Heredity. = Continuity of biological traits from one generation to the . next. Variation. = Inherited differences among individuals of the same . species. Genetics. 1 identify the stages of meiosis. Only diploid cells caages of meiosis in a diploid cell where 2N = 6Meiosis involves 2 consecutive cell divisions. Since the DNA is duplicated result is 4 haploid cel Lydia R. Leonardo, DrPH. Biology 133 Lecture. Second Half. Module 2:.  . Reproductive Organs and the Sexual Cycle.  . SEXUAL CYCLES and HORMONAL ACTIONS IN MAMMALS. Male cycle and its hormones. Module 3: Gametogenesis.