Be familiar with the characteristics of eukaryotes outlined in class 1 Nucleus with nuclear envelope 2 Mitochondria 3 Cytoskeleton structure differs from prokaryotes 4 Flagella Cilia some extant eukaryotes lack flagella and or cilia but they are descended from ancestors that possessed them 5 Chromosomes consisting of linear DNA molecule coiled around histone proteins 6 Mitosis nuclear division wherein replicated chromosomes divided separated using elements of cytoskeleton 7 Sex process of genetic recombination in which diploid nuclei at one stage of the life cycle undergo meiosis to yield haploid nuclei subsequent stage where 2 haploid nuclei fuse to create a diploid zygote Characteristics of Eukaryotes 8 7 million species How did changes in the plasma membrane lead to the evolution of the first eukaryotes before endosymbiosis Cell size increases Endomembrane system of eukaryotes likely evolved from infolding of cell membrane of prokaryote ancestor Infolding eventually becomes independent of plasma membrane encloses nucleoid to form membrane bound nucleus Infolding also creates endoplasmic reticulum and Golgi apparatus Explain primary endosymbiosis as it relates to the mitochondrion and to the chloroplast Are the size of prokaryotes Have ribosomes Have circular chromosome that is independent of cell nucleus Duplicate in process like binary fission Have 2 membranes one from ancestral bacterium one phagosomal Mitochondrion engulfed energy producing bacterium Chloroplast engulfed photosynthetic bacterium Understand the steps of endosymbiosis and the evidence supporting the theory of endosymbiosis Aerobic proteobacterium enters eukaryotic cell as prey or parasite avoids digestion Proteobacterium becomes endosymbiont cell living within another cell What is secondary endosymbiosis How does it differ from primary endosymbiosis Endosymbiosis between eukaryotes eukaryotes Heterotrophic eukaryotes incorporate photosynthetic eukaryotes as endosymbionts 2 endosymbiosis heterotrophic eukaryotes incorporate photosynthetic eukaryotes as endosymbionts At least some of nuclear DNA of endosymbiont moved to secondary host nucleus Chloroplast acquired by secondary endosymbiosis has 3 membranes 4 th lost over time Be familiar with the characteristics of eukaryotes outlined in class 1 Nucleus with nuclear envelope 2 Mitochondria 3 Cytoskeleton structure differs from prokaryotes 4 Flagella Cilia some extant eukaryotes lack flagella and or cilia but they are descended from ancestors that possessed them 5 Chromosomes consisting of linear DNA molecule coiled around histone proteins 6 Mitosis nuclear division wherein replicated chromosomes divided separated using elements of cytoskeleton 7 Sex process of genetic recombination in which diploid nuclei at one stage of the life cycle undergo meiosis to yield haploid nuclei subsequent stage where 2 haploid nuclei fuse to create a diploid zygote Characteristics of Eukaryotes 8 7 million species Aerobic respiration use of O2 to make energy by aerobic endosymbiont benefits host cell Eventually endosymbiont becomes assimilated into cell as mitochondrion Some heterotrophic eukaryotes with mitochondria go on to acquire cyanobacteria as endosymbionts Cyanobacteria eventually become assimilated as chloroplasts This leads to the first photosynthetic eukaryotes