Bio 172 Exam 1 Questions and Answers Rated A+

Bio 172 Exam 1 Questions and Answers Rated A+ What are the events that take place in a sexual cycle and why is this cycle significant? - Gamete formation (1n Haploid) -Fertilization (Syngamy) of gametes. -Zygote formation. Zygote is first 2n (Diploid) cell. Then recombination occurs (Basically, Haploid cells (Gamete and spirm) form to create Diploid cell (Zygote)) What is the first supergroup? Excavata What is asexual reproduction? One parent, and offsprings are identical clones to parent. What are the 3 organisms of sexual life cycles and how do they differ regarding what undergoes/is a product of meiosis? -Animal (& some protists) Gametes are product of meiosis! -Fungi (& some protists) Zygote undergoes meiosis! -Plants (& some algae) Spores are product of meiosis! Why are cells of protists the most complex eukaryotic cells? All functions are carried out in cell by organelles. In unicellular species carries out all function or organism. What was the driving force of evolution? Which of these came first and why? nucleus, endoplasmic reticulum, mitochondrion or chloroplast (plastid). Symbiosis as the driving force in evolution! Mitochondrion came first since it is present in ALL eukaryotes. (Plants have chloroplasts) Through lateral transport, the nuclear genome of eukaryotes should be a mixture of bacteria and eukaryotes, but it is not. Instead it also includes sequences of the Archaea, as well. How was this explained. Eukaryotes derived from community of cells freely exchanging DNA. (mixture of Bacteria, Archaea and Eukaryotes.) Explain what the major flaw was, in Whitaker's kingdom Protista and how it was eventually remedied. Eukaryotes that are not plants, fungi or animals. Protists are therefore polyphyletic. Advances in molecular systematics has led to redefining organisms into "Super Groups" What are the characteristics of Parabasalids and Diplomonads? Why were they once thought to have diverged early in the evolution of eukaryotes? Anaerobic. Thought to be amitochondriate. Has modified mitochondria. Mitosomes & hydrogenosome, respectively. Free living and parasitic. Flagellated, 2 to many. What is a distinguishing structural characteristic of Euglenozoans? Flagellated, crystalline rod inside of flagella. What is a readily observable characteristic that indicates that the Euglenids are a product of secondary endosymbiosis? Photosynthetic species' chloroplasts with 3- membrane layers. Indicates secondary endosymbiosis! What are the characteristics of Kinetoplastids? Unicellular with one large mitochondrion. Associated with kinetoplast kinetoplast containing extranuclear DNA. African Sleeping Sickness is caused by Trypanosoma. What is the vector of this disease? Why is it impossible for the host to develop an immunity to this disease. Vector = Tse Tse Fly Treatable, if detected early. Molecular change in coat prevents immunity