BioG 1109 prelim2words

BioG 1109 prelim2words - Prelim#2 Study Guide Deuterostome...

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Prelim #2 Study Guide Deuterostome: main opening becomes the anus Echinodermata: slow moving or sessile marine animals (sea stars, sand dollars, and sea urchins) that are usually radially symmetrical; have water vascular system and tube feet notochord : a flexible, supportive, longitudinal rod located between the digestive tract and the nerve cord Operculum : a protective flap that covers a chamber housing the gills, breathe without swimming Swim Bladder : lung derivative that helps keep them buoyant, a gas filled sac Mammalia: probably started as small, nocturnal insect eaters cell cycle : ordered sequence of events that extends from the time a cell is first formed from a dividing parent cell until its own division into two cells Interphase : most of the cell cycle is spent here, metabolic activity is very high and the cell performs its various functions within the organism, increases supply of proteins, creates more cytoplasmic organelles, and grows G1: first gap, growth S : more growth, copying of chromosomes G2: grows more, completes preparations for cell division M: cell actually divides, 10% of time Mitosis: nucleus and contents, including duplicated chromosome, divide and are evenly distributed to form 2 daughter nuclei Prophase: chromatin fibers become more tightly coiled and folded (chromosomes), nucleoli disappear, duplicated chromosomes appear as 2 identical sister chromatids, mitotic spindle begins to form as microtubules rapidly grow out from the centrosomes in the cytoplasm Prometaphase: nuclear envelope breaks into fragments and disappears, microtubules emerge from centrosomes at poles, each sister chromatid has a kinetochore, which is a protein structure Metaphase: mitotic spindle fully formed, chromosomes convene on metaphase plate in the middle Anaphase : two centromeres of each chromosome come apart, separating sister chromatids into daughter chromosomes, spindles with chromatids shorten and bring them to poles, other spindles lengthen; over when equivalent and complete collections of chromosomes have reached the two poles of the cell Telophase: reversal of prohpase, cell elongation that started in anaphase continues, daughter nuclei appear at two poles of cell as nuclear envelopes form around chromosomes, chromatin fiber uncoils and nucleoli reappear, mitotic spindle disappears, now finished Cytonkinesis: division of cytoplasm, 2 daughter cells completely separating meiosis: type of cell division that produces haploid gametes in diploid organisms (two sets of division) meiosis I : homologous chromosomes separate meiosis II: sister chromatids separate haploid: N diploid: 2N crossing over : an exchange of corresponding segments between two homologous chromosomes, happens on the chiasma Law of independent assortment: Mendel, states that each pair of alleles segregates independently of the other pairs of alleles during gamete formation
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This note was uploaded on 11/18/2008 for the course BIO 1109 taught by Professor -2 during the Fall '08 term at Cornell.

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BioG 1109 prelim2words - Prelim#2 Study Guide Deuterostome...

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