maddy final review

maddy final review - MadelineKaufman PRELIM1and2 1...

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Madeline Kaufman Biology 109-FINAL REVIEW PRELIM 1 and 2… 1. What are the traits (physical and cultural in correct order) that are associated with human evolution. Would an Australopithecine share all these traits (if not, which ones would be). Physical Traits: Bipedalism (upright walking) larger brain increasingly complex parental care language symbolic thought use complex tools pair bonding **australopithecine only bipedalism “Cultural Attributes” -- (* 1 st humans survived by scavenging, gathering and hunting) Stone tools fire construction of shelters language art music writing 2. Know the major events that happen during meiosis I [e.g. when do homologous chromosomes pair up] Mitosis: division of single nucleus into 2 genetically identical daughter nuclei I. Interphase a. Chromosomes duplicate and cell parts are made b. The cell grows during G 1 (“first gap”), continues to grow as it copies its chromosomes in S (synthesis), and then grows more as it completes preparations for cell division in G 2 (“second gap”) II. Mitotic Phase (M phase) a. Mitosis : the nucleus and its contents, including the duplicated chromosomes, divide and are evenly distributed to form 2 daughter nuclei b. Cytokinesis: the cytoplasm is divided in 2 c. 5 stages of Mitosis: i. Prophase : chromatin condenses to form sister chromatids and mitotic spindle begins to form but nucleus is still intact ii. Prometaphase : nuclear envelope fragments and spindle microtubules attach to the kinetochores of the sister chromatids iii. Metaphase : duplicated chromosomes are lined up at the equator of the dividing cell iv. Anaphase : sister chromatids separate from each other; ends when a complete set of daughter chromosomes has arrived at each of the 2 poles of the cell v. Telophase : final stage when daughter nuclei form at the 2 poles of the cell – actually occurs together w/ cytokinesis d. Citokinesis : 2 daughter cells completely separating soon after the end of mitosis – in animal cells, cytokinesis involves a cleavage furrow, which pinches the cell in 2 1
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MEIOSIS I and II Meiosis I: the first division starts with synapsis, the pairing of homologous chromosomes i. Separates each homologous pair and produces 2 daughter cells, each with 1 set of chromosomes ii. Interphase: chromosomes duplicate iii. Prophase I: I. synapsis occurs – homologous chromosomes, each w/ of 2 sister chromatids, come together as pairs II. crossing over occurs: exchange of corresponding segments of homologous chromosoes III. chromosome tetrads are moved toward the center of the cell iv. Metaphase I: homologous chromosomes of each tetrad move toward opposite poles of the cell v. Anaphase I: migration of chromosomes toward the two poles of the cell vi. Telophase I and Cytokinesis: chromosomes arrive at the poles– cytokinesis forms 2 daughter cells Meiosis II: chromosomes condense again and the nuclear envelope breaks down during prophase II – meiosis II is essentially the same as mitosis
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This note was uploaded on 04/04/2009 for the course BIO G 109 taught by Professor Winkler,d. during the Fall '06 term at Cornell.

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maddy final review - MadelineKaufman PRELIM1and2 1...

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