Bio Exam 2 Review

Bio Exam 2 Review - Exam 2 Review Lecture 9 The earth is...

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Exam 2 Review Lecture 9 •The earth is about 4.6 billion yrs. old •Life originated about 3.8 billion yrs ago … •Most of the history of life is prokaryotic (and still is) •Life (photosynthesizers) changed earth for other life •Most of life that we recognize (e.g., vertebrates) are recent •In a time perspective, human history is but a tiny and very recent fraction of life •Yet, humans, despite their newcomer status, have altered the earth like no other previous life Lecture 10 Natural selection acts only on the component of a trait that is genetic , and evolution is concerned only with genetic changes in a population Old Hypothesis: Hypothesis 1 : Traits inherited from father •Hypothesis 2 : blended inheritance - Offspring receive a blend of information from mother and father Hypothesis 3 : Mendel’s hypothesis : Information is passed on as discrete particles . Each parent contributes a unit of information for a given trait, and each offspring has two units per trait True breeding : when two of this type crossed, all offspring look like parents Mendel’s conclusions Each individual has two units of information for a trait; e.g., both smooth (SS), wrinkled (ss), or one of each (Ss) There are different discrete forms of the units; e.g., purple, white, smooth, etc. Each parent gives
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This note was uploaded on 04/27/2008 for the course BIO 188 taught by Professor Capco during the Spring '08 term at ASU.

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Bio Exam 2 Review - Exam 2 Review Lecture 9 The earth is...

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