BIOL 1201 Lecture : Ch13 Lecture Presentation Rev Spr 14
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Cindy s. malone, phd, california state university northridge. Meiosis promotes genetic diversity and allows the benefits of sex starting with by examining by asking. A sperm and an egg unite to form a new individual. Is nuclear division that precedes the formation of gametes. Results in a halving of chromosome number. Division of cytoplasm into two distinct cells. Every organism has a characteristic number of chromosomes. Is the number and types of chromosomes present in an organism. Sex chromosomes determine the sex of the individual. Humans have 46 chromosomes in every cell (except their gametes) Drosophila chromosomes drawn by nettie stevens in 1908 . Is a section of dna that influences one or more hereditary traits. Different versions of a specific gene are called alleles. But each one may contain different alleles. Gene for eye color (allele for red eyes) Gene for eye color (allele for purple eyes) The number of distinct types of chromosomes present.
