11.3 Multicellular Life Cycles I. Diploid Life Cycle A. Meiosis in germ cells of a multicellular diploid organism results in the formation of haploid gametes B. Haploid gametes are the sperm & egg 1. Join together to form a diploid zygote C. Sperm cells undergo spermatogenesis D. Females produce gametes called eggs or ova (singular ovum) 1. Begins with a diploid germ cell

2. Results in the formation of two haploid 2. Results in the formation of two haploid cells with unequal amounts of cytoplasm a. the smaller cell is called the polar body b. the polar body can divide again but all offspring cells will die II. Haploid Life Cycle A. Happens in most fungi & some protists III. Alternation of Generations A. Plants & multicellular protists undergo this

B. Life cycle that alternates between a haploid phase & diploid phase C. Sporophyte 1. Plants in diploid phase D. Gametophyte 1. Plants in haploid phase