HW#5 Sex 2021 blank

BSCI 207 Fall, 2021 Sec. 0101 Dr. Haag 1 Homework #5: Sex 1. Isogamy vs. Anisogamy A. All multicellular organisms evolved anisogamy. In the model Dr. Eric shared, he posited two requirements of their gametes that contributed to sexual specialization. What were these? These two requirements were that the embryo needed to be large and the need to unite gametes over distance. B. In terms of fitness, how much better were specialized females than they would have been if they had remained isogamous? [Note: to answer this question, you will need to use the Excel file provided with Lecture 13.] If they remained isogamous, their fitness would decrease because there are less likely to produce viable offspring 2. Sex allocation Fill in the table below to help you learn the types of ways male and female can be packaged into organismal bodies: Sexual system Number of sexes Sex #1 Sex #2 (if present) Expected Frequency of outcrossing Hermaphrodite 1 one sex that makes both sperm and eggs none high Androdioecy 2 Hermaphrodite male low Parthenogenesis 1 Female (progeny genetic clones of mother) low Gynodioecy 2 Hermaphrodite female high Gonochorism/Dioecy 2 Male Female high Monoecy (plants) 1 Hermaphrodite with separate male and female flowers None low Autogamy 1 hermaphrodite eggs/ovules fertilized by sperm/pollen none low

BSCI 207 Fall, 2021 Sec. 0101 Dr. Haag 2 from the same individual In each of the life cycles below, indicate the following: • where meiosis, gamete formation, and fertilization (also known as “syngamy”) must occur • which parts of the cycle are diploid, and which haploid A. An animal (diplontic) B. A fern (haplodiplontic) sperm egg sperm egg gametophyte sporophyte Meiosis Fertilization Gamete formation Meiosis fertilization Gamete formation