1. Figure 27.9

2. Figure 27.29

3. The Algae haploid and diploid cells – undergo mitosis and alternation of generations. – diploid sporophyte generation forms spores by meiosis in sporangium – The haploid gametophyte generation forms gametes by mitosis – Gametes fuse to yield zygotes – Form the next generation of sporophytes.

4. Sexual reproduction – if gametes are identical it is isogamous: isogamy – if gametes are different it is heterogamous: Anisogamy: gametes differ in size or form only Oogamy: large non-motile egg and motile male gametes – sex organs are gametangia – sporangia form from gametangia male (sperm) within antheridia female egg is called oogonia formed within the archogonium

5. Figure 27.22

6.  probable ancestors of the green plants(charophytes)  lines of evidence:  chloroplasts morphologically and biochemically similar to plants  cellulose rich cell walls  Photosynthetic pigments include:  chlorophyll a and b  Carotenoids  starch as primary storage product  formation of an interior cell plate growing from the center outward during cytokinesis (cell division)

7.  very little tissue differentiation  algae body- thallus (Thallophyta)  division of the plant kingdom  mostly aquatic, some semi-terristrial  moist places- soil, tree trunks  exhibit alternation of generations  Contain chlorophyll a and b  accessory pigments of carotene and xanthophyll  contain pyrenoids storage for starch synthesis  cell walls contain cellulose and pectin

8.  Chlamydomonas- microscopic single cells with flagella (anterior), eyespot within chloroplast containing rhodopsin  haploid through most of life cycle- reproduce both sexually (zygotic meiosis) and asexually (common)  asexual form zoospores  may divide and not separate to form colony  Sexual:  zygote develops thick wall to become a zygospore (resting phase- looses its flagella)  isogamy (most primitive condition)  only diploid stage is the zygote

9. Ulva- sea lettuce large multicellular eaten in soups and salads used as a substitute for nori Chlorella Single celled, no flagella food source for animals and humans pilot farms in US, Germany, Israel and Japan Ulothrix reproduce by fragmentation or asexual spores sexual reproduction isogamous to form zygote which divides by meiosis

10. Chlamydomonas Volvox Volvocine Series: Explanation of multicellularity and differentiation

11. Figure 27.26

12. Reproduction in Filamentous Green Algae