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About Seaweeds

Figure 8. The three-phased life cycle of the red seaweed Gracilariopsis. Separate haploid gametophytes, male (A) and female (D), produce non-motile sperm (B, C) and attached eggs (E). The sperm encounters a bowling pin–shaped egg and fuses with it (E). The resulting zygote develops into a parasitic diploid phase on the female gametophyte (F, G). This parasitic phase produces spores (H, I), which are released and develop into a free-living diploid phase (J). The free-living phase then produces spores (K, L) by meiosis (reduction cell division). These spores develop into male and female gametophytes—the sexual phase.

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B

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G

D

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F

H

I

J

K

L

syngamy

meiosis