UNIT 4 The reproduction function ALTERNATION OF GENERATIONS IN A FERN Natural Science 2. Secondary Education

UNIT 4 Alternation of generations in a fern Sporangium Gametophyte Zygote Young sporophyte Male sexual organ Female sexual organ Male gametes Female gamete Click on each picture to find out more The different stages of the process Sporophyte Sexual organs of the gametophyte Natural Science 2. Secondary Education

This is the part of the fern that we can see. On the underside of its leaves, called fronds, are the sporangia. Sporophyte Frond Sporangium Go back to the Start menu UNIT 4 Alternation of generations in a fern Natural Science 2. Secondary Education

This is where spores are formed and mature. Gametophytes come from spores. Sporangia Sporangium Spores UNIT 4 Alternation of generations in a fern Go back to the Start menu Natural Science 2. Secondary Education

They develop from spores. They are very small. They have sexual organs, which produce male and female gametes. Gametophytes Gametophyte Male sexual organ Female sexual organ Male gametes, which need water in order to reach the female organ. Female gamete UNIT 4 Alternation of generations in a fern Go back to the Start menu Natural Science 2. Secondary Education

The union of a male gamete and a female gamete produces the zygote. The development of the zygote produces a new sporophyte. Zygote Young sporophyte Sporophyte UNIT 4 Alternation of generations in a fern Go back to the Start menu Natural Science 2. Secondary Education