REPRODUKSI TUMBUHAN PADA TUMBUHAN BERBUNGA

REPRO. TUMBUHAN Jelaskan faktor yang mempengaruhi benih dalam biji dapat tumbuh ?. Sebutkan bagian-bagian bunga dan biji tumbuhan dan jelaskan fungsi masing-masing bagian tersebut, bagian apa yang haploid, diploid, triploid ?. Jelaskan cara-cara serbuk sari pindah dari satu tempat lain ?. Jelaskan peristiwa penyerbukan dan apa bedanya dengan pembuahan ? Jelaskan kronologi terjadinya penyerbukan dan pembuahan ?

Jelaskan faktor-faktor yang mempersulit penyerbukan ? Bagaimana caranya tumbuhan (mis. Aggrek) berusaha keras agar terjadinya penyerbukan ? Bagaimana cara-cara alat reproduksi tumbuhan disebarkan ke tempat lain yang jauh dari keberadaannya ? Bagaimana peran udara, air, makhluk hidup, dan lainnya dalam reproduksi tumbuhan ?

LIFE CYCLE OF FOWERING PLANTS Flowering plant life cycles proceed through a multicelled diploid stage (the sporophyte) and multicelled haploid stage (the gametophyte). The sporophyte is a multicelled vegetative body with roots, stems, leaves, and, at some point, flowers.

A TYPICAL FLOWER A typical flower has sepals, petals, one or more stamens (male), and carpels (female), most or all attached to a receptacle (the modified end of a floral shoot). The sepals and petals, non-fertile part of flower. The stalked anther of stamens contain pollen sacs, cells divide by meiosis, and resulting haploid cells, microspores. These develop into sperm-bearing pollen grains (male gametophyte). A carpel is female reproductive part. A single carpel has an ovary, egg develop, fertilization takes place, and seed mature. A stigma, a sticky or hairy surface tissue that captures pollen grains and promotes their germination. Often the upper portion of the ovary is modified into a slender column (style)

DEVELOPMENT OF GAMETOPHYTE AND FERTILIZATION Male gametophyte develop in the anther. Female gametophyte develop in the ovary. After fertilization, ovule mature into a seed Double fertilization, zygote (2n) and endosperm (3n) nutritive tissue. Ovary develops into a fruit. Fruits function to protect and disperse seeds.

POLLINATION Flowering plants have coevolved with air currents, animals, and other agents that help the transfer of pollen grain to suitable stigma.