Students can go through AP Inter 1st Year Botany Notes 6th Lesson Modes of Reproduction will help students in revising the entire concepts quickly.
AP Inter 1st Year Botany Notes 6th Lesson Modes of Reproduction
→ Reproduction enables a species to live generation after generation.
→ Reproduction is broadly classified into Asexual and sexual types.
→ Asexual Reproduction : No Involvement of the gametes.
→ Asexual Reproduction is common in organisms that have a Relatively simple organisation such as the fungi and alqae.
→ The offsprings formed by Asexual Reproduction are
→ Identical and are referred to as clones.
→ In several algae and fungi, Asexual Reproduction occurs by forming Zoospores or conidia.
→ In Euglena, Bacteria, Asexual Reproduction occurs by Binary fission.
→ In yeats, Asexual Reproduction occurs by budding.
→ In Bryophytes and pteridophytes, the spores produced are haploid and on germination they produce gametophytes.
→ In multicellular or colonial forms of algae, moulds and mushrooms Asexual Reproduction takes place by fragmentation (ft is a type of vegetative Reproduction).
→ In some plants, Asexual Reproduction occurs by Gemmae (liver worts)
→ In Flowering plants, runners, stolons, suckers, offsets Rhizome, Corm, Stem tuber Bulb, Bulbil, Reproductive leaves, all are capable of giving rise to new offsprings.
→ Sexual Reproduction involves the formation of the male and female gametes either by the same individual or by different individuals of opposite sex.
→ Plants, the annual and biennial types show clear cut vegetative Reproductive and senescent phaennes.
→ Some of the grasses such as Rice, Maize, Wheat and bamboo species flower only once in their life time.
→ Century plant Agave americana and bamboo flower at the end of the life. Strobilanthus kunthiana flowers once in 12 years.
→ Sexual Reproduction is characterised by fusion of the male and female gametes, the formation of zygote and embryogenesis.
→ In some algae, the two gametes are so similar in appearance and are called Homo-gametes.
Ex : Cladophora.
→ In majority of the plants, the gametes produced are of two morphologically distinct called Heterogametes.
Ex : Funaria, Pteris, Cycas.
→ Several organisms belonging to monera, fungi, algae and Bryophytes have Haploid plant body.
→ In Pteridophytes, Gymnosperms and angiosperms, the plant body is diploid.
→ In diploid organisms, Meiocytes undergo meiosis.
→ The fusion of Male and Female gametes is called syngamy results in the formation of zygote.
→ Development of Embryo from an unfertilized female gamete is called parthenogenesis. In majority of Algae, syngamy occurs in the external medium called external fertilisation.
→ In Bryophytes, Pteridophytes, Gymnosperms and Angiosperms, Syngamy occurs inside the body of the organisms called Internal fertilisation.
→ Process of development of Embryo from the Zygote is called Embryogenesis.
→ After fertilization, the ovary develops into fruit, the ovules develop into seeds.
→ In Mangroves, the seeds germinate while still attached to the mother plant and is called Vivipary.
→ Apomizis : Replacement of the normal sexual reproduction by asexual reproduction, without fertilisation.
→ Asexual reproduction: Reproduction not involving the fusion of male and female gametes, as in vegetative reproductio, fission, or budding.
→ Clone: Asexually reproduced offspring.
→ Conidiophore : Specialized stalks on which conidiospores are formed.
→ Conidiospore/ conidium : Asexual non-motile spores of a fungus; also called as mitospores produced by conidiophore,
→ Dioecious : Presence of only one kind of sex organs either male or female on a single plant body.
→ Fragmentation: It is a form of asexual reproduction, where plant body breaks1 into fragments by mechanical methods.
→ Gamete : A cell that fuses with another cell during fertilisation in organisms that reproduce sexually.
→ Game togenesis : It is a process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes.
→ Gemmae : Cup like asexual reproductive structures in plants and fungi.
→ Heterothallic : Male and female reproductive organs develop on different thalli.
→ Homothallic : Having both male and female reproductive organs on the same thallus.
→ Karyogamy : It is the fusion of nuclei or genetic material of two cells, as part of syngamy, fertilisation, or bacterial conjugation.
→ Monoecious : Presence of both male sex organs and female sex organs on the same plant body.