RBSE Class 12 Biology Notes Chapter 1 Reproduction in Organisms

These comprehensive RBSE Class 12 Biology Notes Chapter 1 Reproduction in Organisms will give a brief overview of all the concepts.

These RBSE Solutions for Class 12 Biology in Hindi Medium & English Medium are part of RBSE Solutions for Class 12. Students can also read RBSE Class 12 Biology Important Questions for exam preparation. Students can also go through RBSE Class 12 Biology Notes to understand and remember the concepts easily.

RBSE Class 12 Biology Chapter 1 Notes Reproduction in Organisms

→ Reproduction : Reproduction is a biological process by which an organism produces another organism (offspring) similar to itself.

→ Reproduction is necessary for the continuity of the species. All the reproductive methods are broadly categorised into two types : Asexual reproduction and Sexual reproduction.

→ Asexual reproduction : It is the production of offsprings by a single parent and is does not involve gametic fusion.

→ Asexual reproduction is common in unicellular organisms such as algae, fungi, protozoans and some invertebrates.

→ The various methods of asexual reproduction are : Fission, Budding, Fragmentation, Regeneration. Spore formation and vegetative propagation.

RBSE Class 8 Biology Notes Chapter 1 Reproduction in Organisms

→ Most of the prokaryotes (e.g., Bacteria) and unicellular protists (e.g,, Amoeba, Paramecium) reproduce by binary fission.

→ Budding is common in yeast and Hydra.

→ Multiple fission is common reproducing method for Amoeba and Plasmodium.

→ Fragmentation mathod of asexual reproduction is very common in algae (e.g., Spirogyra) and Fungi (e.g., Vaucheria).

→ Regeneration is most commonly shown in Planaria.

→ Spore formation is the most common means of asexual reproduction in algae and fungi. The main types of spores are zoospores, sporangiospores, conidia, gemmules, chlamydospores and oidia.

→ Vegetative reproduction : It is a mode of reproduction in which new plants are formed from vegetative parts of the plant like roots, stems, leaves etc.

→ Vegetative reproduction is of two main types : Natural vegetative reproduction and Artificial vegetative reproduction.

→ The natural methods of vegetative reproduction involve some specialised structures namely, runners, suckers, rhizome, tubers, corm, bulbs, stolon, offset etc.

→ Artificial methods of vegetative reproduction have been developed by plant growers and Horticulterists for commercial production of economically important plants. These methods include : cutting, grafting, layering, bud grafting and micropropagation.

→ Vegetative propagation is the only method of reproduction in plants which have lost their capacity to produce seeds.

→ Sexual Reproduction : Sexual reproduction is the production of offsprings by the formation and fusion of specialized male and female cells, called gametes.

→ There are three events of sexual reproduction : Pre-fertilization events (It includes formation of zygote and embryogenesis). It includes gametogenesis and gamete transfer. Fertilization (it is also known as syngamy) and post-fertilization events. (It includes formation of zygote and embryogenesis).

→ Fertilization is the fusion of male and female gametes to form a diploid cell called zygote.

→ The phenomenon of development of female gamete directly into an individual without fertilization is called parthenogenesis.

→ Based on whether the zygote develops outside the body of female parent or inside, animals can be classified into oviparous and viviparous respectively.

→ Reproduction : Process by which an organism produces another organism.

→ Life-span : The period from birth to the natural death of an organism.

→ Asexual reproduction : Production of offspring by a single parent and it does not involve gametic fusion. Haploid : The condition of cell/organism in which only one set of chromosomes is present. 

RBSE Class 8 Biology Notes Chapter 1 Reproduction in Organisms

→ Diploid : The condition of cell/organism in which pairs of chromosomes are present.

→ Clone : The exact copy of parent is called clone.

→ Binary fission : The splitting of a parental cell into two equal daughter cells, is called binary fission.

→ Multiple Fission : The splitting of a parent cell into numerous daughter cells is called multiple fission.

→ Sporulation : The formation of spores to reproduce offsprings is called sporulation.

→ Regeneration : A process in which the missing part of an organism is repaired by proliferation of cells.

→ Zoospores : Endogenously produced unicellular, naked and motile spores.

→ Conidia : Asexual, non-motile spores cut off externally either singly or in chains.

→ Gemmules: Internal asexual reproductive units or buds.

→ Vegetative propagation : A mode of reproduction in which new plants from vegetative part of parent plant.

→ Sexual reproduction : A method of reproduction which involves the fusion of male and female gametes to form a zygote.

→ Gamete : Haploid sexual cell, such as sperm or egg.

→ Gametogenesis : The process of formation of garnets (i.esperms and ova) is called gametogenesis.

→ Oestrous cycle : Characteristic cyclic changes start in non-primate females.

RBSE Class 8 Biology Notes Chapter 1 Reproduction in Organisms

→ Menstrual cycle : Characteristic cyclic changes start in female primates.

→ Monoecious : An individual which can produce both male and female gametes is called monoecious, bisexual or hermaphrodite.

→ Dioecious : An individual which produce only one kind of gametes, is called dioecious or unisexual.

→ Pollination : Transfer of pollen grains to stigma.

→ Zygote : Diploid cell, produced by the fusion of two haploid gametes.

→ Embryogenesis : Development of young one from zygote.

→ Oviparous : Animals which lay egg.

→ Viviparous: Animals which give birth to young ones.

→ Parthenogenesis : Development of embryo from unfertilized female gamete called parthenogenesis.

Prasanna
Last Updated on Aug. 1, 2022, 3:43 p.m.
Published June 15, 2022