Asexual Reproduction Important FOR Group-D Exam || Quick Revision || скачать в хорошем качестве

Asexual Reproduction Important FOR Group-D Exam || Quick Revision ||

Asexual Reproduction Important FOR Group-D Exam || Quick Revision || #science #asexual_reproduction ✅ ASEXUAL REPRODUCTION – COMPLETE DETAILED NOTES 🔷 1. What is Reproduction? Reproduction is the biological process by which living organisms produce new individuals of the same species. 🔹 It ensures: Continuity of life Survival of species Transfer of hereditary characters 🔷 2. What is Asexual Reproduction? ✅ Asexual reproduction is the type of reproduction in which: Only one parent is involved No formation of gametes (sex cells) No fertilization occurs Offspring are genetically identical to the parent (called clones) 🔹 Common in: Bacteria Amoeba Hydra Fungi Plants like potato, onion, banana 🔷 3. Characteristics of Asexual Reproduction Feature Description Parents involved Only one Genetic variation Absent Speed Very fast Energy required Very less Evolution Does not promote evolution Offspring Exact copy of parent (clone) 🔷 4. Importance of Asexual Reproduction ✅ Helps in: Rapid increase in population Colonization of new areas Survival of organisms in stable environments Agricultural propagation of useful plants ✅ TYPES OF ASEXUAL REPRODUCTION (VERY IMPORTANT) 🔶 1. Fission 👉 Parent cell divides into new individual cells. (a) Binary Fission One parent → Divides into two equal individuals Examples: Amoeba Paramecium Bacteria Steps: 1. Nucleus divides 2. Cytoplasm divides 3. Two daughter cells formed ✅ Each daughter cell grows into a new organism. (b) Multiple Fission Parent → Divides into many individuals at once Example: Plasmodium (malaria parasite) Occurs under unfavourable conditions → forms cyst → many daughters released when conditions improve. 🔶 2. Budding 👉 A small outgrowth (bud) develops on the parent, grows, and separates. Examples: Hydra Yeast Steps: 1. Bud forms on parent 2. Grows by mitosis 3. Detaches and becomes a new individual ✅ Parent is not destroyed. --- --- 🔶 3. Fragmentation 👉 Parent body breaks into fragments, and each fragment grows into a new organism. Example: Spirogyra (algae) ✅ Occurs in simple multicellular organisms. --- --- 🔶 4. Regeneration 👉 Ability of an organism to regrow lost body parts and even form a whole new individual from a body fragment. Examples: Planaria Starfish Hydra ✅ Based on specialized cells that divide and differentiate. --- --- 🔶 5. Spore Formation 👉 Spores are tiny, thick-walled asexual reproductive structures formed inside sporangia. Examples: Rhizopus (bread mould) Mucor Penicillium Features: Light-weight Dispersed by air Survive unfavourable conditions Steps: 1. Sporangia form on hyphae 2. Spores develop 3. Sporangium bursts 4. Spores germinate in favourable conditions --- --- 🔶 6. Vegetative Propagation (In Plants) 👉 A new plant grows from root, stem, or leaf instead of seeds. Natural Methods: Part Example Stem Potato, Ginger, Sugarcane Root Sweet potato Leaf Bryophyllum --- Artificial Methods: ✅ Cutting – Rose ✅ Layering – Jasmine ✅ Grafting – Mango ✅ Tissue culture – Banana, orchids --- --- ✅ ADVANTAGES OF ASEXUAL REPRODUCTION ✅ Only one parent needed ✅ Fast reproduction ✅ Large number of offspring ✅ Useful in agriculture ✅ Preserves desirable characters --- ❌ DISADVANTAGES OF ASEXUAL REPRODUCTION ❌ No genetic variation ❌ No evolution ❌ All offspring vulnerable to diseases ❌ Adaptability is poor --- ✅ DIFFERENCE BETWEEN ASEXUAL AND SEXUAL REPRODUCTION Asexual Sexual One parent Two parents No gametes Gametes formed No fertilization Fertilization occurs Fast Slow No variation Variation present No evolution Evolution occurs -- 1. Define asexual reproduction. 👉 Reproduction involving one parent without fusion of gametes. 2. Name organism that shows: Binary fission – Amoeba Budding – Hydra