Phylum Porifera | Diversity in Living Organisms | Grade 9 | Biology | Khan Academy

In this video, we’ll learn about Phylum Porifera — the simplest animals on Earth that started it all! We’ll explore how these pore-bearing creatures, known as sponges, survive without organs, yet efficiently feed, breathe, and reproduce through a unique canal system. You’ll discover the roles of special cells like choanocytes and amoebocytes, and understand how sponges act as natural water filters that keep aquatic ecosystems healthy. By the end, you’ll see why sponges are truly nature’s simplest yet smartest design — quiet, ancient, and incredibly fascinating! Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! (https://www.khanacademy.org/science/t...) Timestamps: 0:00 – Introduction: The World of Sponges 0:30 – How Can Sponges Live Without Organs? 0:43 – Habitat and Body Shape (Asymmetry & Sessile Nature) 1:06 – Sponge Body Design & Structure 1:19 – Water Flow System: Ostia, Spongocoel & Osculum 1:40 – Specialized Cells: Pinacocytes, Choanocytes & Amoebocytes 2:36 – Canal System: Ascon, Sycon & Leucon Types 3:29 – Skeleton of Sponges: Spicules & Spongin 3:57 – Cellular Level of Organisation 4:15 – Feeding, Digestion & Respiration (Filter Feeders) 4:51 – Asexual Reproduction: Fragmentation, Budding & Gemmules 5:20 – Sexual Reproduction & Hermaphroditism 6:05 – Internal Fertilisation & Larval Stage 6:23 – Examples of Sponges (Sycon, Spongilla, Euplectella) 6:43 – Summary: Key Features of Phylum Porifera 7:13 – Closing Thoughts: The Humble Beginning of Animal Life Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy