https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:useful-and-harmful-microorganisms/x345505a97fc4a662:antibiotics/v/antibiotics 2025-09-03T10:00:42.682314963Z Antibiotics Antibiotics are one of the greatest discoveries in science—but did you know their story begins with something as ordinary (and gross!) as mould? In this video, we’ll explore: 🔹 How people in ancient Egypt were already using bread mold to heal wounds. 🔹 The accidental discovery of Penicillin by Alexander Fleming. 🔹 How antibiotics fight bacteria inside our bodies. 🔹 Why antibiotics don’t work on viral infections (like colds & flu). 🔹 The big danger of antibiotic resistance—and what we can do about it. Bitasta Datta video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Antibiotics Antibiotics are one of the greatest discoveries in science—but did you know their story begins with something as ordinary (and gross!) as mould? In this video, we’ll explore: 🔹 How people in ancient Egypt were already using bread mold to heal wounds. 🔹 The accidental discovery of Penicillin by Alexander Fleming. 🔹 How antibiotics fight bacteria inside our bodies. 🔹 Why antibiotics don’t work on viral infections (like colds & flu). 🔹 The big danger of antibiotic resistance—and what we can do about it. https://cdn.kastatic.org/ka-youtube-converted/4KwCIvp2rQU.mp4/4KwCIvp2rQU.mp4 401 Antibiotics https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:useful-and-harmful-microorganisms/x345505a97fc4a662:antibiotics/e/antibiotics 2026-04-07T22:23:57.656416987Z Antibiotics This exercise dives deep into the fascinating world of antibiotics—not just what they are, but how they work, when they should (and shouldn't!) be used, and the science stories behind their discovery. Bitasta Datta exercise https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:useful-and-harmful-microorganisms/x345505a97fc4a662:antibiotics/e/useful-microbes 2025-11-25T10:10:42.36317656Z Useful microbes Learn how microbes help in making curd, bread, and fertile soil. This exercise from Chapter 8 “Useful and Harmful Microbes” covers Lactobacillus, Yeast, and Rhizobium with image-based and applied questions. Students explore fermentation, nitrogen fixation, and real-life examples of symbiotic relationships that benefit food and farming. Yajurva Joshi exercise