9th Science NCERT Chapter 5

– Movement of substances into and out of the cell: Substances like carbon dioxide or oxygen move across the cell membrane through diffusion, where substances move from high to low concentration regions. This process is vital for gaseous exchange and water movement in cells. Osmosis is the specific diffusion of water across a selectively permeable membrane towards higher solute concentration.

– Cell responses to different solutions: When placed in hypotonic solutions, cells gain water and may swell; in isotonic solutions, there is no net movement of water; and in hypertonic solutions, cells lose water and shrink. These responses are due to osmosis, a type of diffusion.

– Organelles discussed in the chapter: Endoplasmic reticulum (ER), Golgi apparatus, lysosomes, mitochondria, plastids, and vacuoles are essential organelles in cells, each with specific functions such as protein manufacture, fat molecule synthesis, waste disposal, energy production, and storage.

– Mitosis and Meiosis: The process of cell division ('mitosis') creates identical daughter cells for growth and tissue repair, while reproductive cells divide through 'meiosis' to produce gametes with half the chromosomes. This process is crucial for reproduction across organisms.

These are some of the key topics covered in the chapter from the attached file【4:0†source】.