Cell Structure and Types Cells are the fundamental units of life and can be broadly classified into two types - prokaryotic and eukaryotic . Prokaryotic cells (...
Cells are the fundamental units of life and can be broadly classified into two types - prokaryotic and eukaryotic. Prokaryotic cells (e.g., bacteria) lack a true nucleus and membrane-bound organelles, while eukaryotic cells (e.g., animal and plant cells) possess these structures.
Cells can become specialised to perform specific functions, e.g., nerve cells for transmitting signals, muscle cells for contraction. Microscopes allow us to study cells at high magnification - light microscopes for general observation and electron microscopes for ultra-high resolution.
Problem: An object 2 mm long appears 50 mm on a microscope image. Calculate the magnification.
Solution:
Cells divide through the process of mitosis, producing two genetically identical daughter cells. This is part of the cell cycle and involves duplicating chromosomes, separating them, and splitting the cytoplasm.
Stem cells are unspecialised cells that can renew themselves through cell division and differentiate into various cell types. They play an important role in growth, repair, and development.
Movement of molecules across cell membranes occurs through various processes:
Living organisms exhibit hierarchical organisation from cells to tissues, organs, and organ systems. In humans, key systems include:
Disruptions to these systems can lead to non-communicable diseases like coronary heart disease and cancer.
Plants have specialised tissues like xylem (transports water/minerals) and phloem (transports food). They exhibit transpiration (water loss from leaves) and translocation (movement of dissolved nutrients).