Fundamental Unit of Life One Shot in 20 Mins | Class 9th Science Chapter-5 | Vedantu Class 9

Recent questions

• What is a cell in biology?

  A cell is the basic unit of life, serving as the structural and functional building block of all living organisms. Cells are incredibly diverse, with trillions of them forming the human body alone, each performing essential life processes. They can be classified into two main types: prokaryotic and eukaryotic. Prokaryotic cells are simpler and lack a defined nucleus, while eukaryotic cells are more complex, containing a nucleus and various organelles that carry out specific functions. Understanding cells is fundamental to biology, as they are the foundation of all life forms.

• How do you define osmosis?

  Osmosis is the process by which water molecules move across a semi-permeable membrane from an area of higher water concentration to an area of lower water concentration. This movement is crucial for maintaining cellular homeostasis and is influenced by the surrounding solutions, which can be classified as hypotonic, isotonic, or hypertonic. In a hypotonic solution, cells swell as water enters; in an isotonic solution, there is balanced movement of water; and in a hypertonic solution, cells shrink as water exits. Osmosis plays a vital role in various biological processes, including nutrient absorption and waste removal.

• What are organelles in a cell?

  Organelles are specialized sub-cellular structures within a cell that perform distinct functions necessary for the cell's survival and operation. Each organelle has a specific role; for example, ribosomes are responsible for protein synthesis, while the endoplasmic reticulum (ER) is involved in the synthesis of proteins and lipids. The Golgi complex modifies and packages proteins for distribution, and mitochondria generate energy in the form of ATP. Other organelles, like lysosomes, contain digestive enzymes for breaking down waste materials. The presence of these organelles allows cells to carry out complex processes efficiently.

• What is the function of the nucleus?

  The nucleus serves as the control center of the cell, housing the cell's genetic material in the form of DNA. It is a double-membrane structure that contains the nucleolus, which is responsible for synthesizing ribosomes, essential for protein production. The nucleus regulates gene expression and cell division, ensuring that the correct proteins are produced at the right times. It plays a critical role in maintaining the integrity of genetic information and coordinating cellular activities, making it a vital component of eukaryotic cells.

• What is the role of mitochondria?

  Mitochondria are often referred to as the powerhouse of the cell due to their primary function of producing adenosine triphosphate (ATP), the energy currency of the cell. These double-membrane organelles have a unique structure that includes a porous outer membrane and a highly folded inner membrane, which increases the surface area for ATP synthesis. Mitochondria also contain their own DNA and ribosomes, allowing them to replicate independently within the cell. Their role extends beyond energy production, as they are involved in regulating metabolic processes and apoptosis, highlighting their importance in cellular health and function.