Class 9 Science The Fundamentals of Life Extra Question Answer
Q: Who first discovered cells?
A: Robert Hooke discovered cells in 1665 while examining a thin slice of cork under a microscope.
Q: What does a cell membrane do?
A: The cell membrane controls what enters and leaves the cell, acting as a selective barrier that allows some substances to pass through while blocking others.
Q: What is osmosis?
A: Osmosis is the movement of water through a special membrane from an area of higher water concentration to an area of lower water concentration.
Q: What are the main parts of a cell?
A: The main parts are the plasma membrane, nucleus, and cytoplasm.
Q: What is a prokaryotic cell?
A: A prokaryotic cell is a simple cell without a defined nucleus or membrane-bound organelles, like those found in bacteria.
Q: What is a eukaryotic cell?
A: A eukaryotic cell is a more complex cell with a defined nucleus and membrane-bound organelles, found in plants, animals, and fungi.
Q: What do mitochondria do?
A: Mitochondria are called the powerhouses of the cell because they produce energy in the form of ATP molecules.
Q: What is the function of chloroplasts?
A: Chloroplasts are responsible for photosynthesis in plant cells, helping plants convert sunlight into energy.
Q: What are lysosomes?
A: Lysosomes are cell organelles that act like a waste disposal system, breaking down old cell parts and foreign materials.
Q: How do cells divide?
A: Cells divide through two main processes: mitosis (for growth and repair) and meiosis (for creating reproductive cells).
Q: What is the cell wall made of?
A: In plant cells, the cell wall is mainly composed of cellulose, which provides structural strength.
Q: What do vacuoles do in plant cells?
A: Vacuoles store important substances, provide rigidity to the cell, and can occupy up to 90% of the cell’s volume.
Q: What are chromosomes?
A: Chromosomes are structures in the nucleus that contain genetic information (DNA) passed from parents to offspring.
Q: What is the endoplasmic reticulum (ER)?
A: The ER is a network of membranes in the cell that helps transport materials and can be involved in protein and lipid production.
Q: What is the Golgi apparatus?
A: The Golgi apparatus is an organelle that packages and distributes proteins and other materials within and outside the cell.
Q: What is the difference between chromoplasts and leucoplasts?
A: Chromoplasts contain pigments like chlorophyll, while leucoplasts are for storing materials like starch and proteins.
Q: Why are some cell organelles called membrane-bound?
A: Membrane-bound organelles are surrounded by a membrane that separates them from the rest of the cytoplasm.
Q: What happens during mitosis?
A: During mitosis, a mother cell divides into two identical daughter cells with the same number of chromosomes.
Q: What happens during meiosis?
A: During meiosis, a cell divides to produce four new cells with half the number of chromosomes of the original cell.
Q: How do plant cells differ from animal cells?
A: Plant cells have a cell wall, large vacuoles, and chloroplasts, which are not found in animal cells.
Q: What is the nucleus responsible for?
A: The nucleus controls cellular activities, stores genetic information, and plays a crucial role in cell division.
Q: How do single-celled organisms like Amoeba obtain food?
A: Amoeba uses a process called endocytosis to engulf food from its external environment.
Q: What makes the inner membrane of mitochondria special?
A: The inner membrane of mitochondria is deeply folded, which increases the surface area for energy production.
Q: Why are cells considered the fundamental unit of life?
A: Cells are the basic structural and functional units of all living organisms, performing essential life processes and serving as the building blocks of all living things.
Class 9 Science Tissue Extra Question Answer
