Cells

• What is the basic unit of life?

  A cell
• What is the primary function of a cell?

  A cell takes in raw materials and processes them to make new molecules
• How do cells transport new molecules?

  They either use these new molecules or transport them to other parts of the body
• Why can't most cells be seen with the naked eye?

  Because they are too small
• What tools do we use to study cells?

  Light and electron microscopes
• What is the maximum magnification of a light microscope?

  1000 times
• What type of images do light microscopes produce?

  Coloured light micrographs
• What is the maximum magnification of an electron microscope?

  200,000 times
• What is a micrograph?

  A micrograph is a picture of the cells
• How can a camera be used with microscopes?

  A camera can be fitted in either of the microscopes to take pictures of the cells
• What is protoplasm?

  Protoplasm is the living material found in a cell
• What are the components of protoplasm?

  Cell membrane, cytoplasm, and nucleus
• What is the function of the cell membrane?

  Controls the movement of substances in and out of the cell
• What is the structure of the cell membrane?

  It is a thin and delicate structure made up of lipids and proteins
• What is the cell wall and where is it found?

  The cell wall is a rigid structure found only in plant cells
• What are the functions of the cell wall?

  Protects plant cells from injury and gives them a fixed shape
• How does the permeability of the cell wall differ from the cell membrane?

  The cell wall is fully permeable, while the cell membrane is partially permeable
• What is cytoplasm?

  Cytoplasm is a jelly-like substance that fills the cells
• What occurs in the cytoplasm?

  Numerous chemical reactions occur in the cytoplasm
• What is the nucleus?

  The nucleus is an organelle surrounded by the nuclear membrane
• What are the functions of the nucleus?

  Controls cell activities, responsible for cell division, and contains genetic information
• What are chromosomes made of?

  Chromosomes are made up of proteins and deoxyribonucleic acid (DNA)
• What is the role of DNA in a cell?

  DNA stores hereditary information that provides instructions for cell activities
• What happens to chromosomes during cell division?

  Chromosomes condense and shorten to become thick, rod-shaped structures
• What is a vacuole?

  A vacuole is a fluid-filled cavity enclosed by a vacuolar membrane
• What is the function of a vacuole in a plant cell?

  Stores substances within the cell and contains cell sap
• How do vacuoles differ in plant and animal cells?

  Plant cells have a large central vacuole, while animal cells have small, numerous vacuoles
• What is the function of mitochondria?

  Mitochondria carry out aerobic respiration to release energy
• What do chloroplasts contain and what is their function?

  Chloroplasts contain chlorophyll which traps light for photosynthesis
• What are ribosomes and their function?

  Ribosomes are small round structures that synthesize proteins
• What are the differences between plant and animal cells?

  • Cell wall: Absent in animal cells, present in plant cells
  • Vacuole: Small and numerous in animal cells, large and central in plant cells
  • Chloroplasts: Absent in animal cells, present in plant cells
• What is differentiation in cells?

  • Differentiation is the process by which a cell becomes specialized for a specific function.
  • Cells have features in common but their structure relates to their function.
• How is a red blood cell adapted for its function?

  It contains haemoglobin, has no nucleus, and a biconcave shape
• How is a muscle cell adapted for its function?

  A muscle cell has mitochondria to provide energy for contraction
• How is a root hair cell adapted for its function?

  A root hair cell has an elongated structure to increase surface area for absorption
• What is a tissue?

  • A group of cells working together to perform a specific function.
  • Simple tissue: cells of the same type.
  • Complex tissue: more than one type of cell.
• What are organs and organ systems?

  • Organs are formed by different tissues working together.
  • Organ systems consist of organs working together, e.g., the digestive system.
• What is a multicellular organism?

  A multicellular organism is made up of many organ systems working together.