Plant and Animal Cells
Cell Biology
Under Construction
Components of a Cell Cells are the basic unit of life
Plant and animal cells are similar, but different in some ways
Cell walls, rigid outer coverings that contain high amounts of fiber, are found only in plant cells
Cell walls make it possible for plants to maintain their shapes.
A cell membrane is found inside the cell wall
The cell membrane is the flexible outer covering of an animal cell
Cells are usually permeable
Body and plant fluids move through cell walls to transport nutrients and remove wastes
Each cell has an oval-shaped nucleus
The nucleus contains the basic hereditary material through which traits are passed to offspring
Chromosomes are structures found in the nucleus
Chromosomes contain smaller structures called genes
Chromosomes are found in pairs
Each male and female parent furnishes one chromosome of each pair of offspring chromosomes
Genes contain information which determine characteristics inherited from parents
Protoplasm includes all of the structures and substances located witin the cell membranes, for both plants and animals.
It is made of salts, water, proteins, fats and carbohydrates
Protoplasm is divided into two types: Cytoplasm which includes all cell contents except the nucleus, and nucleoplasm the material found in the nucleus.
Plant cells contain two types of structures not found in animal cells: vacuoles and chloroplasts
Vacuoles collect wastes and excess water within the cell and discharge them through the cell walls.
Chloroplasts contain materials which can capture energy from the sun which is used to produce sugars and starches.
Many cell processes occur in rod-shaped cell structures called mitochondrion
These processes are controlled by enzymes
Animal cells have golgi apparatus which are made up of fibers, rods and granules
Cells divide into new cells throughout the lifetime of the living organism. This cell division, called mitosis causes growth to occur. See Animated Mitosis and Interactive Mitosis Tutorial (Shockwave Plugin)
The Cell Cycle
Also see Life Cycles and Mitosis
During mitosis, several steps occur. Each step is labeled as a phase:
  1. Interphase -- a resting stage of nonproductive stage
  2. Prophase -- Chromosome formation
    membrane around nucleus disappears
    chromosomes appear
    chromosomes have been replicated
    each half of the double cromosomes is called a chromatid.
    Chromatids are attached at the centromere. Also see Prophase.
  3. Metaphase -- chromosome alignment
    Chromosomes are pulled to the center of the cell by centrioles. Also see Metaphase
  4. Anaphase -- chromosome separation. Also see Anaphase
  5. Telophase -- cell division. Also see Telophase
  6. Interphase -- cells divided. See Cytokinesis
Meiosis

Meiosis

Phases of meiosis
  1. Prophase I
  2. Metaphase I
  3. Anaphase I
  4. Telophase I
  5. Prophase II
  6. Metaphase II
  7. Anaphase II
  8. Telophase II

Comparison of Mitosis and Meiosis

Online Biology Book
BioNotebook

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February 15, 2002