Structure & Function in Living Organisms
Cells, Tissues, Organs & Organ Systems:
Cells are made up of structures called organelles, such as the nucleus, mitochondria and ribosomes
In complex multicellular organisms:
Cells are specialized to carry out particular functions
These specialized cells form tissues
The tissues form organs
The organs form organ systems
Organelle → Cell → Tissues → Organ → Organ system → Organism
Animal V.S. Plant cell
Animal cell
Structure | Function |
Nucleus |
|
Cytoplasm |
|
Cell membrane |
|
Mitochondria |
|
Ribosome |
|
Structure | Function |
Nucleus |
|
Cytoplasm |
|
Cell membrane |
|
Mitochondria |
|
Ribosome |
|
Cell wall |
|
Chloroplast |
|
Permanent vacuole |
|
Cell differentiation is an important process by which a cell changes to become specialised
Specialised cells are those that have developed certain characteristics that allow them to perform particular functions. These differences are controlled by genes in the nucleus
As a multicellular organism develops, its cells differentiate to form specialised cells
In an animal, most cells differentiate at an early stage of development
As a result, animal cells lose their ability to differentiate early in the life of the organism
Specific cells in various locations throughout the body of an animal retain the ability to differentiate throughout the life of the animal
These undifferentiated cells are called adult stem cells and they are mainly involved in replacing and repairing cells (such as blood or skin cells)
Plants differ from animals in that many types of plant cells retain the ability to fully differentiate throughout the life of a plant, not just in the early stages of development
Example of specialized animal cells:
Example of specialized plant cells:
Cells, Tissues, Organs & Organ Systems:
Cells are made up of structures called organelles, such as the nucleus, mitochondria and ribosomes
In complex multicellular organisms:
Cells are specialized to carry out particular functions
These specialized cells form tissues
The tissues form organs
The organs form organ systems
Organelle → Cell → Tissues → Organ → Organ system → Organism
Animal V.S. Plant cell
Animal cell
Structure | Function |
Nucleus |
|
Cytoplasm |
|
Cell membrane |
|
Mitochondria |
|
Ribosome |
|
Structure | Function |
Nucleus |
|
Cytoplasm |
|
Cell membrane |
|
Mitochondria |
|
Ribosome |
|
Cell wall |
|
Chloroplast |
|
Permanent vacuole |
|
Cell differentiation is an important process by which a cell changes to become specialised
Specialised cells are those that have developed certain characteristics that allow them to perform particular functions. These differences are controlled by genes in the nucleus
As a multicellular organism develops, its cells differentiate to form specialised cells
In an animal, most cells differentiate at an early stage of development
As a result, animal cells lose their ability to differentiate early in the life of the organism
Specific cells in various locations throughout the body of an animal retain the ability to differentiate throughout the life of the animal
These undifferentiated cells are called adult stem cells and they are mainly involved in replacing and repairing cells (such as blood or skin cells)
Plants differ from animals in that many types of plant cells retain the ability to fully differentiate throughout the life of a plant, not just in the early stages of development
Example of specialized animal cells:
Example of specialized plant cells:
