Download Lesson 3.2– LEVELS OF ORGANIZATION (NB p. 109

Lesson 3.2– LEVELS OF ORGANIZATION (NB p. 109-111)
Summarize life’s organization:
All organisms are made of cells.
Organize information about unicellular organisms:
Prokaryotes – cells without a membrane-bound nucleus; smaller than eukaryotes; some live in extreme environments
Eukaryotes – cells with a nucleus surrounded by a membrane; many specialized organelles
All unicellular organisms have the ability to
- Obtain food energy
- Repond to their environment
- Grow and develop
- Reproduce through basic cell division called binary fission
Compare and contrast:
Unicellular organisms are…
- made of one cell
- processes needed for survival are carried out within one cell
Multicellular organisms are…
- made of many cells
- each type of (specialized) cell has a function that is important to the organism
Both unicellular and multicellular organisms carry out all life processes
Organize information about cell differentiation:
Cell differentiation is the process by which cells become different types of specialized cells
In plants, cell differentiation occurs in meristem cells found in roots and stems
In animals, cell differentiation occurs in stem cells found in embryos and adult bone marrow
Stem and meristem cells are unspecialized cells that are able to develop into many different cell types
Identify 4 main types of animal tissue: Muscle, connective, nervous and epithelial
Identify 3 main types of plant tissue, and tell the function of each:
Dermal – provides protection and helps reduce water loss
Vascular – transports water and nutrients from one part of a plant to another
Ground – provides storage and support and is where photosynthesis takes place
Sequence the organization of cells, tissues, organs and organ systems in a multicellular organism:
Cells are organized in multicellular organisms;
Different cells working together to perform a particular job are called tissue;
Groups of tissue that work together to complete a series of tasks are called organs;
Many organs working together make up an organ system.
Connect It: The cells of all your organs have the same DNA in their nuclei, yet all perform different jobs in your body.
Explain how this can be so. Use the term cellular differentiation in your explanation.
Cellular differentiation results in different cell types using different parts or sections of the DNA on chromosomes,
so that each has a different and unique set of instructions that code for a specific function.