4.3 Multicellular Organization
Unicellular
One cell carries out everything.
Multicellular
*Cells are differentiated to perform specific functions.
Cells make up Tissues that make up Organs that make up Organ Systems that make up Complete Organisms.
Cells The basic unit of life.
Tissues A group of
similar cells which carry out a common function.
Organ Several types of
body tissues that together form a function. Examples are stomach, lungs, heart.
Organ System
A group of organs that interact to perform a set of related tasks. Examples of organ systems are; digestive, respiratory, reproductive, endocrine, immune, urinary.
Organ SystemThe digestive
system is made up of the following organs: mouth, esophagus, stomach, large intestines, small intestines, pancreas, gall bladder.
Organism
Living things.
Specialized Tissues (“MENC”)
Muscle
*contraction
Epithelial
*surface covering
Nervous
*transmits messages
Connective
*support and link together
Specialized Tissues Example of specialized
tissues.Take cells that make
up the stomach. *muscle tissue causes
movement. *epithelial tissue secretes
enzymes. *nervous tissue transmits
messages back and forth from stomach to brain.
*connective tissue holds stomach together.
Plants have Tissues and Organs
Vascular tissue transports water and nutrients from leaves to roots and from roots to leaves.
Organs are roots, stems, leaves.
Prokaryotes *First cells on Earth. * Evidenced by fossils Did not produce own food. Depend on nutrients in environment.*Through evolution, these cells started to
compete for the environment and cells with adaptations evolved. These were eukaryotes.
Colonial Organisms
A collection of genetically identical cells that live together in a closely connected group and each cell group has its own function.
The green alga known as volvox is the evolutionary link between unicellular organisms and multicellular organisms. It still lacks tissues and organs.
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