Levels of Organization : Levels of Organization Overview of Cells : Overview of Cells In unicellular (single-celled) organisms, the single cell performs all life functions. It functions independently.
However, multicellular (many celled) organisms have various levels of organization within them.
Individual cells may perform specific functions and also work together for the good of the entire organism.
The cells become dependent on one another.
A cell is the simplest living thing that can have a "life of its own.“
Germs (viruses and bacteria) are smaller than cells and most can not survive alone. To survive, many germs have to invade cells and steal some of the functions of cells, often damaging cells in the process. Levels of organization, showing relation of atoms to cells to organisms. : Levels of organization, showing relation of atoms to cells to organisms. organelles : organelles Literally, the term means "little organs." Inside a cell, there are various little structures that perform specific functions, much like the multicellular organs of our body do. In the cell, these include generating energy (the organelle is the mitochondrion), making proteins (the organelles are ribosomes and Golgi apparatus), and others. Slide 6: the smallest unit of life, a cell is a collection of organelles functioning together
Are the basic unit of structure and function in living things.
May serve a specific function within the organism
Examples- blood cells, nerve cells, bone cells, etc. Cells Tissues - a collections of cells working together to perform a specific job : Tissues - a collections of cells working together to perform a specific job Made up of cells that are similar in structure and function and which work together to perform a specific activity
Examples - blood, nervous, bone, etc. Humans have 4 basic tissues: connective, epithelial, muscle, and nerve.
epithelial, connective Slide 8: Organs
Made up of tissues that work together to perform a specific activity
Examples - heart, brain, skin, etc.
Groups of two or more tissues that work together to perform a specific function for the organism.
Examples - circulatory system, nervous system, skeletal system, etc.
The Human body has 11 organ systems - circulatory, digestive, endocrine, excretory (urinary), immune(lymphatic), integumentary, muscular, nervous, reproductive, respiratory, and skeletal. Slide 9: Organisms
Entire living things that can carry out all
basic life processes. Meaning they can take
in materials, release energy from food,
release wastes, grow, respond to the
environment, and reproduce.
Usually made up of organ systems, but an organism may be made up of only one cell such as bacteria or protist.
Examples - bacteria, amoeba, mushroom, sunflower, human
The levels of organization in the correct order then are:
cells --> tissues --> organs --> organ systems --> organisms Slide 11: STRUCTURE ANALYSIS - Comparing component parts with the larger system(s) they are a part of.
You just got done learning that the levels of organization are:
cells --> tissues --> organs --> organ systems --> organism
Two human examples are:
neurons (nerve cells) --> nervous tissue --> brain --> central nervous system --> human
bone cells (osteoblasts) --> connective (bone) tissue --> bones --> skeletal system --> vertebrate