Structures & Functions of Living Organisms

Living Organisms What do you think is the largest living organism? What do you think is the smallest living organism? Make a list in your notebook of 5 of the largest and 5 of the smallest living things that you can think of.

What really is the smallest organism?

Single Celled Organisms What characteristics do single celled (unicellular) organisms have in common?

Single Celled Organisms How do unicellular organisms differ from one another?

Single Celled Organisms What characteristics do unicellular organisms such as the ones you have just seen share with multicellular organisms such as birds, dogs, or humans?

Single Celled Organisms How do these unicellular organisms get nourishment, water, and oxygen and get rid of waste?

Single Celled Organisms How do unicellular organisms move?

Single Celled Organisms How do unicellular organisms reproduce?

Single Celled Organisms A CELL is the basic unit of life. These single celled organisms are classified as PROTISTS. Protists are unicellular EUKARYOTIC organisms. Eukaryotic means cells that have membrane bound organelles. The organism’s DNA is found inside a nucleus.

Types of Single Celled Organisms There are 3 major classes of Protists: Animal-like protists Plant-like protists Fungus-like protists

Animal-like Protists The PARAMECIUM is animal-like It has short hair-like structures, called CILIA, that beat rapidly to move the paramecium along.

Animal-like Protists The AMOEBA is animal-like It moves and eats by extending it’s false foot to surround it’s food.

Plant-like Protists The EUGLENA is plant-like. It has CHLOROPLASTS which allow it to make it’s own food. The process of making it’s own food is called PHOTOSYNTHESIS A euglena moves by whipping it’s FLAGELLUM around.

This is a picture of a Euglena

Plant-like Protists The VOLVOX is plant-like. It is a type of green algae that can be found in groups called colonies. Usually found in fresh water.

Lots of Organelles! Organelles are like little organs for the cell, carrying out specific jobs for the cell to function properly. Cell membrane: semi-permeable membrane that holds the cell together and allows gases to pass through it. Cytoplasm: the liquid inside the cell Contractile vacuole: moves water in and out of the cell Food vacuole: where food is digested Nucleus: where DNA is stored Pseudopod: a “false foot” used for movement

Lots of Organelles! Chloroplast: where photosynthesis occurs Gullet & Mouth Pore: mouth-like area that takes in food Eyespot: used to detect light for plant-like protists Flagellum: whip-like tail used for locomotion Cilia: hair-like structures along the outside of the cell used for locomotion Oral groove: pushes food into a food vacuole for digestion Anal pore: passes waste out of the cell

How can we see these things? These organisms are MICROSCOPIC. We need to use a microscope in order to see them. Do you remember how to use a microscope??

TIME TO PRACTICE! Now it’s your turn to practice your microscope skills! Make sure to follow ALL directions on the lab sheet.