Comparing Anatomy

Life is life is life…

Living things share common needs for food, cellular waste disposal, exchange of gasses, and means of reproduction.

the cell is the basic unit life. It is the smallest and simplest part of living matter that can carry on all the activities necessary for life.

Single celled life forms have to take care of all those processes all by themselves, on a very small scale.

Their mitochondria provide energy, gained from the environment either through photosynthesis or respiration, to run the entire cell.

Their cytoskeletons provide internal support, their nucleus coordinates the activities, etc.

In most multicellular organisms, cells associate to form tissues, such as muscle tissue or nervous tissue.

Tissues are arranged into functional structures called organs, such as the heart or stomach.

Organs then work within systems, making up the whole of the organism.

It is the ability of the cells to specialize that allows multicellular organisms to do many different functions.

Different organisms have evolved different ways of accomplishing the same thing:

(have structural designs that serve the same purpose in terms of systems such as digestion, skeletal, respiration, reproduction, and excretion)

Natural Selection, over time, provided strategies to accomplish the same result:

Ex) Gills & Lungs & Membranes all exchange O2 & CO2 between the organism

and the environment

Natural Selection, over time, provided strategies to accomplish the same result: Ex) Earthworms have a system of tubes (called

Malpighian tubes) that get rid nitrogenous waste, Whereas mammals have organs called

kidneys that filter nitrogenous waste from the blood.

Natural Selection, over time, provided strategies to accomplish the same result:

Ex) Insects have an exoskeleton made of chitin to structurally support the organism,

Whereas an elephant has an endoskeleton made of bone that does the same job.

Natural Selection, over time, provided strategies to accomplish the same result:

Ex) Plants exchange gametes through pollen and fertilized ovaries that then become fruit,

Whereas most animals exchange gametes (egg and sperm) to form new offspring.

Natural Selection, over time, provided strategies to accomplish the same result: Ex) Butterflies evolved exoskeletal extensions

such as wings that allowed them to fly Whereas birds evolved skin, skeletal, and

muscular changes resulting in winged flight.

Plants and Animals both take in energy----- Plants take in sunlight energy and Animals take

in energy in the form of food. Plants need to have both chloroplasts to convert

sunlight into food energy and mitochondria to then convert the food energy into usable ATP.

Animals have only mitochondria to convert their food into ATP.

Single celled organisms can rid themselves of waste by simply diffusing it out into their environment.

Mutlticellular organisms have specialized tissues or organs that process and then excrete waste.

Cellular function is similar in all living things. Evolution has led to the dizzying array of

specialized life forms that we see around us every day!