HOW POPULATIONS SURVIVE Unit B Lesson 4

WHAT CONTROLS THE THE GROWTH OF POPULATION?  Limiting Factor- Anything that controls the growth or survival of a population.  Some limiting factors are non-living such as sunlight, water, wind, and temperature.  Living limiting factors include grasses, insects, and animals.

WHAT IS COMPETITION?? GIVE AN EXAMPLE!

COMPETITION  Animals compete with one another for food water and shelter.  Some animals eventually will die and soon there will be enough resources for the organisms that remain.

IMAGINE  Living in a hot desert such as the Sonoran Desert. What could you do to survive ?

HOW DO PLANTS ADAPT TO HARSH ENVIRONMENTS?  Plants are almost everywhere on earth!  They can survive because they have developed special characteristics.  ADAPTATIONS- Characteristice that help an organism survive in its environment.  Adaptations are INHERITED traits, they are not learned behaviors.  Barrel Cactus- Sonoran Desert (CA)  It is well adapted to desert conditions.

Barrel Cactus  Very shallow roots and only grow about 7.5 cm into the dry soil  The soak up the little rain that falls quickly.  During long dry spells the fine ends of the roots fall off. This allows the stored water to become sealed inside the plant.  The stem is covered with needle sharp spines. These stems protect “folds” or moist sections from the dry winds.  They also keep away bird sand small animals from taking the water.

SYMBIOSIS

 THE RELATIONSHIPS BETWEEN 2 ORGANISMS THAT LASTS OVER A PERIOD OF TIME. 1. Mutualism 2. Parasitism 3. Commensalism

MUTUALISM  WHEN A RELATIONSHIP BETWEEN TWO KINDS OF ORGANISMS BENEFITS BOTH OF THEM  Yucca Moth and Yucca Tree  The moths cannot survive without the Yucca tree.  The tree would also become extinct without the moths.  The moth pollinates the tree by rolling pollen into a ball and transferring it to another flower on the Yucca Tree.

PARASITISM  THE RELATIONSHIP IN WHICH ONE ORGANISM LIVES ON OR IN ANOTHER ORGANISM AND MAY HARM IT.  Parasites- are the organisms that live off of another living thing.  Hosts- are the organisms that parasites feed off of.  Examples: 1. Fleas. 2. Coiling dodder plant, 3. Mistletoe

COMMENSALISM 

COMMENSALISM  RELATIONSHIP WHERE ONE BEBEFITS FROM ANOTHER WITHOUT HARMING IT.  Orchids attach themselves to a tree, but make their own food so it does not harm the tree.  What does NEMO and Marlin live in?  Anemone! Clown fish an other tropical fish can live in an anenomes harmful tentacles without being harmed.

HOW DO POPULATIONS SURVIVE EARTH’S CHANGES.  Earth is constantly changing  18,000 years ago Earth was a cold place covered in large sheets of ice.  Slowly Earth began to warm up and the ice melted and sea level rose.  Continents also moved, large rocks have crashed to the earth, volcanoes have poured gas into the air.  Some organisms survived, others did not.  Those that did not survive became EXTINCT.  Example: Dinosaurs. There are many theories as to how dinosaurs have become extinct. 

SUM IT UP!  Write 3 facts!  Write 3 really interesting things you learned (different from the facts)  Quick Summary!  Are you test ready?