Big Idea 4

1) Altruistic Behavior:  Altruistic behavior reduces an animal's individual fitness but increases the fitness of other individuals in the population.  One animal is benefiting while the other animal is sacrificing itself or sacrificing a physical item, such as food.  Such actions may be done by sharing food, making a call in warning of a predator, or helping injured animals.  This picture shows a lemur cleaning another lemur of the parasites on its fur.  This can also be referred to reciprocal altruism because once the lemur is done cleaning the other lemur, they will reverse their positions. 

2) Biological Magnification:  Biological Magnification occurs when toxins, such as insecticides and mercury, are concentrated in trophic levels of a food web.  Once the toxin is introduced at the bottom of the food web, the toxin will spread throughout the trophic levels.  First consumers eat the plants and second consumers eat the first consumers.  This picture shows an insecticide in the grass, which might be passed on through a food web. 

5) Commensalism:  Commensalism is the relationship between two organisms when one organism benefits and the other organism does not benefit or harmed.  An example would be a Vesper Sparrow in a tree.  The sparrow is benefiting because the tree provides shelter.  The tree is neither benefitting nor harmed from the sparrow.  

7) Detritovore:  A detritovore is an organism that gets its energy and nutrients from nonliving organic waste, such as decomposed plants, animal feces, and corpses.  Detritovores include millipedes, woodlice, dung flies, slugs, and earthworms.  Detritovores often function as decomposers and can be referred as the recyclers in an ecosystem because organic waste can only be eaten by detritovores.  Consumers eat detritovores.  Therefore, detritovores play a crucial role in the energy flow of a food web.  This pill bug is an example of a detritovore.

8) Endosperm:  Endosperm is tissue in angiosperm seeds that contain starch and other nutrients that feed and nourish the embryo.  An endosperm is made when two sperm nuclei join with the embryo sac or the female gametophyte.  One sperm fertilizes the egg to form a zygote while the other sperm fuses with the two nuclei in the embryo sac to form an endosperm cell.  The inside white part of a coconut is an example of cellular endosperm.  Cellular endosperm formation occurs when the cell wall forms at the same time as the division of the nuclei.  

9) Introduced Species:  An introduced species is a species that has been moved from its native location by humans.  Introduced species are also called non-native or exotic species that may have been moved intentionally or accidentally.  An example of an introduced species is this plant, Echeveria Elegans.  This species is native in desert environments.  

10) Keystone Species:  A keystone species shows strong control over their community and are crucial to the way other species survive.  Without the keystone species, a community would change severely.  A lion is an example of a keystone species because lions are predators and are always looking for food.  Lions affect the community based on what the they eat and where they live.

  

13) Niche:  A niche is an area where an organism lives.  Niche can also be referred to as an organism’s ecological role or how it fits into an ecosystem.  The way an organism uses its resources in the environment determines its ecological role.   These two orangutans live in a habitat of trees and plants.  Orangutans are omnivores, eating both meat and plants.  Also, orangutans mostly eat plants and fruit to survive.

14) Parasitism:  Parasitism occurs when one organism, the parasite, feeds and benefits from another organism, the host.  The parasite may live inside or outside of the organism it is feeding on.  Some common internal parasites include tapeworms, roundworms, and hookworms.  Some common external parasites include fleas, ticks, and mosquitoes.  This picture shows a mosquito. 

16) Organisms on different levels of the same food chain:  A food chain is a pathway of food energy that is transferred to each trophic level.  The producers begin the food chain.  Grass is an example of a producer because it makes its own food using the sun’s energy.  Next, primary consumers eat the producers.  An example of a primary consumer is a garden slug.  Then, secondary consumers eat the primary consumers for energy.  An example of secondary consumers is a pheasant.  Pheasants eat insects.  Lastly, a tertiary consumer eats secondary consumers.  An example of a tertiary consumer is a tiger.  Tigers mainly eat larger animals than birds, but they eat smaller birds like pheasant when food is scarce.   

17) Pioneer Species:  Pioneer species are species that are first to grow in ecosystems that have been disrupted or damaged.  Also, pioneer species begin a chain of ecological succession, the replacement of a type of species in an ecosystem until a stable ecological community is formed.  An example of a pioneer species is moss.  Moss grows on rocks without soil, which may be the first species to grow on the rock.  Moss can break down the rock into soil for plants to grow and obtain nutrients. 

18) Population:  A population is a group of a single species that live in the same area.  Also, the organisms of a population only breed with each other, producing more of the same species.  An example of a population is a group of flamingos.