1. Section 14.2 KEY CONCEPT Organisms interact as individuals and as populations.

2. Two ways organisms interact: Competition and predation
Competition: two organisms fight for a resource.
Predation: one organism captures and eats another.
The predator population depends on the prey population for survival

3. Symbiotic Relationships: LIVING TOGETHER
(1) Mutualism: both organisms benefit
Cactus provides fruit for bat to eat.
Bat spreads cactus seeds.

4. (2) Commensalism: one organism benefits, the other is unharmed
Human Our eyelashes are home to tiny mites
that feast on oil secretions and dead skin. Without harming us, up to 20 mites may be living in one eyelash follicle.
Demodicids Eyelash mites find all they need to survive in the tiny follicles
of eyelashes. Magnified here 225 times, these creatures measure 0.4 mm in length and can be seen only with a microscope. +
Organism benefits Ø
Organism is not affected
Commensalism

5. (3) Parasitism: one organism benefits, the other is harmed_
Organism is harmed
Hornworm caterpillar
The host hornworm will eventually die as its organs are consumed
by wasp larvae.
Braconid wasp
Braconid larvae feed on their host and release themselves shortly before reaching
the pupae stage of development.
Parasitism +

6. KEY CONCEPT Biomes are land-based, communities of organisms plus climate. Biomes are identified by their abiotic factors & ecological
community .

7. Earth has six major biomes.

8. (1) Tropical rain forest biomes produce lush forests.
Source: World Meteorological Organization
(1) Tropical rain forest biomes produce lush forests.
warm temperature
abundant precipitation all year

9. (2) Grassland biomes:primary plant life is grass.
Temperate grasslands are dry and warm during the summer; snow in winter.
Tropical grasslands are warm through the year, with dry and rainy seasons.

10. (3) Desert biomes are characterized by a very arid climate.
Tucson, Arizona
Source: National Oceanic Atmospheric Administration
very little precipitation
four types: hot, semi-arid, coastal, and cold

11. (4) Temperate forest biomes have seasons.
Temperate deciduous forests have hot summers and cold winters.
Temperate rain forests have a long wet season and dry summers.

12. (5) The taiga biome is located in cooler northern climates.
Source: Environment Canada
Banff, Canada
forests
long winters and short summers
little precipitation

13. limited precipitation permafrost
Barrow, Alaska
Source: National Oceanic Atmospheric Administration
(6) The tundra biome is found in the far northern latitudes with long winters.
winter lasts 10 months
limited precipitation
permafrost

14. Polar ice caps and mountains are not considered biomes.
Polar ice caps have no soil, therefore no plant community.
The climate and organisms found on mountains change as the elevation changes.

15. Nevada has four Bioregions
Sierra Nevada
Mohave Basin & Range
Central Basin & Range
(Great Basin)
4. Northern Basin & Range
Bioregion: area that contains unique geologic, hydrologic and biological characteristics
Compared to most states Nevada ranks near the top ten in biodiversity.

16. Sierra Nevada
Mountain range bordering California
Mostly granite (igneous rock cooled slowly)
Alpine forest with several species of conifers, deer, fox, mountain lions, and jackrabbits.

17. Mojave Basin & Range
Desert that touches CA, AZ, UT, southern NV
“High Desert” (3,000-5,000 feet) 10” water
Death Valley (lowest, hottest place) is here
Joshua tree, sage, cactus, scorpions, rattlesnakes, lizards, hawks, deer, cougar

18. Central Basin & Range
Central Nevada (68% of the state)
This bioregion makes up majority of the state
Valleys = basins, Mountains = ranges
Pacific & N. American tectonic plates pulling apart here; some of thinnest crust on Earth
The shifting tectonic plates create thin crust
Wetter, cooler than Mojave
Sagebrush, salt tolerant plants, pinyon, juniper, rabbits, hares, deer, mountain lions, etc.

19. Northern Basin & Range
Northern NV into OR and UT
Volcanic plateaus
Grasslands, aspen forest
Deer, cougar, coyote, eagle, lizards, etc.

20. Nevada Bioregions