Unit 1: Ecosystems
Name the three types of symbiotic relationships and explain the realtion (+, -< or none?).
Parasitism (+, -)
Mutualism (+, +)
Commensalism (+, 0)
Which terrestrial biome has the highest annual precipitation?
Tropical Rainforest?
What is the difference between r-selected and K-selected reproductive strategies?
r-selected: species produce more offspring with little parental care, typically in unstable environments (ex. insects)
K-selected: species produce fewer offspring but invest more in their care typically in more stable environments (ex. elephants)
Name the 5 layers of the Earth's atmosphere in order!
Bonus +200 if you can describe something drastic about each
Exosphere (outermost layer, lack of density so cold, in outer space)
Thermosphere (few particles, highly energized by solar radiation, a sharp increase in temperature with altitude)
Mesosphere (meteors burn up this layer, temperature decreases with altitude, coldest layer)
Stratosphere (ozone, absorbs solar radiation, temperature increases with altitude due to absorption by ozone)
Troposphere (lowest, 75% of the atmospheres mass, cloudy, stormy, and rainy, temperature decreases with altitude )
What is the formula for calculating the Birth Rate percentages?
Birth rate % = (Number of Births / Total Population) x 100%
What is the difference between producers and consumers in an ecosystem?
Producers (autotrophs) make their own food through photosynthesis and chemosynthesis.
Consumers (heterotrophs) obtain energy by eating other organisms.
What are the factors that determine the species richness of an island, according to the theory of island biogeography?
Island size (larger islands support more species and have more resources)
Proximity to the mainland (closer islands have more immigration and species richness)
How do density-dependant and density-independent factors differ in their effect on population growth?
Density-dependent factors (ex. food diseases) affect a population more strongly as it becomes more crowded.
Density-independent factors (ex. weather, natural disasters) affect the population regardless of its size.
How does the distribution of solar isolation (incoming solar radiation) contribute to the Earth's climate zone?
Solar isolation (incoming solar radiation) is more direct at the equator and less direct at higher lattitudes, causing an incline of warmer temperature at the equator and cooler temperatures at the poles, which defines the Earth's climate zone.
What are the major characteristics of the tundra biome?
Cold temperatures, low precipatation, short growign seasons, premafrost, and limited plant and animal life.
What are the four zones of lakes and ponds in freshwater biomes?
Littoral zone (near shore)
Limnetic zone (open water)
Profundal zone (deep water)
Benthic zone (bottom)
Describe the process of ecological succession. What is the difference between primary and secondary succession?
Ecological succession is the predictable process of species replacement in an ecosystem.
Primary succession occurs in an area without soil (ex. after a volcanic eruption)
Secondary succession occurs in an area with pre-existing soil (ex. after a forest fire)
How do human demographic factors (like access to healthcare, education, and sanitation) influence population growth rates in developing countries?
Better healthcare, education, and sanitation lead to lower birth and death rates, as people have better access to family planning, healthier living conditions, and longer life expectancy.
How does the Coriolis effect influence wind patterns?
The Coriolis effect causes moving air to be deflected due to Earth's rotation: winds are deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, creating prevailing wind patterns.
Explain the relationship between carrying capacity and logistic growth.
In logistic growth, population growth slows as it approaches the environment's carrying capacity, the maximum population size that the environment can support.
Describe the process of Nitrogen Fixation:
When Nitrogen gas in the atmosphere is converted into ammonia or ammonium by bacteria in the soil or in roots.
How would an episodic disturbance, such as a volcanic eruption, impact species richness and community composition in the affected area? Compare this to the impact of a periodic disturbance like a forest fire.
An episodic disturbance can drastically reduce species richness and alter community composition by wiping out most life and leaving the area bare. Recovery is slow, as primary succession begins with pioneer species colonizing the area. A periodic disturbance like a forest fire often results in less severe loss of species richness, as some species may survive in the soil or as seeds. Recovery through secondary succession is faster, and the community composition can quickly rebound with a mix of species.
What is the difference between J-curve and an S-curve in population growth models?
J-curve represents exponential growth, where the population grows rapidly without resource limitations.
S-curve represents logistic growth, where the population grows rapidly but eventually levels off at the carrying capacity.
What is the impact of El Nino and La Nina on global weather patterns?
El Nino causes warming of the Pacific Ocean, leading to altered precipitation patterns, reduced upwelling, and extreme weather events like droughts and floods.
La Nina causes cooler-than-normal ocean temperatures, with opposite weather patterns to El Nino, such as increased hurricanes and stronger upwelling.
How do trophic pyramids and the 10% Rule impact the energy flow in ecosystems?
Trophic pyramids show how energy decreases at each trophic level, with only about 10% of energy passed on to the next level, explaining the structure of food webs.
What are the differences between the processes of nitrification and denitrification in the nitrogen cycle?
Nitrification is the conversion of ammonia to nitrites and then to nitrates by bacteria.
Denitrification is the conversion of nitrates back to nitrogen gas by bacteria completing the cycle.
Define ecological tolerance and describe how it relates to a species’ fundamental and realized niches.
Ecological tolerance is the range of environmental conditions (such as temperature, moisture, or pH) that a species can survive, grow, and reproduce within. The fundamental niche is the full range of conditions a species could occupy without competition or other constraints. The realized niche is the actual range of conditions the species occupies, influenced by biotic factors like competition and predation.
How do the reproductive strategies of species with Type I and Type III survivorship curves differ, and how might an increase in predation affect their population dynamics?
Species with a Type I survivorship curve, like humans, invest heavily in fewer offspring, ensuring higher survival rates through parental care. Species with a Type III curve, like many fish, produce many offspring with little parental care, expecting high mortality early in life. An increase in predation would likely bring down survival in Type III species, potentially leading to population decline, while Type I species may be more resilient due to their parental investment and lower juvenile mortality.
What is soil erosion, and how does it impact agriculture and the environment?
Soil erosion is the removal of the topsoil layer by wind, water, of human activities. It reduces soil fertility, harms plant growth, and leads to sedimentation in rivers, which affects aquatic ecosystems aswell.
How can a country in Stage 2 of the Demographic Transition Model experience a population explosion while simultaneously facing increased pressure on its natural resources? Provide an example of a country currently in Stage 2, and explain how both birth rates and death rates influence the transition.
This country has high birth rates and declining death rates due to improved healthcare and sanitation, leading to a population explosion. The high birth rates are due to cultural, social, or economic factors, while the declining death rates result from reduced infant mortality and longer life expectancy. Rapid population growth in Stage 2 places significant pressure on natural resources, as the demand for food, water, and land increases faster than the country's ability to provide for its growing population.