Ecosystems and Biomes
What is the primary producer in a food chain?
What are: autotrophs; organisms that create their own food, usually through photosynthesis, and are considered the base of the food chain, like plants and algae; essentially, they are the organisms that produce the energy that flows through the ecosystem by converting sunlight into usable food.
What is the main process that releases carbon dioxide into the atmosphere?
The primary process that releases carbon dioxide into the atmosphere is cellular respiration, where organisms, including plants and animals, breathe and break down glucose, releasing carbon dioxide as a byproduct. This process is naturally occurring, but human activities like burning fossil fuels significantly contribute to increased carbon dioxide levels in the atmosphere.
What is the difference between exponential growth and logistic growth?
Exponential growth describes a population increasing at a constant rate, meaning the growth rate stays the same regardless of size, resulting in a J-shaped curve on a graph, while logistic growth initially grows rapidly like exponential growth but then slows down as it approaches a carrying capacity, creating an S-shaped curve, as environmental limitations like resource scarcity come into play; essentially, exponential growth assumes unlimited resources, while logistic growth considers limited resources and a maximum population size the environment can support.
What is biodiversity and why is it important?
Biodiversity refers to the variety of all living organisms on Earth, including plants, animals, and microorganisms, across different ecosystems, and is crucial because it supports the healthy functioning of our planet by providing essential services like clean air, water, food, and regulating climate, ultimately sustaining human life and livelihoods.
What is the primary source of energy for most life on Earth?
The primary source of energy for most life on Earth is the Sun; plants use sunlight through photosynthesis to create energy which is then passed through the food chain to other organisms.
Name three major terrestrial biomes and their key characteristics.
What are:
Tropical rainforests (high rainfall, high biodiversity, warm temperatures), Savannas (grasslands with scattered trees, distinct wet and dry seasons), Subtropical deserts (extremely low precipitation, hot temperatures), Chaparral (shrubby vegetation, mild wet winters, hot dry summers), Temperate grasslands (grass-dominated, moderate temperatures, seasonal precipitation), Temperate forests (deciduous trees, moderate temperatures, distinct seasons), Boreal forests (coniferous trees, cold winters, short growing season), and Arctic tundra (extremely cold temperatures, low precipitation, permafrost, limited plant life).
Explain the role of photosynthesis in the carbon cycle.
Photosynthesis plays a crucial role in the carbon cycle by removing carbon dioxide from the atmosphere and incorporating it into plant tissues, essentially "fixing" carbon as organic compounds like glucose, which plants use for growth, thus acting as the primary mechanism for bringing carbon from the air into the biosphere.
Define the concept of carrying capacity and how it relates to population size.
"Carrying capacity" refers to the maximum population size that a given environment can sustain indefinitely, meaning the largest number of individuals of a species that can live in a particular area without depleting the available resources, like food and space, causing the population to decline; essentially, when a population reaches its carrying capacity, its growth rate slows down and stabilizes at that level.
Name three major threats to biodiversity.
The major threats to biodiversity are: habitat loss, invasive species, pollution, overexploitation, and climate change.
List three renewable energy sources and their advantages.
Renewable energy sources include solar power (energy from sunlight), wind power (energy from wind), hydropower (energy from flowing water), geothermal energy (heat from the Earth's core), biomass (energy from organic matter like plants), and tidal energy (harnessing the power of ocean tides), all offering advantages like being clean, sustainable, and producing little to no greenhouse gas emissions.
Explain the concept of a niche and how different species can occupy different niches within an ecosystem.
A "niche" in ecology refers to the specific role a species plays within its ecosystem, encompassing the environmental conditions it needs, the resources it utilizes, and its interactions with other organisms, essentially defining its "way of life" within the habitat; different species can occupy different niches within an ecosystem by specializing in different food sources, feeding times, habitat use, or other aspects of their lifestyle, minimizing competition and allowing for greater biodiversity within the same environment.
How does the burning of fossil fuels contribute to the carbon cycle imbalance?
Explain the concept of "r" and "K" selection strategies in population ecology.
In population ecology, "r" and "K" selection strategies refer to two contrasting reproductive strategies that organisms employ depending on their environment, with "r-selected" species prioritizing rapid population growth in unstable environments by producing many offspring with little parental care, while "K-selected" species focus on producing fewer, higher quality offspring with greater parental investment in stable environments, where the population is more likely to reach carrying capacity ("K").
Explain the concept of an "ecosystem service" and give an example.
An "ecosystem service" refers to the benefits that humans directly receive from natural ecosystems, such as clean air, water, food, pollination, and flood control, essentially the positive contributions that nature provides to human well-being; a prime example would be a healthy forest acting as a carbon sink, absorbing carbon dioxide from the atmosphere and mitigating climate change.
Explain the environmental impacts of coal combustion.
Coal combustion significantly impacts the environment by releasing greenhouse gases like carbon dioxide, contributing to climate change, as well as emitting pollutants like sulfur dioxide and nitrogen oxides which cause acid rain, smog, and respiratory issues, while also generating ash waste that can contaminate water sources if not properly managed; additionally, coal mining itself can disrupt ecosystems and landscapes.
Describe the process of succession in an ecosystem, including the stages involved.
Ecological succession is the process where a community of organisms in an ecosystem gradually changes over time, usually following a disturbance, progressing through stages from pioneer species to a more complex climax community, with key stages including "nudation," "invasion," "competition," "reaction," and finally, "stabilization" or "climax" where a stable community is reached; this can be further categorized into primary succession (starting from bare rock) and secondary succession (occurring in a previously disturbed area with existing soil).
Describe the process of carbon sequestration and its importance in mitigating climate change.
Carbon sequestration is the process of capturing carbon dioxide (CO2) from the atmosphere or industrial sources and storing it in a secure reservoir, like underground geological formations, to prevent it from contributing to climate change; essentially, it involves removing carbon from the air and storing it where it cannot escape back into the atmosphere, thus mitigating the greenhouse effect.
List three factors that can affect the birth rate of a population.
Three factors that can significantly affect a population's birth rate are: access to contraception, socioeconomic conditions (including economic stability and cost of raising a child), and cultural norms regarding family size and childbearing age.
What is habitat fragmentation? Give an example of how it occurs.
Bonus: What is CITES
This process occurs when populations become isolated, leading to reduced genetic diversity and increased extinction risk. examples include: Roads and Highways, Suburban Development and Agricultural Expansion.
Bonus: This international agreement aims to regulate trade in endangered species to prevent extinction.
Describe the concept of energy efficiency and how it can reduce environmental impact.
Energy efficiency means using less energy to perform the same task, essentially minimizing energy waste, which directly translates to a reduced environmental impact by lowering the amount of fossil fuels needed to generate electricity, thus reducing greenhouse gas emissions and air pollution associated with energy production.
How do limiting factors affect the carrying capacity of a population within an ecosystem?
Limiting factors directly determine the carrying capacity of a population within an ecosystem by restricting the maximum population size that can be sustained by the available resources, such as food, water, and shelter; when a population approaches the carrying capacity due to a limiting factor, the growth rate slows down as resources become scarce, preventing further population increase.
What are the potential impacts of ocean acidification on marine ecosystems?
Ocean acidification can significantly impact marine ecosystems by hindering the ability of many marine organisms, particularly those that build shells and skeletons from calcium carbonate, like corals, oysters, and plankton, to form and maintain their structures due to reduced carbonate ion availability in the water, potentially disrupting entire food webs and causing population declines across various trophic levels; this could lead to changes in species distribution, reduced biodiversity, and potential collapse of important fisheries depending on the severity of acidification.
How can human activities impact the population dynamics of a species?
Human activities can significantly impact the population dynamics of a species by altering their habitat, causing overexploitation through hunting or fishing, introducing invasive species, polluting their environment, and contributing to climate change, all of which can lead to population declines or shifts in species distribution and abundance.
Discuss the role of protected areas in biodiversity conservation.
Protected areas play a crucial role in biodiversity conservation by providing a safe space for species to live and reproduce without significant human interference, safeguarding critical habitats, maintaining natural ecological processes, and acting as a key tool to combat species extinction by preserving genetic diversity across landscapes, effectively serving as the cornerstone of biodiversity protection efforts globally.
Discuss the potential benefits and drawbacks of nuclear power generation.
Advantages: Produces no polluting gases, does not contribute to global warming, very low fuel costs, low fuel quantity reduces mining and transportation effects on environment, high technology research required benefits other industries, power station has very long lifetime.
Disadvantages: Waste is radioactive and safe disposal is very difficult and expensive. Local thermal pollution from wastewater affects marine life. Large-scale accidents can be catastrophic. Public perception of nuclear power is negative. Costs of building and safely decommissioning are very high. Cannot react quickly to changes in electricity demand.