eco

  • Abiotic factors – Nonliving parts of an ecosystem (e.g., sunlight, temperature, water, rocks).

  • Bioaccumulation – The buildup of toxic substances in an organism over time.

  • Biotic factors – Living parts of an ecosystem (e.g., plants, animals, bacteria).

  • Decomposers – Organisms like fungi and bacteria that break down dead material and recycle nutrients.

  • Food Chain – A linear sequence showing who eats whom in an ecosystem.

  • Hydrosphere – All the water on Earth, including lakes, oceans, rivers, and underground water.

  • Omnivore – An organism that eats both plants and animals.

  • Scavenger – An animal that feeds on the remains of dead animals.

B

  • Algal blooms – Rapid growth of algae in water due to excess nutrients, often harmful.

  • Biogeochemical Cycles – Natural cycles that move nutrients through the Earth's systems (e.g., water, carbon, nitrogen cycles).

  • Carnivore – An animal that eats only other animals.

  • Ecological Niche – The role or job of an organism in its ecosystem, including what it eats and how it interacts with others.

  • Food Web – A complex network of connected food chains showing how energy moves through an ecosystem.

  • Ecological Pyramids – Diagrams that show the amount of energy or organisms at each level in a food chain.

  • Pesticides – Chemicals used to kill pests (like insects or weeds) that harm crops.

  • Stewardship – Responsible management and care for the environment and natural resources.

C

  • Aquatic – Related to water; living or growing in water.

  • Biomass – The total mass of living organisms in a given area.

  • Carrying Capacity – The maximum number of organisms an environment can support without damage.

  • Ecology – The study of how organisms interact with each other and their environment.

  • Habitat – The natural home or environment of an organism.

  • Invasive Species – Non-native species that spread quickly and harm local ecosystems.

  • Photosynthesis – The process by which plants use sunlight to make food from carbon dioxide and water (glucose) THE OPPOSITE IS RESPIRATION

  • Sustainability – Using resources in a way that meets our needs without harming future generations.

D

  • Atmosphere – The layer of gases surrounding Earth, essential for life and weather.

  • Biome – A large region with a specific climate and types of plants and animals (e.g., desert, forest).

  • Cellular Respiration – The process by which cells break down sugar to release energy.

  • Ecosystem – A community of living things and their nonliving environment, interacting together.

  • Herbicide – A chemical used to kill unwanted plants (weeds).

  • Lithosphere – The solid outer layer of the Earth, including rocks and soil.

  • Primary Consumer – An organism that eats producers (plants), usually herbivores.

  • Top Carnivore – The highest predator in a food chain, with no natural predators.

E

  • Autotroph – An organism that makes its own food, usually through photosynthesis (e.g., plants).

  • Biosphere – All areas on Earth where life exists, including land, water, and air.

  • Consumer – An organism that eats other organisms for energy.

  • Eutrophic – Water bodies rich in nutrients, often leading to too much algae and low oxygen levels.

  • Heterotroph – An organism that gets its food by eating others (cannot make its own food).

  • Oligotrophic – Water bodies that are low in nutrients and have clear water and high oxygen.

  • Producer – An organism that makes its own food, such as plants or algae.

  • Trophic Levels – The levels in a food chain showing energy flow, from producers up to top consumers.

  • Species- organisms that can reproduce


  • Biodiversity - Encompasses the variety of life on Earth, from the genetic diversity within a species to the different species themselves and the ecosystems they inhabit. 

    • Biodiversity is crucial for healthy ecosystems because it enhances stability, resilience, and the provision of vital services.





  • Key Elements of a Food Chain:

  • Producers:
    Organisms like plants, which can produce their food through photosynthesis, form the base of the food chain. 

  • Consumers:
    - Primary consumers are herbivores that eat producers (like plants), secondary consumers are carnivores that eat primary consumers, and tertiary consumers eat secondary consumers. 

  • - Organisms that eat other organisms for energy, including herbivores (eating plants), primary consumers, carnivores (eating other animals), and omnivores (eating both plants and animals). 

  • Decomposers:
    Organisms like bacteria and fungi that break down dead organic matter, recycling nutrients back into the environment. 

  • Trophic Levels:
    Each position in a food chain, representing the level of feeding relationships/energys. 

  • Example Food Chain:

  • Grass (producer) -> Grasshopper (herbivore) (Heterotroph)  -> Bird (carnivore) -> Snake (carnivore) -> Owl (carnivore) 

  • 10% of energy is being transferred between levels 

  • The food chain can't be more than seven levels tall

  • The bottom has the most energy

  • The arrows represent the transfer of energy 


They don't only have one source of energy

Trophic levels and Photosynthesis:

  • As you go higher in the levels, around 90% of energy is lost, only 10% is transferred

  • The amount of apex predators in the highest level is much lower than the amount of producers, due to balance needed in the food chain

  • Photosynthesis : Energy + CO2 + H2O →C4H12O6 + O2

  • Reverse of the formula is respiration

  • Us, as humans, and animals only carry out respiration

  • Plants are producer, photosynthetic, and humans and animals are consumers, respiration

  • Photosynthesis and respiration are complementary, and are needed


Predation:

  • Intraspecific competition is a biological interaction where individuals of the same species compete for limited resources

  • Predator-prey interactions refer to the fundamental ecological relationships between predators and their prey in aquatic environments

  • Mimicry is an evolutionary process where one organism (the mimic) develops a resemblance to another organism (the model) or object.

  • A common example of camouflage is a stick insect blending in with a branch


Symbiosis:

  • The three main types of symbiotic relationships are mutualism, commensalism, and parasitism.

    • Mutualism: In this relationship, both species involved benefit. For example, bees and flowers engage in a mutualistic relationship where the bees get nectar for food, and the flowers get pollinated, helping them reproduce. 

    • Commensalism: In this type of relationship, one species benefits, while the other is neither harmed nor helped. For example, barnacles on whales benefit by getting a free ride and access to food sources, while the whale is not affected. 

    • Parasitism: In this relationship, one species (the parasite) benefits at the expense of the other species (the host). For instance, fleas on a dog are parasites because they feed on the dog's blood and cause irritation, while the dog suffers from this interaction.

Limiting Factors:

  • Resources that can limit the growth rate 


Population Growth:

  • Under ideal conditions, populations can grow exponentially.

  • The growth rate increases as the population gets larger.

  • Most populations do not live under ideal conditions and grow logistically instead.

  • Density-dependent factors slow population growth as population size nears the carrying capacity



Symbiotic Relationships

  • Symbiosis is a close relationship between two species in which at least one species benefits.

  • Mutualism is a symbiotic relationship in which both species benefit.

    • Flowers and Bees

  • Commensalism is a symbiotic relationship in which one species benefits while the other species is not affected.

    • Barnacles and Whales

  • Parasitism is a symbiotic relationship in which one species (the parasite) benefits while the other species (the host) is harmed.

    • Fleas and Dogs

    • Tapeworms and Humans


Bioaccumulation

1. Mercury Pollution

  • Mercury is released into the atmosphere when coal is burned.

  • In the air, mercury forms droplets that settle into water or sediments.

  • In sediments, bacteria convert mercury into a highly toxic form called methyl mercury.

2. Bioaccumulation

  • Bioaccumulation is the gradual buildup of a toxic substance in an organism over its lifetime.

  • It occurs when organisms absorb a substance faster than they can get rid of it.

  • Mercury is stored in fat and stays in the organism’s body.

  • Example: A small fish eats many plankton and accumulates the mercury in them. Over time, the amount of mercury in its body increases.

3. Biomagnification (or Bioamplification)

  • Biomagnification is the increase in concentration of a substance as it moves up the food chain.

  • A predator accumulates all of the toxic substance from the prey it eats.

  • Organisms higher up in the food chain (like tuna) end up with the most mercury.

  • Humans who eat large predatory fish like tuna can also accumulate harmful levels of mercury.




4. Health Hazards

  • Methyl mercury is a neurotoxin that can damage the brain and nervous system.

  • It is especially dangerous to infants and children, causing developmental delays.

  • Pregnant women and children are advised to limit intake of large predatory fish due to the risk of mercury exposure.

  • The phrase “mad as a hatter” refers to mercury poisoning symptoms once common among hat makers who used mercury in their work.

Examples

  • Bioaccumulation: A small fish absorbs mercury from eating contaminated plankton.

  • Biomagnification: A tuna accumulates mercury from eating many small fish.

  • Human Impact: A person eating tuna regularly can accumulate mercury and may suffer health effects, especially if pregnant.

  • Historical Impact: Hat makers exposed to mercury developed neurological symptoms, leading to the term “mad as a hatter.”



Three Cycles:

PART A: THE CARBON CYCLE 

1. Why are photosynthesis and cellular respiration considered to be complementary processes? HINT Look at the chemical equations

Photosynthesis and cellular respiration are considered complementary processes because the products of one are the reactants of the other, effectively reversing the chemical reactions involved

  • Photosynthesis:
    This process takes in carbon dioxide (CO2) and water (H2O) and, using sunlight, produces glucose (C6H12O6) and oxygen (O2).

  • Cellular Respiration:
    This process takes in glucose (C6H12O6) and oxygen (O2) and converts them into carbon dioxide (CO2), water (H2O), and energy in the form of ATP. 

2. Why are decomposers important in the carbon cycle?

They break down dead organisms and waste, returning carbon to the atmosphere as carbon dioxide.

3. Explain the ways that humans impact the carbon cycle. If it has a negative impact, come up with a solution to reduce or eliminate it.

Humans impact the carbon cycle primarily through the release of excess carbon dioxide into the atmosphere, disrupting its natural balance and leading to climate change.

Humans can shift to renewable energy sources, adopt more sustainable transportation methods, and implement land management practices that promote carbon sequestration

4. Explain why carbon is cycled more slowly in cold northern ecosystems than in the hot tropics. HINT Particle theory can help you answer this question

Colder temperatures, shorter growing seasons, and higher organic matter in the soil. There is also less energy in colder temperatures, and the particles move slower.


PART : B THE NITROGEN CYCLE

1. Since Nitrogen makes up 79 % of the atmosphere, why is it so difficult for living organisms to obtain the nitrogen they need?

There's a strong triple bond between nitrogen atoms in N2 that makes it extremely unreactive, hindering its biological conversion.

Some animals also do not possess the right enzymes, (nitrogenase and more), to break the triple bond, and it makes it more difficult for them to obtain the gas.

2. How do animals obtain usable nitrogen?

Animals primarily obtain usable nitrogen by consuming plants or other animals that have already consumed plants. 

3. What would happen to animals if all of the nitrogen fixing bacteria in soil and on plant roots was killed by pesticides?

If nitrogen-fixing bacteria were killed by pesticides, a significant impact on animals would occur due to the disruption of the nitrogen cycle. Nitrogen is an essential nutrient for plant and animal life, and the loss of nitrogen-fixing bacteria would lead to reduced plant growth and lower plant yields

4. Why are legumes important in crop rotation?

Nitrogen Fixation:

Legumes have a symbiotic relationship with nitrogen-fixing bacteria (Rhizobium) in their roots. These bacteria convert atmospheric nitrogen into a form that plants can use, making it readily available for subsequent crops. 

Improved Soil Structure:

Legumes help build soil structure through their root systems, promoting better aeration, water infiltration, and root penetration for following crops. 

Increased Soil Organic Matter:

Legumes contribute to the soil's organic matter content, which improves soil fertility and helps retain moisture. 

Disease and Pest Control:

Rotating legumes with other crops can help break disease and pest cycles, reducing the risk of outbreaks in subsequent crops. 

Reduced Fertilizer Requirements:

By adding nitrogen to the soil, legumes can significantly reduce the need for synthetic fertilizers, making farming more sustainable and cost-effective. 

Erosion Control:

Legumes, especially those with strong root systems, can help prevent soil erosion by anchoring the soil particles and providing a protective cover. 


  • There would be no soil for the water to be absorbed

  • To prevent runoffs, because concrete cant abo