Cells & Organelles
What is an organelle?
Organelles are specialized, membrane-bound compartments or structures within a cell that perform specific jobs
What is diffusion?
The movement of particles from a crowded area to an area where they are less concentrated.
This is driven by random motion until equilibrium (even distribution) is reached, explaining how smells spread or oxygen moves in the body.
What is an ecosystem?
An ecosystem is a community of living things, like plants, animals, and even tiny bacteria, interacting with each other and their non-living environment, such as the sun, water, and soil.
What is a food chain?
A food chain shows how energy moves from one organism to another.
What are the 3 facets of the cell theory?
-All living things are made up of cells
-Cells are the basic units of all life
-All cells come from pre-existing cells
What is Osmosis?
Osmosis is the movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration. This process continues until the concentration of solutes is equal on both sides of the membrane, helping to balance things out.
It's a vital process for life, enabling plants to absorb water and helping organisms maintain fluid balance.
Plants: Root hairs absorb water from soil; wilting when soil is dry, turgidity when watered.
Producers create their own food using energy from the sun or chemicals, while consumers obtain energy by eating other organisms.
What does the energy transfer look like in a food chain (who eats who)?
Producers are eaten by herbivores (primary consumers) which are eaten by carnivores (secondary consumers) which are eventually broken down by decomposers.
What organelles can only be found in plant cells?
Organelles found only in plant cells are the cell wall, chloroplasts, and a large central vacuole.
How are diffusion and osmosis vital for cell survival?
Diffusion: cells get the oxygen and nutrients they need and remove waste.
Osmosis: balances water content inside cells to stop them from swelling or shrinking.
Essentially - these processes ensure that cells function correctly to keep an organism healthy.
List 3 abiotic factors...
sunlight, water, temperature, soil, air, humidity, pH, and salinity
How can the food chain become altered?
Major disruptions that "break" a food chain can occur because of:
-invasive species
-pollution
-climate change
-habitat loss (deforestation)
-disease
-removing key species (like predators or pollinators)
What are the differences between unicellular and multicellular organisms?
The main difference is that unicellular organisms are single-celled, with one cell performing all life functions, while multicellular organisms are made of many cells that work together and have specialized roles.
This leads to multicellular organisms having more complex structures and a division of labor, while unicellular organisms are simpler and more self-sufficient at the cellular level.
How are cells organized?
Cells to tissues, tissues to organs, organs to organ systems, and organ systems to organisms.
Levels of Organization
How do biotic and abiotic factors interact?
-Plants need sunlight, soil, and water to grow.
-Animals need water, air, and food to survive.
-Microorganisms decompose dead plants and animals to return nutrients to the soil.
Explain the nitrogen, carbon, or water cycle?
The nitrogen cycle is Earth's way of recycling nitrogen, moving it from the air to soil, living things, and back, involving key steps: Fixation, Nitrification, Assimilation, Ammonification, and Denitrification.
The carbon cycle is the natural process by which carbon atoms move between the atmosphere, oceans, and living organisms through both fast biological processes like photosynthesis and respiration, and slower geological processes like rock weathering and fossil fuel formation. This cycle is essential for life on Earth, but human activities, primarily burning fossil fuels, are releasing excess carbon into the atmosphere at a rate that disrupts the natural balance, contributing to climate change.
The water cycle is the continuous process where water moves through evaporation, condensation, and precipitation, powered by the sun and gravity. Water evaporates from oceans, lakes, and rivers into the atmosphere, where it cools and condenses to form clouds. When clouds become saturated, water falls back to Earth as precipitation (rain, snow, sleet, or hail). This water then collects in bodies of water or soaks into the ground, and the cycle repeats.
What is the major difference between prokaryotic and eukaryotic cells?
The main difference is that eukaryotic cells have a membrane-bound nucleus and other organelles, while prokaryotic cells lack a nucleus and membrane-bound organelles. This makes eukaryotic cells generally larger and more complex, found in plants, animals, fungi, and protists, while prokaryotic cells are simpler and smaller, found in bacteria and archaea.
Explain how organs work together in the circulatory system.
The heart, blood vessels, and blood work together to transport nutrients and oxygen throughout the body.
Choose biotic or abiotic...
...explain how one or the other limits organisms.
Biotic Factors (Living)
These are limits from other living things or their interactions:
Abiotic Factors (Non-living)
These are physical and chemical conditions that set boundaries for life:
How does matter cycling promote sustainability?
Matter cycling promotes environmental sustainability by conserving finite resources and ensuring essential nutrients are available for life.
Key ways matter cycling promotes sustainability: