CELLS
What are the three main parts of a cell?
Cell membrane, cytoplasm, and nucleus
What is the difference between asexual and sexual reproduction?
Asexual: one parent, identical offspring; Sexual: two parents, genetically different offspring
What is the difference between biotic and abiotic factors in an ecosystem?
Biotic: living things (animals, plants, bacteria); Abiotic: non-living things (sunlight, water, soil, temperature)
What are the three states of matter and one property of each?
Solid (fixed shape), Liquid (takes container shape), Gas (takes container shape and volume)
What are the two most abundant gases in Earth's atmosphere?
Nitrogen (~78%) and Oxygen (~21%)
Which organelle is responsible for producing energy in the cell?
Mitochondria (powerhouse of the cell)
Define a dominant allele
An allele that is always expressed when present; it masks the recessive allele
Name a producer, a consumer, and a decomposer.
Producer: plant (grass, tree); Consumer: animal (rabbit, deer); Decomposer: fungus (mushroom) or bacteria
What is the Law of Conservation of Mass?
Matter cannot be created or destroyed; total mass of reactants equals total mass of products in a chemical reaction
What is the greenhouse effect?
Gases in the atmosphere trap heat from the sun, causing Earth's temperature to rise
Name two organelles found in plant cells but NOT in animal cells.
Cell wall and chloroplast (or large vacuole)
If both parents are heterozygous for a trait, what percentage of offspring will be homozygous recessive?
25% (or 1 in 4)
Explain how energy flows through a food chain.
Energy from the sun is captured by producers (plants), then passed to consumers (herbivores, then carnivores), with energy lost at each level
How does temperature affect particle motion?
Higher temperature = faster particle motion; Lower temperature = slower particle motion
Name two ways human activity contributes to climate change
Burning fossil fuels (releases CO₂), deforestation (removes CO₂-absorbing trees), industrial pollution, vehicle emissions
What is the function of the ribosome?
Protein synthesis (making proteins)
What is a mutation, and give one example of a beneficial mutation.
A change in DNA; Example: Antibiotic resistance in bacteria, darker skin in sunny climates, or sickle cell trait in malaria regions
Describe the water cycle in 3-4 steps.
Evaporation (water rises) → Condensation (forms clouds) → Precipitation (rain/snow) → Collection (in oceans/lakes/groundwater)
Describe the relationship between photosynthesis and cellular respiration.
They are opposite processes. Photosynthesis produces glucose and oxygen; Cellular respiration uses glucose and oxygen to produce energy (ATP).
How does the carbon cycle work? Explain in 3-4 steps.
CO₂ in atmosphere → plants absorb (photosynthesis) → animals eat plants → respiration returns CO₂ to atmosphere; decomposers also release CO₂
Explain the relationship between cell structure and function. Give one example
A cell's structure allows it to perform its function. Example: Mitochondria has many folds to increase surface area for energy production.
Explain how DNA determines traits in an organism.
DNA contains genes that code for proteins, which determine traits. Genes are inherited from parents and control physical characteristics and some behaviors.
How do invasive species affect an ecosystem?
Invasive species compete with native species for resources, reduce biodiversity, and can cause native species to decline or go extinct
Explain why a chemical reaction is considered exothermic or endothermic. Give one example of each.
Exothermic releases energy (combustion, burning wood); Endothermic absorbs energy (melting ice, photosynthesis)
Propose an engineering solution to reduce plastic pollution. Describe the criteria and constraints
Accept any realistic solution with identified criteria (what it should accomplish) and constraints (cost, materials, time, environmental impact)