Energy in Ecosystems (LS2.2)
Only about __% of energy transfers to the next trophic level.
What is 10%?
These are the monomers of proteins.
What are amino acids?
State the equation for photosynthesis.
6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
What is produced at the end of mitosis?
Two genetically identical diploid daughter cells.
Neurons that carry information to the brain are called ____.
What are sensory neurons?
Define altruism in animal behavior.
When an individual sacrifices or risks itself to benefit the group.
This type of ecological pyramid shows available energy decreasing at each trophic level.
What is an energy pyramid?
Which macromolecule is primarily responsible for long-term energy storage in organisms?
Lipids
Name the organelle where cellular respiration occurs aerobically.
What is the mitochondrion?
During which phase do sister chromatids separate?
What is anaphase?
What structure sends signals across synapses?
Axon terminals releasing neurotransmitters.
Give one example of group behavior that increases survival.
Herding, flocking, hunting in packs, sentinel behavior.
Explain why higher trophic levels have fewer organisms.
Because energy is lost as heat and used for life functions, leaving less energy to support higher levels.
Explain why organisms must break down food into monomers.
So matter can be recombined into the macromolecules needed for cell structure and function.
Compare ATP yield in aerobic vs. anaerobic respiration.
Aerobic: ~36–38 ATP; Anaerobic: 2 ATP.
Explain why DNA condenses into chromosomes before division.
To protect DNA and ensure equal distribution between daughter cells.
Explain how the brain integrates sensory input to produce a response.
Interneurons process signals and send commands via motor neurons to effectors.
Explain why warning calls are costly for individuals.
They reveal the caller’s location but protect the group.
Calculate: If producers contain 15,000 kcal, how much energy reaches secondary consumers?
150 kcal.
Why do different proteins have different shapes and functions even though they are all made of amino acids?
Because the order of amino acids and the unique R-groups cause proteins to fold into specific shapes, determining their function.
What is the main purpose of photosynthesis?
To convert light energy into stored chemical energy in glucose.
Define cell differentiation.
The process where cells become specialized by turning certain genes on or off.
Give an example of a negative feedback loop.
Body temperature regulation or blood glucose regulation.
What determines whether a group persists over time?
Benefits of membership must outweigh costs.
Why ecosystems require a constant input of energy (sunlight or inorganic compounds).
Because energy is not recycled—only matter is—so ecosystems must continuously receive new energy.
Explain how the law of conservation of matter relates to digestion.
Matter isn’t created or destroyed—atoms from food are reorganized into new biomolecules.
Describe how the light-dependent and light-independent reactions work together.
Light-dependent reactions make ATP & NADPH; these power the Calvin cycle to build glucose from CO₂.
Provide one structural difference between plant and animal cytokinesis.
Plants form a cell plate; animals form a cleavage furrow.
Why repeated stimuli strengthen neural pathways?
Increased use reinforces synaptic connections, making responses faster and more automatic.
How does group behavior influence evolution?
Genes supporting social behaviors are selected for when they increase survival and reproductive success.