Science

science test

Photosynthesis equation

6CO(2) + 6H(2)O + energy -> C(6)H(12)O(6) + 6O(2)

Respiration equation

C(6)H(12)O(6) + O(2) -> CO(2) + H(2)O + energy (ATP)

Fast carbon cycle

Carbon moves through living things (plants/animals) in decades.

Slow carbon cycle

Carbon stored in rocks/fossil fuels for millions of years.

Atmosphere

Layer of gases around Earth; carbon exists here as CO(2).

Biosphere

All living things; carbon stored in organic matter.

Hydrosphere

All water on Earth; carbon dissolved in oceans as carbonic acid or carbonate ions.

Geosphere (Lithosphere)

Solid Earth (rocks, soil, fossil fuels); carbon stored long-term.

Respiration (carbon release)

Living organisms release CO(2) by breaking down glucose.

Combustion (carbon release)

Burning fossil fuels or biomass releases CO(2).

Decomposition (carbon release)

Decomposers break down dead matter, releasing CO(2).

Volcanic activity (carbon release)

Volcanoes release carbon from Earth’s interior.

Human impact on carbon cycle

Burning fossil fuels releases stored carbon -> CO(2) imbalance.

Greenhouse effect

Excess CO(2) traps heat -> global warming.

Biological nitrogen fixation

Bacteria on plant roots convert N(2) -> NH(3).

Physical nitrogen fixation

Lightning converts N(2) -> NO(3)-.

Assimilation

Plants absorb NO(3)- -> passed to animals.

Ammonification

Dead matter -> NH(3).

Nitrification

NH(3) -> NO(3)- (keeps soil fertile).

Denitrification

Bacteria return nitrogen to atmosphere as N(2).

Human impact: fertilizers

Excess nitrates -> eutrophication, biodiversity loss.

Human impact: fossil fuels

Burning -> nitrogen oxides -> acid rain.

Eutrophication

Nitrates in rivers -> algae blooms -> less oxygen for aquatic life.

Ecosystem

Community + physical environment (biotic + abiotic).

Food chain example

Grass -> grasshopper -> frog.

Food web

Interconnected food chains.

Ecological niche

Habitat, nutrition, relationships.

Levels of ecological organization

Biosphere -> Biome -> Ecosystem -> Community -> Population -> Individual.

Producer (autotroph)

Makes own food (plants).

Consumer (heterotroph)

Eats other organisms (animals).

Herbivore

Eats plants only.

Carnivore

Eats animals only.

Omnivore

Eats plants + animals.

Detritivore

Feeds on decomposing matter.

Decomposer

Breaks down dead matter (bacteria, fungi).

Competition

Organisms compete for resources.

Predator‑prey

Predator kills and eats prey.

Parasitism

Parasite benefits, host harmed.

Mutualism

Both species benefit.

Commensalism

One benefits, other unaffected.

Theory in science

Best explanation based on evidence, not a guess.

Evolution

Change in heritable traits of a population over time.

Invasive species

Species thrives without competition (e.g., lionfish).

Melanin

The chemical responsible for the color of skin, providing protection against UV light.

Ultraviolet light effect(bad)

can damage DNA and lead to cancer.

Environmental condition influence on traits

can result in changes to traits, influencing survival and reproduction.

natural selection

the process where individuals with favorable traits are more likely to survive and reproduce.

Factors that influence number of offspring produced

include environmental conditions, availability of resources, and parental investment.

Why do some organisms have variations in traits

Variations in traits arise from genetic differences and environmental influences.

Genetic diversity

allows populations to adapt to changing environments and enhances survival.

Mutation example

A mutation in the gene coding for eye color can lead to variations such as blue, brown, or green eyes.

Variation (inherited)

Comes from parents through genes/DNA.

Variation (acquired)

Comes from changes during lifetime.

Selection

The process by which the environment favors some variations over others for survival and reproduction.

Over reproduction

organisms produce more offspring than can survive.Example: sunfish produces 300 million eggs.

Adaptation

the process by which a species becomes better suited to its environment through changes over generations.

Structural adaptations

Physical traits that help an organism survive and reproduce. Example: thick fur in polar bears

Behavioral adaptations

The way an organism acts to help it survive and reproduce. Example: migration of birds

Physiological adaptations

Internal body functions that help survival or reproduction. Example: snakes producing venom

Selection for an organism

Its variations have allowed it to survive and reproduce, passing its variations to the next generation.

Selection against an organism

It does not allow it to survive or reproduce, thus not passing its variations to the next generation.