Glossary
Autotrophs
Organisms that produce their own organic compounds (food) from simple inorganic substances, usually using light or chemical energy.
Example:
Cyanobacteria in the ocean are autotrophs, performing photosynthesis to create their own food and contributing significantly to global oxygen production.
Biodiversity
The variety of life in a particular habitat or ecosystem, encompassing the diversity of genes, species, and ecosystems.
Example:
The Amazon rainforest is renowned for its immense biodiversity, hosting millions of species of plants, animals, and microorganisms.
Ectotherms
Organisms whose body temperature largely depends on external environmental sources, often regulating it through behavioral adaptations.
Example:
A lizard basking on a warm rock is an ectotherm, absorbing heat from its surroundings to raise its body temperature for optimal activity.
Endotherms
Organisms that maintain a relatively constant internal body temperature largely independent of the external environment, primarily through metabolic processes.
Example:
A human shivering in the cold is an endotherm, using muscle contractions to generate heat and keep their core body temperature stable.
Energy Availability
The total amount of usable energy present within an ecosystem, primarily determined by the productivity of its producers.
Example:
A lush rainforest has high energy availability due to abundant sunlight and water, supporting a vast array of plant and animal life.
Energy Flow
The unidirectional movement of energy through an ecosystem, typically starting from the sun, moving to producers, and then to various levels of consumers.
Example:
The energy flow in a grassland ecosystem begins with sunlight captured by grasses, then moves to grazing zebras, and finally to the lions that prey on the zebras.
Heterotrophs
Organisms that obtain energy and nutrients by consuming other organisms or organic matter.
Example:
A hungry wolf is a heterotroph, relying on hunting deer to get the energy it needs to survive and reproduce.
Hibernation
A state of minimal activity and metabolic depression in endotherms, characterized by reduced body temperature, slower breathing, and lower metabolic rate, typically during winter.
Example:
A groundhog entering hibernation in its burrow will drastically lower its heart rate and body temperature to conserve energy throughout the cold months.
K-selected species
Species characterized by slow reproduction, producing few, larger offspring, and investing significant parental care, typically found in stable environments near carrying capacity.
Example:
An elephant is a K-selected species, giving birth to a single calf after a long gestation and investing years in its upbringing and protection.
Metabolic Rate
The rate at which an organism converts chemical energy from food into other forms of energy, including heat and energy for cellular processes.
Example:
A hummingbird has an incredibly high metabolic rate, burning through energy rapidly to power its constant wing movements and maintain its tiny body temperature.
Net Gain (Energy Balance)
A state where an organism consumes more energy than it expends, leading to energy storage, growth, or reproduction.
Example:
After a successful hunt, a bear experiences a net gain of energy, allowing it to build up fat reserves for hibernation.
Net Loss (Energy Balance)
A state where an organism expends more energy than it consumes, resulting in a decrease in mass and potentially leading to starvation or death.
Example:
During a harsh winter with scarce food, a deer might experience a net loss of energy, causing it to lose weight and become more vulnerable.
Photosynthesis
The process by which photosynthetic organisms convert light energy into chemical energy, typically in the form of glucose.
Example:
A towering redwood tree uses photosynthesis to transform sunlight, water, and carbon dioxide into the sugars it needs to grow, forming the base of its forest ecosystem's energy.
Species Distribution
The geographical area where a particular species can be found, influenced by environmental factors and resource availability.
Example:
The species distribution of polar bears is limited to Arctic regions because they are adapted to cold climates and rely on sea ice for hunting seals.
Thermoregulation
The process by which an organism maintains its internal body temperature within a narrow optimal range, despite fluctuations in external temperature.
Example:
When a dog pants on a hot day, it's engaging in thermoregulation to cool down by evaporating water from its tongue and respiratory tract.
Trophic Level
An organism's specific position in a food chain or food web, indicating its primary source of energy.
Example:
In a pond ecosystem, algae occupy the first trophic level as producers, while small fish eating the algae are at the second trophic level.
r-selected species
Species characterized by rapid reproduction, producing many small offspring, and providing minimal parental care, often thriving in unstable or unpredictable environments.
Example:
A dandelion is an r-selected species, producing thousands of tiny seeds that disperse widely, hoping a few will land in a suitable spot to grow.