Ecology EX1

hypothesis

An idea that potentially explains a repeated observation

theory

An explanation of a wide range of natural phenomena that has been repeatedly tested

law

Statement or equation based on a natural phenomena to predict the results of that phenomenon

what is the difference between a theory and a law?

theory explains “why” and law explains “how”

Manipulative experiments

Hypothesis is tested by directly altering a factor thought to be causing the hypothesis

treatment groups

Group that includes the factor we are altering

control group

Includes all aspects of an experiment except the factor of interest

observational study

Draws inferences from natural changes in a population, community, or ecosystem, performed for ethical reasons

What is the difference between statistical and mathematical models?

statistical contains varied data points while mathematical is theoretical based on an equation

models

Represent the real world, hypothesized relationships based on theory

What are the levels of ecological hierarchy?

Organism → Population → Community → Ecosystem → Landscape → Biome → Biosphere

What is fitness?

how well an organism can survive and reproduce in its environment

What is a population

group of individuals within a species that interact

What is a species

group of organisms that naturally interbreed and produce fertile offspring

What is a community

all species populations within a given area

What is an ecosystem

consistent community and nonliving environment

What is landscape ecology

study of interactions between ecosystems in an area

What is a biome

regional area with similar vegetation types

What is biome and biosphere ecology

exchange of organisms energy and matter across ecosystems and biomes

What is a niche

organism's role and fit in an ecosystem, based on abiotic and biotic tolerances

What are abiotic tolerances

organism's ability to survive despite variation on nonliving environmental factors

What are biotic tolerances

how an organism responds to the presence and influence of other living organisms

Organisms can be identified according to

Species identity• Energy source• Dominant interaction• Where it lives• What it does

What is a mixotroph

derives energy from both auto and heterotrophic nutrition

What is predation?

A species interaction where one benefits and the other is harmed.

What is mutualism?

A species interaction where both species benefit.

ex-bees and flowers

What are Scavengers

they consume dead animals

ex- vultures

What are Detritivores

they break down detritus into smaller particles of detritus

ex- earthworms

What is detritus

dead organic matter

What are Decomposers

break down detritus into basic elements that can be recycled

ex- fungi

What is amensalism?

One population is inhibited, while the other is not affected

ex- staphylocoque and penicillium

What is Neutralism

both species are unaffected, hard to show in nature

What's the difference between predation and parasitism

predation is a quick interaction, while parasitism is a prolonged relationship

what is commensalism

One species benefits, the other not affected
• Hard to distinguish from mutualism or parasitism

ex- shark and remora fish

What is protocooperation

both species are benefited, but not obligatory

ex- sea anemones and clownfish

How do hypotheses, theories, and laws differ?

Hypotheses are testable predictions

theories are well-supported explanations

laws are universally accepted principles.

When is it appropriate to use an experiment?

When you can control variables to test cause-effect relationships.

What are microcosms

self-contained experiments, with all or most conditions simplified and under control

What are mesocosms

larger experiments, natural components we can't control

What is a natural experiment

usually associated with a natural disaster, with a change that is outside the control of the investigator

What is an observational study

observes natural changes that are outside its control, which can establish a correlation

What are the three types of models used in ecology?

Conceptual and graphical (diagrams), mathematical (deterministic equations), and Statistical (probabilistic methods to find patterns).

What is Shelford's Law of Tolerance?

Species have an optimal range for environmental conditions, and survival is limited outside this range.

What is adaptation

change in behavior, physiology, morphology, or life history to become more suited for environment

Why is water important for life?

liquid at room temp

universal solvent

high specific heat

What is viscosity

thickness of a fluid

How do small aquatic organisms adapt to water viscosity?

Surface appendages (small) or streamlined bodies to reduce drag (large)

What adaptations help organisms survive deep water?

Bioluminescence, pressure tolerance, and low metabolism.

Major nutrients needed for algae and plants ?

nitrogen

phosphorus

potassium

How do organisms adapt to solute concentrations?

Osmoregulation through active transport and salt glands.

How can invertebrates use excess nutrients?

they can make shells

How do saltwater fish retain water?

constantly drinking water and osmosis pulling the water out through gills

How do freshwater fish retain solutes?

through urinating excess water, so the kidneys retain most solutes

How do aquatic animals cope with low oxygen?

Gills, increased surface area, and countercurrent exchange.

What is Countercurrent circulation

an adaptation where blood and water flow in opposite directions so that the concentration of O2 in water is always greater than the concentration in blood

How do organisms deal with low pH in water?

Use of buffering agents and protective mucus.

What are adaptations to high temperatures in water?

Isozymes and examples like thermophilic bacteria

What are isozymes

different molecular forms of the same enzyme that catalyze the same biochemical reaction

What helps organisms survive cold temperatures in water?

Antifreeze proteins, insulation, and high metabolism.

How does temperature tolerance affect species distribution?

Species can only thrive in environments within their thermal range.

How do plants move water from soil to leaves?

Root uptake → xylem transport via cohesion and tension.

How does soil salinization affect plants?

Reduces water uptake and causes stress or death.

What are the three types of photosynthesis?

C3, C4, and CAM

What is C3 photosynthesis

the most common pathway of carbon fixation in plants, where carbon dioxide (CO₂) is converted into a three-carbon compound called 3-phosphoglycerate (PGA) using the enzyme RuBisCO in the Calvin cycle

Advantages and disadvantages of C3 photosynthesis?

A: simplicity and efficiency in cool, moist, and high-CO₂ environments

D: struggles in heat

What is C4 photosynthesis

a specialized process where plants first fix carbon dioxide into a four-carbon organic acid in their mesophyll cells, and then transport this acid to bundle sheath cells. There, the CO2 is released and concentrated to drive the Calvin cycle with the enzyme Rubisco, significantly reducing energy-wasting photorespiration.

Advantages and disadvantages of C4 photosynthesis?

A: increased water and nitrogen use efficiency

D: higher ATP cost

What is CAM photosynthesis

a specialized biochemical pathway found in some plants, particularly those in dry environments, that allows them to open their stomata at night to collect carbon dioxide (CO₂) and store it as a malic acid in their vacuoles

advantages and disadvantages of cam photosynthesis

high water-use efficiency

lower photosynthetic capacity, slower growth rates

What are plant adaptations to prevent water loss?

Thick cuticles, reduced leaf area, sunken stomata.

Increased leaf edges dissipates heat how

by disrupting the boundary layer of still air around the leaf surface

a thinner boundary layer facilitates more efficient convective cooling and evaporative cooling

How do animals prevent water loss?

Concentrated urine, dry feces, nocturnal behavior.

how is internal gas exchange an advantage

keeps the lungs moist

How do animals regulate body temperature?

Behavioral changes and physiological mechanisms like sweating.

how do animals in salty environments remove salt

excreting it through specialized salt glands, located near the eyes, nose, or mouth

What is an endotherm and ectotherm

endotherm generates its own internal heat to maintain a stable body temperature, like birds and mammals

ectotherm relies on external heat sources, such as the sun

What is an Homeotherms and Poikilotherms

Homeotherms, or "warm-blooded" animals, maintain a stable internal body temperature through metabolic processes,

poikilotherms, or "cold-blooded" animals, have body temperatures that fluctuate with their environment

What is Allen's Rule?

Animals in cold climates have shorter extremities to reduce heat loss.

What is Bergmann's Rule?

Larger body sizes are found in colder climates, while smaller in hot climates

What is thermal inertia?

the resistance to a change in temperature due to a large body volume

What is phenotypic plasticity?

The ability of one genotype to produce different phenotypes in different environments.

What is Phenotypic trade-off

when a biological entity, such as a cell or organism, cannot simultaneously optimize multiple traits because an increase in one trait necessitates a decrease in another

What are behavioral adaptations to environmental change?

actions or habits that an organism does to survive and reproduce when its surroundings change

What is Microhabitat Selection

Temporary selection of the small-scale habitats due to changes in environmental conditions

What is an optimal foraging rate

Tradeoff between costs and benefits (efficiency)

What is optimal foraging theory?

Maximizing energy gained per energy spent.

What is diet mixing in foraging?

Eating multiple food types to balance nutrients.

What is central place foraging

Travel from home base to forage

What is acclimation?

Reversible physiological change due to environment.

What is a developmental response?

A permanent change during growth based on the environment.

What is dormancy and what are the 3 types?

Temporary halt in activity to survive harsh conditions.

torper

diapause

cryptobiosis

What is torpor?

Short-term reduced metabolic rate (e.g., hummingbirds at night).

What is diapause?

a state of suspended development and suppressed metabolism in animals, particularly insects, to survive unfavorable environmental conditions

What is cryptobiosis?

Metabolic near-death state in organisms like tardigrades.

What is Photoperiod

Timing of seasonal activities according to day length

Ideal for seasonal changes

could cause reproduction or dormancy or flowering

What is life history?

The pattern of survival, reproduction, and growth over an organism's life.

What is fecundity

the biological ability or potential to produce offspring

What is parity

studies the number of times an organism reproduces during its lifetime,

What is parental investment

any expenditure of parental time, energy, or resources towards an offspring that increases its chances of survival and reproductive success, at a cost to the parent's ability to invest in other offspring or aspects of their own fitness

What is longevity

a life-history trait, meaning the length of an organism's lifespan, which is shaped by natural selection and influenced by various ecological factors