ESS Short Test

Individual

One Living Organism

Species

A group of organisms that share common characteristics and that interbreed to produce fertile offspring.

Fertile

Able to produce offspring

Genetic Diversity

Range of genetic material present in a population of a species

Habitat

The environment in which a species normally lives

Habitat Diversity

Range of different habitats in ecosystem or biome

Niche

Particular set of abiotic and biotic conditions and resources to which an organism or population responds.

Population

A group of organisms of the same species living in the same area at the same time, and which are capable of interbreeding.

Importance of understanding population

• Reveals population trends and underlying threats, enabling early identification of species decline and causes of pressure. 

• Informs targeted, evidence-based conservation actions and efficient allocation of limited resources. 

• Supports long-term monitoring, adaptive management, and stronger policy decisions through reliable population data.

Population Regulation

Check the growht of population

Limiting factors

factors that will limit a population’s growth

• Plants - nutrients, water, light, more.

• Animals - space, food, mate, shelter, water, more.

Density depedent Factors

More influential as population density increases, acting like a self-adjusting break on population growth

Density-Indepdent Factors

Happen regardless of population density

Feedback Loops

Nodes and Flows

• Positive Feedback = enhancement/amplification of an effect by the influence. 

• Negative Feedback = mechanisms help to maintain stability.

Carrying Capacity

• the maximum number, density, or biomass of a species that a specific area can support sustainably.

  • Not a fixed number

  • Influenced by limiting factors

S Shaped

initial rapid growth (exponential growth) - then slows down as carrying capacity (K) is reached.

J Shaped

J shaped - initial slow growth - increasingly rapid - not slowing down as population increases.

Organisms having J curve growth = tend to produce many offspring rapidly and have little parental care (e.g. insects)

Sudden decrease due to limiting factors → called population crash (mostly caused by abiotic factors)

Population Dynamics

How a population changes over time , including how fast it gains or loses indivudals

Binomial Nomenclature Rules

• First name = Genus

• second name = species 

• Organisms in the same genus share similar traits 

• Genus: capital letter 

• species: lowercase 

• Write both in italics (or underline when handwritten)

dichotomous keys

allows for efficient identification and prediction of characteristics

composed of a series of questions or statements based on the physical characteristics of the organisms concerned and operates as a kind of flow chart

deoxyribonucleic acid (DNA) surveys

method to identify and predict characteristcs of organisms

Keystone Species

Disproportionatly large effect on community structure

removal can trigger trophic cascades and potential ecosystem collapse

Niche

describes the particular set of abiotic and biotic conditions and resources upon which an organism or a population depends

Ecological Niche

role of a species in an ecosystem. The niche comprises all biotic and abiotic interactions that influence the growth, survival and reproduction of a population, including how food is obtained.

Sustainability

natural property of ecosystem

inputs are balanced by outputs in a steady-state ecosystem

evidence for some ecosystems persisting for millions of years, for example, tropical rainforests

tipping point

can be caused by human activitiy

collapse of original ecosystem and development of new equilbrium

Biosphere Integrity loss

Changes to this have passed crucial threshold. Disturbance of ecosystem due to human activity has led to loss of biosphere integrity

Extinction rates prove this evidence

This damage can be slowed down by the integriyt of the ecosystem

Order

individual → species → population → Community→ecosystem→Biome→biosphere

Fertile Offspring

the ability to produce children that have the ability to produce more children

biodiversity

Habitat diversity

Species Diversity

Genetic Diversity

Interlinked and play vital role in resilience

Ecosystem relies on all three factors to remain in dynamic equilibrium, be resilient

Habitat Diversity

Variety of different ecosystems or habitats within a specific area

Habitat

abiotic and biotic environment in which a speices usualy lives

Each supports a unqiue set of species adapted to its specific condidionts

Species diversity

The number of variety of species within a given habitat or ecosystem.

Considers both the richness and evennes of species.

Richness = number of distinct speicies present

Eveness = relative abundance of species

Genetic Diversity

Variety of genetic traits and characteristics within a population or pseicies.

Genetic diversity is most important because it allows speicies to adapt and evolve over time

diverse gentic pool = greater chance for species to survive environmental chagnes

Resilience

helps ecosystem avoid tipping points and maintain stability by recovering when desturbed

Methods to gather insight into regional biodiveristy

Collaborative apporach between

• citizen science

• Government funded agencies

• Organisations

• Indigenous Knowledge

• Parabiologist

Simpson’s reciprocal index

Tool used to quantitatively measure biodiveristy

Takes into account Richness and eveness

Simpson’s recirporcal index

D=N(N-1)/ sum of n(n-1)

Where:

D is the Simpson Diversity Index.

N is the total number of individuals across all species.

n is the number of individuals of a particular species.

sum of n(n-1) is the sum of the product of the number of individuals for each species and one less than the number of individuals (n) for that species.