IB BIO YR 2 Unit 2

Habitat

natural home or environment of an animal plant or other organism

-provide the organism with all the resources it needs to survive and reproduce

-geographical location

-type of environment

-physical location

Organism

any individual living thing that can function on its own, such as a human, plant, animal, fungus, or bacterium

Species

group of organisms that can reproduce with each other to produce fertile offspring

Population

-1 species in 1 location at 1 time

work together to live and reproduce

Community

formed by populations of different species living and interacting with each other in a habitat

-predator vs prey

-herbivory

-competition for resources

-parasitism

-mutualism

Ecosystem

location where a community of organisms interact with each other and the abiotic environment

Biotic

means relating to, produced by, or caused by living organisms

Abiotic

non living or relating to things in the environment that are not alive

Adaptions

any inheritable trait that makes an organism better able to survive and reproduce within it’s habitat

Shelford’s Law of Tolerance

organisms have optimal survival rates for abiotic factors

organism moves from areas with optimal conditions there is a decrease in survival rates

Optimum Range

the specific set of environmental conditions where an organism thrives, grows, and reproduces most successfully

Zone of Stress

the range of environmental conditions where an organism can survive, but experiences difficult conditions that lower its growth, health, and reproduction

Zone of intolerance

the outer range of an environmental factor where conditions are too extreme for an organism to survive

Seminatural habitat

an environment that has been significantly modified, shaped, or managed by human activity, but still retains a diverse community of native wild plant and animal species and largely intact ecological processes

Belt Transect

strip or belt across habitat

-uses quadrat

-abundance, frequency, density, % cover

-more detailed quantitative data

-takes longer

Conditions required for Coral reefs

• Water Clarity

-zooxanthellae requires light for photosynthesis

-coral requires clear water so the light can reach the zooxanthellae

• Water depth

-light is rapidly absorbed by seawater and doesn’t penetrate great depths

-coral grows best at depths of 50m

• Temperature

-16 celcius-34.5 celcius

-low temps kill the corals and high temps cause the zooxanthellae to expel from the coral making it bleached

• Salinity

-23-42 ppt is tolerable salinity range

• pH

-8.0-8.3 ocean acidification is a threat to coral reefs

Obligate Anaerobes

cannot survive with oxygen

-live in an oxygen free environment

-perform anaerobic respiration

Facultative Anaerobes

can live with oxygen or without oxygen

-anaerobic respiration without oxygen

-aerobic respiration with oxygen

Obligate Aerobes

cannot live without oxygen

-live in oxygen rich environments

-perform aerobic respiration

Prokaryote

a single-celled organism that lacks a membrane-bound nucleus and other internal membrane-bound organelles

Photosythesis

Autotrophic Nutrition

make their own food

Archea

are prokaryotes that are found in a wide variety of environments, and they are metabolically diverse

Phototrophs

use light to make ATP with no oxygen

Chemolithotrophs

oxidize inorganic compounds

the inorganic compund molecule (fuel) the archeon strips electrons from it (oxidation) the flow makes ATP

Organotrophs

use organic compounds to make ATP

Omnivore

eat plants and animals. have a mixture of sharp incisors for ripping through meat, and flat molars.

Herbivore

eat predominantly plants, have large flat teeth for grinding seeds, along with strong jaws.

Family Hominidae

Some members of the family Hominidae are herbivores and others are omnivores.

Predator

hunt and kill

Prey

avoid predators

Strangler Ephiphytes

germinate in the branches sending aerial roots down that strangle the tree preventing it from getting nutrient

Epiphytes

grows on canopy trees

-broad flat leaves maximize photosynthesis

-flexible growth

Shade Tolerant Plants

branching (more surface area=more photosynthesis)

broad leaves

high concentration of chlorophyll

Fundamental Niche

the niche an organism could potentially occupy in the absence of competition

adaptions to environmental zone of tolerance

Realized Niche

the niche that an organism actually does occupy due to competition

Competitive Exclusion

no two species can occupy the ecological niche

the better adapted species excludes the other forcing it to a smaller realized niche

Exclusion Venom

• produce venom in glands to kill prey.

• Venom is injected into the prey.

• Toxins in the venom immobilize or kill the prey.

• Examples include many snakes and insect predators like scorpions.

Mimicry

Prey: Resembling poisonous or unpalatable species to deter predators; examples: hoverflies mimic bees/wasps, leaf insects mimic leaves

Nocturnal

Being active at night or during the day to avoid predator activity.

Holozoic Nutrition

 is a form of heterotrophic nutrition where an organism ingests food

• Internally digests food

• Absorbs and assimilates the nutrients from digested food.

Heterotrophic Nutrition

cannot make their own food, and they must take their food from other organisms.

Mixotrophic Nutrition

can behave as an autotroph by carrying out photosynthesis, and act as heterotrophs by feeding on other organisms.

-Euglena are freshwater protists

Obligate Mixotroph

Require both autotrophic and heterotrophic nutrition to survive
Cannot meet nutritional needs using only one mode

Liana

climbing mechanisms (vines climb up the tree different species have evolved different)

flexible and thin

large broad leaves

Decompose

Camouflage

Helps predators blend into the environment to sneak up on or ambush prey

Facultative Mixotroph

Can switch between autotrophic and heterotrophic nutrition
Able to meet all nutritional needs using either mode depending on resources

Saprotrophic Nutrition

are heterotrophs that obtain nutrients by external digestion of food.

bacteria and fungi are referred to as decomposers.

Allelopathy

is the release of chemicals by one organism which influences the germination, growth, survival or reproduction of another organism.

Reproductive isolation

a collection of physiological, behavioral, and genetic barriers that prevent different species from interbreeding to produce viable, fertile offspring

Genome

is all of the DNA (genetic information) in a cell.

-size is measured in nitrogen base pairs (bp) which form the bonds between the two strands of DNA.

Usually sizes are measured in:

• Kilobases (1kb = 1000bp) 

• Megabases (1Mb = 1,000,000bp).

• Gigabases (1Gb = 1,000,000,000bp)

Genome Sequencing

determines the entire genetic makeup of an organism.

Improving technology is reducing the cost and time of sequencing genomes.

Plant Adaptions

physical structures: thorns, sting (trichomes), tough fibrous leaves

chemicals: chili plants (spice)

Animal Adaptions

flat molars, grow teeth whole life, mouthparts specialized, aphids have stylets (suck out phloem from plant)

Black Walnut

Example of Allelopathy:

they release allelopatheic chemical called juglone

-reduces competition by inhibiting the growth of plants

Barnicales

example of competitive exclusion

-C barnicles have a wider fundemental niche but are excluded from lower tidal zones by faster growing Balanus

-Balanus cannot survive higher up so C barnecles live there instead

Polymorphism

refers to the existence of multiple forms of particular traits of characteristic within a species results from substitution

Single-Nucleotide Polymorphisms

organisms in the same species share most of their genomes but variation exists in the form of this

Variation

the differences in traits within a population

-mutations

-meiosis

-sexual reproduction

Overproduction

produce more offspring than can survive in an ecosystem populations increase until they reach carrying capacity

Competition for limited resources

when the population is at carrying capacity the overproduction and competition leads to natural selection due to survival of the fittest

Survival of the Fittest

Organisms with phenotypes which make them better adapted to their environment are more likely to survive and reproduce.

Heritability of Traits

encoded in the nucleotide base sequence of genes in organisms are required for natural selection. Organisms with favourable genes which increase their chances of surviving to reproduce in an environment, are more likely to pass their genes to the next generation.

Natural Selection operates with

variation, overproduction, survival of the fittest, heritability of traits, competition for limited resources