IB Biology - Topic C

What are causes and consequences of biomagnification?

*Causes*: eating contaminated fish and shellfish, eating imported food exposed to DDT, eating crops grown in contaminated soil, infants through breast milk *Consequences*: damages liver [cancer], damages nervous system through developing brains, reduces reproductive success

How can one distinguish between a fundamental niche or a realized niche on a graph?

*Fundamental*: isolated species in "separately" line *Realized*: interacting populations in "mixed population" line

Compare macroplastic and microplastic.

*Macroplastic*: large, usually visible pieces of plastic, >1mm across *Microplastic*: macroplastic pieces, <1mm across, debris accumulates in areas called gyres (Atlantic, Pacific, Indian)

What affects the distribution of plants? What affects the distribution of animals?

*Plants*: temperature, water, soil pH, light, salinity, mineral nutrients *Animals*: water, breeding sites, food supply, temperature, territory

Compare primary and secondary succession.

*Primary*: begins with no life, no soil, new area (volcanic island), lichens and mosses, low biomass, low production *Secondary*: follows a disturbance of the primary succession, soil present, old area (following a forest fire), seeds and roots, higher biomass, higher production

What are pros and cons of DDT?

*Pro*: affordable and effective at killing mosquitoes carrying malaria, health costs reduced to treat malaria, used as insecticide in houses instead of crops *Con*: kills other insects, stays in environment for a long time and gets biomagnification in food chains, thinner egg shells in birds of prey, people exposed suffer other health risks (liver, neurological, reproduction)

1) What is the biotic index equation? 2) What does a higher score indicate?

1) *Relative number of indicator species in a habitat x pollution tolerance rating = biotic index* 2) Higher water quality

1) Define ecological succession. 2) An area with no vegetation colonized by a variety of species that gradually replace each other causes (this). 3) Interaction between living organisms and abiotic environment increases what? Decrease in what? 4) What will develop from this?

1) A transition in the species number or composition in a community over time 2) Gross production 3) Increase in amount of soil (mineral content) and organic matter; decrease soil erosion 4) A stable "climax" community

1) What is exchanged in an open ecosystem? How many systems are open? Example? 2) What is exchanged in a closed ecosystem? How many systems are closed? Example?

1) Both matter and energy. Most are open. Example: light and carbon dioxide are taken in while heat and oxygen are given off. 2) Energy but not matter. Not common, usually for experiments. Example: in bottle gardens, light passes into bottle and heat exits but nutrients are contained within.

1) Define ex-situ conservation. 2) Give some examples.

1) Conservation of species by removing them from their habitat 2) Zoos (captive breeding programs such as for pandas), botanical gardens (cultivation of plants that risk extinction), seed banks, storage of sperm and ova

1) Define in-situ conservation. 2) Give an example. 3) What are advantages?

1) Conservation of species within their own habitat 2) Florida Panther 3) Carried out in nature reserves so allows species to live in environment for which adapted; reduces possibility that habitat disappears and whole community is lost; threatened species in a reserve can be monitored; organisms continue to evolve

1) Define fundamental niche. 2) Define realized niche. 3) What happens when multiple species have the same fundamental niche?

1) Entire possible niche that a species may occupy (tree) 2) Actual niche within fundamental niche that a species occupies (specific area on the tree) 3) Adaptations and competition occurs; each species finds its own realized niche (many bird species in a tree but each in own niche)

Outline how transection works.

1) Establish a line to follow (outer edge to center area) 2) Mark a quadrant every 10-20m 3) Count plant or animal species being studied 4) Measure abiotic factor chosen in each quadrat to determine its effect on distribution

1) What causes disturbances in the ecosystem? 2) What are possible effects?

1) Natural and human events that disrupt the structure and rate of change in an ecosystem 2) Extreme climate can destroy a food web. Human population can encroach into territories of animals. Nutrient cycles can be disrupted by harvesting crops and removing nutrients. Pesticides remove selected and non-selected organisms from food chains.

1) Define richness. 2) Define evenness. 3) Which is less diverse: a large population dominated by one species or a moderate population with similar amounts of several species?

1) Number of different species present 2) How close in numbers the different species are 3) A large population dominated by one species

1) What is the equation for the Simpson Diversity Index? 2) What does a large or low value indicate?

1) See image. 2) High D indicates stability and diversity (a healthy ecosystem); low D value indicates new / less diverse (lowest score is one)

1) Define indicator species. 2) Indicator species need a particular environment to survive. A lack of a particular species indicates (this). 3) What does an indicator species provide information about? 4) What are two examples?

1) Species of varying degrees of tolerance used to measure abiotic factors and reveal the long-term effects of environmental stress 2) A change in the quality of the ecosystem 3) The health of an ecosystem which may lead to action to avoid extinction of threatened species 4) Stonefly larvae require unpolluted, well-oxygenated water. Rat-tailed maggots indicate high level of water pollution and low oxygen levels

1) What is the purpose of the Food Conversion Ratio (FCR)? 2) Lower ratio means (?). 3) What is the equation?

1) To measure an animal's efficiency at converting what it eats into increased mass 2) More efficiency 3) *Mass of food eaten ÷ gain in body mass over time = FCR*

Describe and give an example for the impact of alien species: 1) Interspecific competition 2) Species extinction 3) Predation 4) Biological control

1) Without a predator, invasive species can reproduce (US grey squirrel displaces UK red squirrel) 2) Outcompeting to the point of extinction of the native species (Nile Perch introduced in Africa, cichlid fish are becoming extinct) 3) Invasive species feeds on native species (Sea Lamprey introduced in the Great Lakes feed on trout) 4) Controlling nature (moth that feeds on prickly pear cactus was introduced in Australia to balance)

Predation

A consumer feeding on another consumer. Ex: bay-breasted warbler feeds on insects including dragonflies.

Gersmehl nutrient cycle

A diagram showing the inter-relationships between nutrient stores and flows between taiga, desert and tropical rainforest.

Whittaker climograph

A graph showing the relationship between temperature, rainfall and ecosystem type

Transect

A method used to ensure that there is not bias in a student's selection of a sample and it can be used to correlate the distribution of plant or animal species with an abiotic variable.

Pyramid of energy

A model of the energy flow through ecosystems.

Climate

A property that emerges from the interaction of a number of variables including temperature and precipitation.

Define keystone species.

A species that has a disproportionate effect on the structure of a community

Endemic species

A species that is native to an area

Alien species

A species that is not native to an area but is introduced my humans

Keystone species

A species which has a disproportionate effect on the structure of an ecological community.

Invasive species

Alien species that have significant changes on the new ecosystem

Food web

All of the possible food chains in a community

Trophies level

An organisms feeding position in a food chain.

What is bottom-up and top-down?

Bottom-up is availability of resources. Top-down is referring to predation.

Open ecosystems

Ecosystems that exchange both matter and energy the the surroundings

Closed ecosystems

Ecosystems that exchange energy but not matter with the surroundings

Isolated ecosystems

Ecosystems that exchange neither matter or energy with the surroundings

What decreases the size of the population?

Emigration

The three phases in a Sigmoid population growth curve

Exponential, transitional, and plateau

What increases the size of the population?

Immigration

Production of nitrogen

Lighting and the Haber result in the production of ammonia from nitrogen gas in the atmosphere

Food conversion ratio

Mass of food eaten/ desired output

Formula to calculate gross and net production values

Net production = gross production - respiration

Why is nitrogen needed?

Nitrogen is vital for the production of building and production of amino acids and proteins

Commensalism

One organism benefits and the other is neither harmed or helped

Parasitism

One organism feeds off another but does not normally kill it.

Denitrification

Oxygen is in short supply in waterlogged soils,, decreasing aeration, which leads to the loss of bio-available nitrogen.

Why is phosphorus needed?

Phosphates are components of ATP, cell membranes, and skeletons

Phosphorus cycle inorganically

Phosphoric rocks weather and erode

Phosphorus cycle organically

Plants and animals wastes

Consequences of marine plastic pollution

Plastics absorb other persistent organic chemicals and this create toxins Animals eat or become tangled in plastic pollution

Herbivory

Primary consumers feeding on producers. Ex: bison feed on grasses and limpets feed on algae growing on rocks.

Primary succession

Rock surface, then soil starts to develop, then larger plants start to colonize, and finally trees

Recognize parts of a tolerance graph.

See image.

Understand Gersmehl's nutrient diagrams.

See image. Size of circle represents the amount of store available. Arrows represent the flow of energy and nutrients. All three of his diagrams are examples of open ecosystems. Tagia (temperate): bigger Litter Desert: bigger Soil Tropical rainforest: bigger Biomass

Production of nitrogen inorganically

Some bacteria convert it into ammonia (NH3), which can be absorbed by plants

Define the following types of symbiotic relationships and give examples: 1) Mutualism 2) Parasitism 3) Predation 4) Herbivory 5) Competition 6) Give an example of a symbiotic relationship.

Symbiosis is the interaction between living things: 1) Help each other, neither harmed (clownfish and sea anemone, lichens - algae and fungi) 2) Parasite benefits and the host is harmed (tapeworm and human, tick and deer) 3) Predator benefits with food and the prey harmed by being violently killed and eaten (lion and antelope, snake and rat) 4) Eating of vegetation, predation of plants (giraffes and leaves; koala and eucalyptus) 5) One gets food and the other is harmed by not getting food; Intraspecific = same species (lions and cheetah), Interspecific: different species (nurse shark and octopus) 6) Coral lives in nutrient-poor water and has a mutualistic relationship with algae zooxanthellae's ability to photosynthesize. Coral uses the glucose, amino acids, and oxygen from the algae. And the algae uses the coral for carbon dioxide, ammonia, and phosphates.

Secondary succession

Takes place in areas where there is already, or recently has been, an ecosystem. It occurs when man made structures are abandoned.

Realized niche

The actual mode of existence of a species, which results from the combination of its adaptations and competition with other species.

Net production

The amount of gross production remaining after subtraction of the amount used for respiration by the trophies level.

Eutrophication

The nutrient enrichment of water as a result of runoffs, which leads to algal blooms, which block light from other plants.

Niche

The organism's role in the ecosystem, habitat, nutrition (feeding habits), interactions with other organisms (predator / prey)

Fundamental niche

The potential mode of existences of the species, given the adaptations.

Biomagnification

The process by which chemical substances become more concentrated at each trophies level.

Gross production

The total amount of organic matter produced per unit area per unit time by a trophies level in an ecosystem

Biomass

The total dry mass of organic matter in organisms or ecosystems

Bioaccumulation

Toxins concentration increases in an individual.

Competitive exclusion principle

Two species cannot coexist in the same habitat if their niches completely overlap.

How does competitive exclusion occur?

Two species in an ecosystem cannot occupy the same niche. If another species tries to do so, there will be competition for resources. One will be better suited for the niche and the other will die or compete for a niche elsewhere (displaced).

Mutualism

Two species live in a close association where both organisms benefit from the association

When does the growth curve plateau?

When birth rate and death rate are equal

When do alien species become invasive?

When they: have no predators, have no local competition, rapidly reproduce, outcompete endemic species (competitive exclusion)

Limiting Factors

a factor that is the most scarce in relation to an organisms needs Ex: temperature, water, breeding sites,light intensity, soil pH, soil salinity, and mineral nutrients