General Biology 2 Exam 4

Types of prokaryotes

Bacteria and archaea

How prokaryotes differ from eukaryotes

Prokaryotes are single celled, they may stick together to form associations and biofilms, generally much smaller than eukaryotes, chromosome is single circular double stranded DNA, exchange genetic material extensively

Prokaryotes

The oldest, structurally simplest, and most abundant forms of life

Differences between bacteria and archaea

Different lipids in plasma membranes, different molecules for support in cell walls, archaea are more similar to eukaryotes in DNA replication and gene expression

Bacteria and archaea

Can be autotroph or heterotroph

Extremophiles

Organisms that can survive in extreme environments such as extreme temperature, pressure, and salinity

Biological importance of prokaryotes

Abundant, diverse habitats, base of some food webs

Examples of extreme environments

Morning glory pool (hot spring) and the Dead Sea (hypersaline)

Koch’s germ theory

The microorganism must be present in every case of the disease and absent from healthy individuals, the putative causative agent must be isolated and grown in pure culture, the same disease must result when the cultured microorganism is used to infect a healthy host, the same microorganism must be isolated again from the diseased host

Virulence

Ability to cause disease, heritable variable trait

Crowding and poor sanitation

What leads to an increase in virulence

E. Coli

Example of a species with both virulent and harmless strains of bacteria

Microbiome

Community of microbes that naturally inhabit body or parts of the body

Bioremediation

Living organisms (ex. bacteria) are used to decontaminate affected areas

Example of bioremediation

Some species of bacteria are able to solubilize and degrade oil from spills on beaches

Protists

Cannot be classified as plants, animals or fungi

Why protists are important primary producers

They provide food for a large proportion of aquatic species

Life cycles of protists

Most are free-living, some are parasitic, asexual reproduction is common, sexual reproduction may occur when conditions deteriorate

Ecological importance of protists

Produce oxygen, producers in freshwater and saltwater ecosystems, major component of plankton, many are symbionts

Examples of mutualism

Coral reefs and photosynthetic protists in tissues of corals (animals) or termites and parabasalids

Malaria

One of the world’s worst chronic infectious diseases caused by five species of parasitic protist

Fungi

Eukaryotes that grow as single-cell or large, branching networks of multicellular filaments, absorb nutrients from dead organisms, and are the world’s most important decomposers

Common ancestor

Fungi and animals share

Characteristics of fungi

Heterotrophic, cells release digestive enzymes and then absorb resultant nutrient molecules, most are saprobes, some are parasitic, several in mutualistic relationships with other organisms

Important economic and ecological impacts of fungi

Antibiotics were discovered, fungi live in close association with plant roots and provide nutrients for the plant, and the carbon cycle was accelerated

Saporophyte

Fungi that digest dead plant material, help cycle carbons through terrestrial systems

Carbon cycle components

Fixation on carbon by land plants, and release carbon dioxide from cellular respiration

Population

Consists of all individuals of the same species living within a specific area, can fluctuate based on changes in the environment, natural disasters, and competition between species

Distribution

A geographic range which has been influenced by biotic and abiotic factors

Uniform distribution

Individuals are equally spread apart

Example of uniform distribution

Territorial birds (penguins)

Random distribution

Individuals are spaced at unpredictable distances from each other

Example of random distribution

Plants with wind dispersed seeds (dandelions)

Clumped distribution

Occurs when individuals form social groups or resources are in small areas

Example of clumped distribution

Elephants traveling together

Sessile and mobile

Types of sampling methods

Examples of sessile sampling methods

Quadrants and line transects

Example of mobile sampling method

Mark and recapture

How mark and recapture works

percent marked is equal to average percent marked “recaptured”, individuals don’t move in or out of study area, individuals mix between captures, no capture bias, individuals do not learn to avoid capture, individuals do not change behavior because of being captured

Demography and life history

Depends on births, deaths, immigration, and emigration

Populations grow

Due to births and immigration

Populations decline

Due to deaths and emigration

Immigration

Occurs when individuals enter a population by moving from another population

Emigration

Occurs when individuals leave a population to join another population

Survivorship curves

Show the distribution of individuals in a population according to age

Fitness trade-offs

Every individual has a restricted amount of time and energy at its disposal, its resources are limited

High fecundity (r selected)

Tend to grow quickly, reach sexual maturity at a young age, and produce many small eggs or seeds

High survivorship (k selected)

Tend to grow slowly, invest their energy and time in traits that reduce damage from enemies, and increase their own ability to compete for resources

Exponential and logistical

Types of population growth

Exponential growth

Not dependent on population size (density independent) rare in real world, colonization of a new habitat, recovery after disaster

Logistical growth

Dependent on population size

Carrying capacity

The number of people or other living organisms that the environment can support with limited resources

Limiting factors

Density dependent and independent

Example of density independent factors

Limiting resources (food, space, etc)

Example of population crashes

reindeer population decreased due to over foraging of food supplies

Population cycle

Usually exhibits predator-prey dynamics and how they change over time

Metapopulations

Patches of habitat are linked by immigration/emigration sources and sinks, useful model for conservation biology

Behavior

Response to a stimulus

Foraging behavior

What, how and when to eat

Optimal foraging

Balancing of costs and benefits

Mating systems

Monogamy, polygamy, promiscuity

Monogamy

One female mates with one male, forming a pair bond (common in birds)

Polygamy

One male mates with two or more females, often occurs in situations where a male defends a territory of resources

Promiscuity

Males and females each have two or more sexual partners; some females choose multiple mates while others are coerced

How animals navigate

Piloting, compass orientation, and true navigation

Piloting

The use of familiar landmarks

Compass orientation

Movement oriented in a specific direction

True navigation

The ability to locate a specific place on Earth’s surface

Example of navigation

Sea turtles using magnetic map orientation

Migration

The long-distance movement of a population associated with a change in seasons

Communication

The type of signal used by an organism correlates with its habitat

Forms of communication

Singing, threatening gestures, language, bees’ waggle dance

Altruism

Behavior that has a fitness cost to the individual exhibiting it and a fitness benefit to the recipient

Hamilton’s rule

Altruistic behavior is most likely met when the fitness benefits of altruistic behavior are high for the recipient, the altruist and recipient are close relatives, and the fitness costs to the altruist are low

Coefficient of relatedness

The mean numbers of genes shared between two individuals

Direct fitness

Derived from an individuals own offspring

Indirect fitness

Derived from helping relatives produce more offspring than they could produce on their own

Ecology

The study of how organisms interact with each other and their environment

Levels of ecological study

Organismal, population, community, ecosystem, global

Conservation biology

The effort to study preserve and restore threatened populations, communities and ecosystems

Biotic factors

Living factors related to organisms that limits distribution

Abiotic factors

Non-living factors that that limit distribution

Niche models

Show the range of conditions tolerated by a species

Climate patterns

Climate is the long term weather conditions found in the area

Average temperature and precipitation

Influences amount of biomass generated

Aquatic biomes

Lakes, streams, rivers, ocean

Salinity

The proportion of solutes dissolved in water

Water depth and sunlight

The ocean is divided into different zones depending on

Types of nutrient availability

Coastal runoff, ocean upwelling, lake turnover

Commensalism

Association between organisms where one benefits and the other is not benefited or harmed

Interspecific competition

Members of different species use the same limiting resources

Intraspecific competition

Occurs between the same species

Competition

Lowers fitness of both individuals involved

Niche overlap

The degree to which species share the factors regulating population growth

Fundamental vs. realized niche

Theoretical range vs. proportion actually occupied

Consumption

An agent of natural selection

Evolutionary arms race

A repeating cycle of reciprocal adaptation

Inducible defenses

Defensive trait in response to the presence of a consumer

Mimicry

A harmless species mimics the coloration of a harmful species

Consecutive defenses

Camouflage, aposematic coloration