BIO1108 FINAL

Innate immunity

Innate immunity

present BEFORE any exposure to pathogens, nonspecific

What are the barrier defenses of innate immunity

Mucus skin (acidic), exoskeletons in incests

What are the internal defenses of innate immunity

Macrophages (white blood cells that eat foreign organisms in response to histamine), Natural Killer Cells or NK (kills abnormal cells) Antimicrobial peptides (produced by incests)

Acquired immunity

A specific response to pathogens, unique to vertebrates

What are the defenses of acquired immunity

1. B-cell lymphocytes (white blood cells made in bones that can produce antibodies)

2. T-cell lymphocytes (mature in thymus gland and works with MHC proteins)

3. MHC proteins (highly variable and bind to antigens inside the cell)

Fission/budding

type of asexual reproduction, animal splits into two new ones or new individuals grow out of parents body

Fragmentation

type of asexual reproduction, broken off pieces can grow into new organisms examples: starfish, sponges, cnidarians, some segmented worms, sea squirts

Parthenogenesis

type of asexual reproduction, egg develops without being fertilized. can be haploid or diploid examples: many fews, aphids, a few fish, frogs, lizards (Komodo dragons and hammerhead sharks)

Where does fertilization occur

In the oviduct (fallopian tubes)

What stage of development does the embyro implant into the uterine lining

At the blastocyst (lopsided blastula=hollow ball of cells) stage (???????)

What major organ or system does the ectoderm form?

Nerves and external tissue, in chordates a neural fold forms in the dorsal ectoderm of the embryo

What major organ or system does the endoderm form

interior lining of gut and respiratory system + organs that directly pour into gut but don’t have muscle-e.g.g. pancreas, liver, etc

What major organ or system does the mesoderm form

middle tissues like blood, muscle, cartilage, bone, and organs with those tissue

How is the neural fold formed in the embryo?

As the grove deepens, the ectoderm pinches together above, forming the neural tube

What genes are involved in patterning during embryonic development?

Hox/homeobox genes program complex patterning and segmentation (head, body, tail, limbs, etc)

What is the difference in the complexity of hox genes when comparing chordates and vertebrates?

Chordates have few hex copies Vertebrates/humans (also chordata) have more copies differentially expressed in different tissues during development. - vertebrates go through multiple whole genome duplications-polyploidy events that give us 4 times the number of hox genes

Know how nerve cells propagate a signal and how a signal is transmitted from one nerve cell to the next

??????

Organismal Ecology

subfield of ecology, studies how an organism's structure, physiology, and behavior meet the challenges posed by the environment

Population ecology

subfield of ecology, focuses n the factors that affect how many individuals of a particular species live in an area and distribution of alleles in those populations

Community ecology

subfield of ecology, deals with interations between species in a community

Ecosystem ecology

subfield of ecology, emphasizes energy flow and chemical cycling among the various biotic and abiotic components

landscape ecology

subfield of ecology, deals with arrays of ecosystems, how they are arranged in geographic regions, and how they exchange energy, organisms, etc.

Global ecology

subfield of ecology, studies the functioning and distribution of organisms across the biosphere (the sum of all the planet's ecosystems)

What are the major causes of the variation in temperature, wind, and precipitation across the planet?

1. Angle of sunlight: affected by latitude, seasons, and local topography. Sunlight has to pass through more atmosphere near the poles, fewer photons per land area.

2. Global wind patterns: rooted in points at the equator moving much faster than points near the poles during the earth's revolution

   • a residual effect of displaced air is wind, can be strong at the poles and the equator

   • ascending moist air causes lots of rainfall near equator

   • descending dry air at 30 degrees latitude leads to deserts

3. Mountains: has significant effect on the amount of sunlight that reaches an area, local temperature and rainfall patterns

   • uplifted air cooling and dropping all moisture on the windward side of mountains. This leaves only dry air once it descends on the leeward side of the mountain range, which LEADS TO RAIN SHADOW

Climate

determines the distribution and structure of terrestrial biomes and has a great impact on the distribution of organisms. - sometimes processes such as grazing or fire frequency help differentiate biomes

Tropical forest

-Areas of relatively constant temperature and usually lots of rain

-Highest species diversity of any biome, especially with elevational gradients

Desert

-low precipitation prevents the growth of trees, usually lots of open space between plants

-Cacti are only in North and South America, but cactus-like plants exist in the deserts of Africa, Australia, & Asia due to similar selective pressures.

Savanna

• grass-dominated ground habitat with evenly spaced, scattered trees

-Africa: lots of vegetation of grazing animals

-Southeastern US (including most of Southern GA): was formerly highly flammable Longleaf Pine/Wiregrass savanna *Now only a few fragments in the area burn frequently such as military bombing ranges (Ft. Benning and Stewart)

Chaparral

-shrubland prone to frequent fire in "Mediterranean" climates with very seasonal rainfall (usually cool)

-this is followed by periods of warm drought; fog from ocean assists in the survival of shrubs

-includes: Coastal California, South Africa, etc.

Temperate Grassland

-frequent burns or grazing usually prevents tree establishment

-grass gets taller as rain increases

-Underlying rich soil makes it ideal to grow vast areas of grass crops (corn, wheat, barley, rye, etc.) *This makes it one of the most degraded biomes

-Includes: US prairies, further west of Rocky Mt. rain shadow

Temperate Broadleaf Forest

-More widley distributed in Northern Hemisphere than Southern Hemisphere

-Many plant genera only found in China and East US *Others found only in East US, Europe, and China

Northern Coniferous Forest

-Only in Northern Hemisphere -Conifer leaves (needles) don't dry out in cold, dry air -Extends southward at higher elevations in the mountains of West North America *Occurs at a few spots as far south as North Carolina in the east

Tundra

-Permafrost

-Layer of soil a few inches down that remains frozen all year *Prevents the establishment of trees

-Cold, high winds

-short growing season limits plant height

-No land in southern hemisphere at proper latitude for Tundra

High mountains

-habitats similar to tundra above the treeline -Alpine Tundra

Photic zone

type of aquatic biome zonation, sufficient light for photosynthesis

Aphotic zone

type of aquatic biome zonation, little light penetrates

Benthic zone

type of aquatic biome zonation, the body of any body of water on the substrate

Pelagic zone

type of aquatic biome zonation, open water

Abyssal zone

type of aquatic biome zonation, oceanic benthic zone below 2000m

Oligotrophic lakes

-low nutrient levels -low vegetation -high oxygen -clear water

Eutrophic lakes

-high nutrient levels -lots of vegetation -high levels of decaying organic matter because of depleted oxygen, murky water

What are the types of aquatic biomes?

1. Wetlands

2. Streams and Rivers

3. Estuaries

4. Intertidal Zones

5. Oceanic Pelagic Zone

Lakes

permanent bodies of standing water

Wetlands

-areas with saturated soil for significant portions of the year *many also dry out for extended periods -frequent on margins of lakes and ponds may be tree, shrub, or herbaceous plant dominated

Streams and Rivers

-flowing water, oxygen level depends on turbidity (mixing with air) caused by flow rate -temperature and light are highly variable -Move nutrients and aquatic organisms from biome to biome

Estuaries

-where rivers meet larger bodies of water with significantly different chemistry and organisms -usually refers to freshwater rivers meeting saltwater sea/oceans *can also occur where rivers flow into large lakes with unique chemistry

Intertidal Zones

-places where tidal action creates unique ecosystems with organisms that can deal with inundation and desiccation twice daily for many areas *further from the shoreline inundation many occur only during extreme tide events

-can be rocky or sandy and extent of intertidal zones varies widely throughout the year *biggest difference between high and low tide is usually during the full moon

-Tidal action also travels very far upstream in larger rivers

Oceanic Pelagic Zone

-open ocean -typically low nutrient levels and low density of organisms *except in areas of nutrient upwelling -sometimes organisms concentrate around areas of food, but mostly widely spaced

-Despite low average density of organisms, vast area (70% of earth) means THIS BIOME CONTAINS A LARGE PORTION OF THE EARTH'S BIOMASS

population

a group of individuals of a single species living in the same general area- highly variable in definition depending on the study

density

-the number of individuals per unit area or volume; -the result of the interplay between processes that add individuals to a population and those that remove individuals from it: Birth, Death, Immigration, Emigration

dispersion

the pattern of spacing among individuals within the boundaries of the population

Clumped dispersion

individuals aggregate in patches - may be influenced by resource availability and behavior (social organisms)

uniform dispersion

individuals are evenly distributed; very rare, but influenced by social interactions such as territoriality (e.g. nesting penguins)

random dispersion

the position of each individual is independent of other individuals

exponential population growth

population increase under idealized conditions

• cannot be sustained for long in most populations

-under these conditions, the rate of reproduction is at its maximum *called the intrinsic rate of increase (r-max)

-this graph is usually a j-shaped curve

• the equation is dN/dt=r-maxN *N=population size * the result is the change in population over time

Logistic Population Growth

A more realistic population model limits growth by incorporating a carrying capacity

• carrying capacity (K) is the maximum population size the environment can support

-the equation is dN/dt=r-maxN (K-N)/K * (=exponential growth x % of carrying capacity remaining)

The human population

• increased slowly until 1650, then became exponential due to technological advancements

-the population grows by 1.5 million every week

• an equivalent of the US population is added every 4 years

biological community

assemblage of populations of various species living close enough for potential interaction

interspecific interations

-what populations are linked to

• affects survival and reproduction (biological fitness) of species engaged in the interaction

Competition (-/-)

• • increases survival and reproduction, - decreases survival and reproduction

Predation = +/- (being eaten is bad for survival and reproduction!)

Herbivory = +/- (basically predation on something photosynthetic)

Parasitism = +/- (being slowly eaten by small, multicellular organisms)

Disease = +/- (being slowly eaten by small, unicellular organisms)

Mutualism = +/+ (benefits both; corals, lichens, mycorrhizal interactions, etc.)

Commensalism = +/0 (rare for an interaction to have absolutely no effect)

Interspecific competition

when species compete for a particular resource that is in short supply

Competitive exclusion

• what strong competition leads to

• the local elimination of one of the two competing species

Ecological niche

the total of an organism’s use of the biotic and abiotic resources in its environment

niches

Ecologically similar species can coexist in a community if there are one or more significant difference in these

Cryptic coloration

camouflage, makes predators or prey difficult to see

Aposematic coloration

warning coloration for predators to stay away

Mimicry

one prey species may gain significant protection by mimicking the appearance of another

Batesian mimicry

a palatable or harmless species mimics an unpalatable or harmful model

Müllerian mimicry

two or more unpalatable species resemble each other, giving added protection to both

Three levels of biodiversity

-Genetic diversity

–Species diversity

–Ecosystem diversity (think of driving across Iowa vs. driving across California)

Extinction vortex

-occurs in a small population that is prone to positive feedback loops

KEY FACTORS DRIVING THE VORTEX:

1. loss of genetic variation necessary to enable evolutionary responses to environmental changes 2.excessive homozygosity of deleterious mutations -(inbreeding depression)

Dominant species

most abundant or most biomass

invasive species

not naturally occurring, alters the species diversity of a community

Keystone species

not numerically dominant, but greatly affects the rest of the community

foundation species

change habitat and allow for a new community to develop

Invasive species

• a threat to biodiversity

-humans have moved species to new geographic regions

-introduced species that usually disrupt their new habitat/community

-islands are often vulnerable to the introduction of predators

Overexploitation

-a threat to biodiversity

-human harvesting of wild organisms at rates exceeding the populations' ability to rebound

-example: passenger piegon

Habitat loss and Fragmentation

-a threat to biodiversity

-human alteration of habitat is the single greatest threat to biodiversity

-Habitat destruction has brought about commercial, agricultural, recreational, and climate change

-natural landscapes are broken up, fragmenting habitat into small patches

ecosystem

all organisms living in a biological community plus all the abiotic factors with which they interact

• involves two processes energy flow and chemical cycling

Energy flow

-Energy flows THROUGH ecosystem entering as light and exiting as heat,

-while matter cycles within them

Trophic efficiency

• percentage of production transferred from one trophic level to the next

• about 90% of energy is lost with each transfer in a food chain

-as a result, there is a sharp DECREASE in biomass at successively higher trophic levels *it takes almost 10x as much land to generate enough primary production to sustain a CARNIVORE than it does to sustain a HERBIVORE

Nutrient cycling

nutrient cycles that move matter through an ecosystem involve both biotic and abiotic components and are often called BIOGEOCHEMICAL CYCLES

Global cycling nutrients

carbon, oxygen, sulfur, and nitrogen

Local cycling nutrients

phosphorous, potassium, and calcium

A grouping of species A, B, D, and E based on a trait that was present in the ancestor at node 2 would be considered:

Paraphyletic

If a locus in the genome has two alleles, and the frequency of one allele is 0.4 (40%), what is the frequency of heterozygotes in the population if the locus is in Hardy-Weinberg Equilibrium?

48

Which nutritional modes are found in eukaryotes? (circle all that apply)

Photoautotroph and Chemoheterotroph

Which of the following supergroups contains multicellular organisms?

SAR Clade

Archaeplastida

Unikonta

Only Archaeplastida and Unikonta

Which of the following is NOT an example or component of innate immunity?

MHC protiens

Nerves cannot partially fire.

true

What is the closest-related animal to us that is capable of reproduction through fragmentation?

Sea Squirt

Two flowers live in the same forest but bloom at different times of day. Their reproductive barrier is:

Temporal Isolation

Coal primarily comes from members of which modern plant lineage?

Gymnosperms

Which of these characteristics evolved at node E?

Skull

What ion rushes into the axon during an action potential ?

Chlorine

At what embryonic stage does implantation occur in placental mammals?

Blastula

The brain forms from what embryonic tissue layer?

Ectoderm

Ancient duplications in Hox genes directly lead to the increase in complexity seen in vertebrates relative to lancelets.

true

Match the following characteristics to the supergroup that best matches:

Contains humans - Unikonta Contains plants - Archaeplastida Contains Euglena - Excavata Contains Malaria - SAR Clade

Match the letters to the organism that belongs in that place on the phylogenetic tree

A - Turtle B - Frog C - Shark D - Earthworm E - Coral