Bio Exam 1

Extremophiles

Extremophiles

-Able to withstand extreme heat or cold

Hyperthermophilic bacteria remarkably can survive at 235°F (113.25 °C) in hot vents VS Antarctic food web

Organisms are classified according to similarities and differences. All life can be placed into one of three domains:

Eukarya, (Eu)bacteria, Archaebacteria

All organisms can be traced back to a common ancestor. Length of lines reflects ____

genetic distance

most of the diversity is found among the ___

microbes (the longest lines)

-includes all bacteria and protists

plants and animals have evolved relatively ____

recently (short lines)

fungi are fairly closely related to ___

animals (such as humans)

Eukarya

Can be unicellular (ex. Yeasts), most are multicellular (ex. Humans)

Eukaryotic (with a true nucleus)

Widespread (including some on and in us! Ex. fungi)

(Eu)bacteria

Unicellular, but can form multicellular biofilms

Prokaryotic (without a true nucleus)

Found almost everywhere \n (including on and in us!)

Eu= true, eubacteria are true bacteria

There are more non human (eubacteria) cells in our bodies than human cells

Archaebacteria

Unicellular

Prokaryotic (without a true nucleus)

Found primarily in extreme environments (extremeophiles)

Living things:

1 are organized

2 require materials and energy

3 reproduce and develop

4 respond to stimuli

5 are homeostatic

6 have the capability to adapt

Levels of organization for living things:

Cell→ tissue→ organ/organ system→organism→population and species→community→ ecosystem→ biosphere

Cell

Structural and functional unit of life. MANY organisms are single-celled. Smallest and least divisible unit

Organizations of atoms and molecules (union of atoms); bounded by cell membrane (and sometimes cell wall)

Tissue

group of similar cells that perform a function

Ex. Cardiac muscle tissue to pump blood

organ and organ system

several tissues create organs that act with others to perform a function

Ex. Heart and cardiovascular system

organism

an individual that is a collection of organ systems (e.g., 12 systems in humans)

Population

larger group of organisms in same area (population ex. VSB students) or across areas (ex. St joes students) that can interbreed

Species

Any populations that can interbreed

Community

Interacting populations + species in area

Ex. Vsb students and squirrels on campus (cross species)

ecosystem

community plus physical environment

biosphere

worldwide sum of all ecosystems

Autotrophs

-“primary producers” that use solar (photosynthesis) or chemical energy (chemosynthesis; e.g., in deep sea vents) to convert materials to chemical energy

-autotroph literally means self nourishing

Chloroplasts

Allows green plants to capture solar energy and convert it into a useable form (glucose)

All organisms rely on plants at the most basic level, animals eat plants, we eat animals

Energy flows through the ecosystem following the laws of ____

thermodynamics

-You cant create or destroy energy but it can change form, which is why some energy is “lost” as heat

-Chemicals are being cycled, we use and reuse them

-Once created, chemical energy transferred from one “trophic level” to another (consumers– “herbivores” and “carnivores – and decomposers), with some converted to heat

genes

the functional units of heredity that contain DNA and are passed to offspring \n during reproduction.

DNA

is present in (nearly) all organisms and directs cellular functions.

variation

arises when genes are recombined, expressed differently, or mutated.

Organisms respond to external stimuli through ___

Five Senses

(ex. Chemoreception (picking up chemicals) and Photoreception (picking up light) )

…can then move toward or away from stimuli to improve chances for survival

Homeostasis

(“staying the same”) refers to the requirement that organisms maintain a relatively constant internal environment…

For example, human body temperature is maintained at ~98.6°F (37°C) across a wide range of ambient temperatures. It costs us energy to do so.

TNZ (thermoneutral zone)

the range of temps where you don’t have to adjust your BMR (ex. 75 degree weather on a beach is comfortable bc no work is required to keep body temp within ideal range)

TLC is ___, TUC is _

temp where you start to feel cold, where you start to feel hot

Adaptations

are features that make individual organisms better suited to a particular environment. Variation among individuals (see above) allows some to be a better fit at the time

Natural selection

results from better reproductive success of individuals w/favorable adaptations, leading to changes in characteristics of population over time (e.g., antibiotic resistance).

Evolution

is the change in frequency of traits in populations and species as a result of natural selection.

When you lose too much heat to environment __

need to GENERATE heat \n through shivering (and some other pathways)

Humans can survive colder temperatures better than hotter ones

When you gain too much heat from environment ___

need to DISSIPATE heat

through panting and sweating

Misinformation

“false information that is spread, regardless of whether there is intent to mislead.”

Disinformation

a subset of misinformation that is “deliberately misleading or biased information; manipulated narrative or facts; propaganda.”

Pseudoscience

a subset of  disinformation and a more insidious one in some ways; it is passing off non-science (unsupported claims) as “science” and suggesting/claiming that the information is scientifically rigorous

Hypotheses

created through Inductive reasoning are a tentative explanation for the observation(s).

Falsifiable and testable.

Prediction

created through deductive reasoning – “if hypothesis is correct, then…” something specific is true

Iterative process

Collected data and analyses lead to refinement of  hypotheses and final conclusions.

Inductive reasoning

makes broad generalizations from specific observations; it is inherently uncertain and falsifiable.

Deductive reasoning

uses one or more premises to reach a logically certain conclusion.

Experimental (Independent) Variable

Factor in experiment being tested

Response (Dependent) Variable

Result or change that occurs due to the experimental variable

Variety of biomes is due to several global and regional factors like:

Temperature

Latitude and altitude

Distribution of solar radiation on both a daily and seasonal basis

Global wind circulation patterns, coupled with oceanic temperatures

Mountains and rain shadow effect

Coasts moderate extremes of daily temperature, affecting local air temperatures and precipitation \n Monsoon climate

Lake effect

Global wind circulation patterns

Flows of warm and cold air form three large VERTICAL circulation patterns in each hemisphere.

The direction in which the air rises and cools determines the direction of the wind and moisture

At poles- tends to be drier

Air also circulates HORIZONTALLY (at surface) = “prevailing winds”

At about 30 degrees north and south latitude

Now cooler air typically sinks toward surface and reheats. As the dry air descends, it creates high pressure areas with lower rainfall. The result is the great deserts of Africa, Australia, and the Americas

At the equator/tropics

More direct sun heats the air and water evaporates. \n As warm, moist air rises and cools, the moisture is lost as rain (equatorial regions tend to be wettest).

Rising air goes toward poles and cools more

At about 60 degrees north and south latitude

The now rewarmed air again rises, producing a low pressure area, and cools and loses moisture, both leading to a region of relatively higher rain again.

Between 30 and 60  degrees –

Westerlies (W- to E). West coasts of continents in this band wetter

Between 30 °- equator –

air tends to circulate E to W

East coasts of continents in this band are wetter

Mountain and rain shadow effect

Moist air coming off ocean, rises and cools and loses moisture as rain, snow on windward side

Now dry air descends off mountain on leeward side \n leading to dry conditions and “rain shadow”

Coasts moderate temperature

land changes temperature more

During the day, land warms more quickly than ocean, air rises, and cool sea breeze blows off ocean to replace air over land

At night, land cools faster and breeze blows from the land to the sea

Monsoon climate

(gigantic circulation of air due to differential heating of air)

Occurs in spring-summer over land near large bodies of water \n (e.g., India/Pakistan near Indian Ocean; American SW near Gulf of Mexico)

Creates heavy rainfall (= monsoon climate)

Can last about six months, with the pattern reversing by November.

Monsoon formation

1. air over land heats more rapidly than that over water …

2. as result it rises, cools and loses its moisture

3. moist air from over the ocean replaces it.

4. this moist air in turn heats up, rises and loses its moisture as it cools.

Lake effect

In winter, arctic winds blowing over the Great Lakes warm and become \n moisture-laden.

When this air rises, it cools and loses its moisture as snow.

Significant variation exists within biomes as well

•Species segregate spatially w/different habitats \n and “microhabitats” \n Slides of aquatic and marine ecosystems below are good examples

•and temporally into “lifestyles” [e.g., nocturnal or diurnal]

= “Niche segregation”

[“habitats are a species address; niches are their profession”]

significance of niche segregation

allows species to coexist

Niche segregation in freshwater/saltwater biomes

Littoral Zone \n (shallow edge

Limnetic Zone (open water lit by sunlight)

Benthic Zone (bottom)

Profundal Zone (deep dark water)

Estuaries

Have inputs of both freshwater and saltwater and are important habitat for many species.

and important spawning and nursery sites for a variety of species \n (incl. shrimp; clams; oysters)

Four primary zones of oceans

littoral (near shore), pelagic (open water), benthic (bottom), and abyssal (deep oceans)

Life exists at all levels

Species richness –

the number of species in community or ecosystem

Species evenness –

how evenly the species are distributed (relative abundances)

Species diversity –

is a combination of both species richness and evenness, \n considering not only how many species \n are present but also how evenly distributed the numbers of each species are.

tends to be highest in tropics and subtropics

Ecosystems are composed of abiotic and \n biotic components

•Abiotic components include nonliving aspects such as sunlight, inorganic nutrients, soil type, water, temperature, and wind.

•Biotic components are the living entities at all levels.

Producers (“autotrophs”)

use abiotic nutrients and external energy and convert to a form used by them and other living things [here plants use solar E to produce chemical energy (glucose)]

Decomposers

break-down plants and animals that die and recycle inorganic nutrients, which are then used (again) by the producers

Consumers

Chemical energy is then transferred through trophic levels with some E lost as heat at each level

Photosynthetic autotrophs

are essential in terrestrial and most water ecosystems because they convert solar energy to chemical energy, provide O2, and recycle nutrients.

EX. green plants

In photosynthesis,

solar energy is used to transfer electrons from water to energy-poor CO2 molecules, forming energy-rich carbohydrate (glucose) molecules and O2

photosynthesis takes place in

chloroplasts

Two primary processes of photosynthesis

“Light reactions” use solar E and water to create O2 and high energy ATP and NADPH intermediates

ATP and NADPH then used to convert CO2 to higher energy carbohydrates in Calvin Cycle/”Dark reactions”

pyramid of energy flow through trophic levels

All non-autotrophs (=“heterotrophs”) must eat plants or something that ate plants

Producers/autotrophs-→ herbivores (primary consumers)-→carnivores (secondary consumers)-→top carnivores (tertiary consumers)

“keystone species”

when removed from the ecosystem will have disproportionately negative impacts relative to their abundance

Trophic cascades

are when predators (Level 3 consumers) are keystone species and directly limit the density and/or behavior of their prey and consequently have powerful indirect and positive effects on the lower trophic level(s), enhancing their survival. Can also have effects on abiotic aspects of ecosystem as well.

Reservoir

nutrient is unavailable to organisms (incl. producers) \n (e.g., fossilized remains, rocks, deep sea sediments)

Exchange pool

the nutrient/water is accessible (e.g., atmosphere, soil, water), serving as a source or receptacle

Hydrological cycle

Several “exchange pools”, including the atmosphere, surface water (oceans, lakes), ice, belowground aquifers, soil and organisms

Water “moves” through cycle due to evaporation and precipitation, transport by wind, animals and plants, and through both run-off and percolation…

Phosphorous cycle

Several “exchange pools”, including surface water, soil, sediment, organisms. \n Reservoirs include “hidden” sediment, rocks.

Phosphorus/phosphate enters cycle through weathering and mining, with some going directly to water and sediment in oceans/lakes and some to biota both on land and in water.

Once in biotic components, “moves” through typical trophic and decomposer pathways and through soil

Nitrogen cycle

Several “exchange pools”, including the atmosphere, surface water, soil, organisms

The atmosphere is ~78% Nitrogen. Becomes available and “moves” when either “fixed” to NH4 available to plants (and ultimately) other organisms [accomplished by cyanobacteria \n and soil and/or nodule bacteria] or…

converted to nitrates [created from NH4 by nitrifying bacteria or from air through lightning/cosmic radiation]

Carbon cycle

Several “exchange pools”, including the atmosphere, surface water, sediment, soil, organisms. \n Reservoirs include deep ocean, rocks, and fossil fuels

Carbon “moves” in several ways…

CO2 (and water) converted to carbohydrates and O2 through photosynthesis by plants, etc

Once in biotic community, cycles through the trophic and decomposer pathways.

Respiration by organisms (incl. us) creates CO2 which cycles back to atmosphere

Eutrophication

caused by excess nitrogen and phosphate pollution (agricultural run-off, sewage, etc.). \n Can lead to algal blooms and microbial blooms. Increased algal/microbial growth results in low oxygen and sometimes increased toxins– Dead Zones (e.g., “red tide”).

Threats to water cycle

In some areas experiencing drought and/or high demand on water (e.g., American West and southern FL), groundwater and aquifers are becoming depleted faster than recharge

threat to phosphorous cycle

Phosphorus naturally is limiting resource for plants, though some human activities \n (sewage run-off, fertilizers, detergents) can \n increase its availability

threats to nitrogen cycle

Humans release a lot of N and NOx (fertilizers, industry). Can accumulate in air and cause destruction of good ozone in stratosphere and accumulation of bad ozone in air we breathe, acid rain, and greenhouse gases +/or in water and cause eutrophication and dead zones

threats to carbon cycle

More CO2 is being released into atmosphere than is being removed \n (due primarily to burning fossil fuels)

Urban sprawl

low density development – especially leads to the loss of natural habitats.

predicted to lead to loss of ~2 million hectares \n  arable land/yr

spatial footprint has expanded at a higher rate than \n  urban populations

cities have disproportionate impact on biodiversity \n  in part because we build in attractive places

Urban areas contribute significantly to climate change and are responsible for over ____ of global carbon emissions

75%

____ has been identified as the most common natural risk across more than 1,600 cities, each with over 300,000 inhabitants

Flooding

___ are considered the second most hazardous urban risk, affecting 411 million people worldwide.

Droughts

Accounting for all potential disruptions to economic activities, ___ of GDP in cities is currently estimated to be at risk from biodiversity and nature loss.

44% of GDP ($31 trillion)

“nature-positive design”

Healing or resetting our relationship with nature requires a brighter paradigm of urban development

Nature-based solutions for infrastructure are __ cheaper than grey alternatives and deliver _ greater added value in terms of direct and environmental benefits

50% and 28%

10 basic principles of smart growth

Mixed land use (mixes recreation, education, retail, and business)

Compact building design (multistory buildings to protect open space)

Various housing options (housing for all incomes)

Walkable neighborhoods (less cars=less emissions)

Attractive communities (sense of place ex. french quarter)

Preserve farmland and natural resources (opportunities for recreation)

Direct development (revitalize existing neighborhoods)

Transportation choices (public transit)

Cost effective

Stakeholder collaboration (encourages community)

Transit-oriented development (TOD) is an example of smart growth

Principles:

•Provide rapid, convenient, and affordable public transport

•Promote active non-motorized modes of transport

•Manage/reduce private vehicular use

•Provide mixed-use development of neighborhoods and higher efficiency buildings

•Provide active and lively public spaces

•Promote community participation and social connections

Promote local businesses

(ex. Guangming, China and San Diego)