Unit 3 Exam Study Guide Flashcards
What is biodiversity?
It refers to the diversity of species on Earth.
What is a species?
A species is a type of organism. Often described as individuals that can reproduce (exchange genetic information) and produce fertile offspring.
_________ of the same _______ look alike because they share a genetic history, but there is a _________.
Individuals, species, variation
Members of different _______ can occasionally ________ and produce ______.
species, interbreed, hybrids
Species can be grouped into larger groups called _____.
taxa
Overall most groups of species are _______ but some more than others.
declining
What are five ways humans are threatening other species?
- Habitat loss (reduction in quality of habitat where species live)
- Invasive species (species not native to an environment can compete with native species for resources)
- Pollution
- Overharvesting (unsustainable hunting, poaching, or harvesting)
- Climate change
Human activities are having an impact on ________.
biodiversity
What is species diversity?
One way to measure species diversity is to count the number of species in an area. This is called species diversity.
What is species richness?
Species diversity is the variety of different species in a particulate place.
Scientists estimate that there are between _________ and ________ species on Earth.
5.3 million, 1 trillion
Only about _______ species have been named.
2 million
__________ varies in different parts of the world
Biodiversity
What are hotspots?
Hotspots are the most biologically diverse and threatened areas on Earth.
Who manages hotspots?
Because hotspots are important for conservation, many are managed/sustained by indigenous communities.
Hotspots cover ___ of Earth’s surface but have over ___ of species.
<1.5%, 30%
_________ are biodiversity hotspots.
Tropical rainforests
Every degree of warming will increase the impacts of ________ on other species.
climate change
What are endemic species?
Endemic species are species that are found in only one area on Earth. Ex. Golden toad
Why are endemic species prone to extinction?
If they disappear from their one area, they will go extinct because they don’t exist anywhere else. (Typically smaller populations).
What are specialist species?
Specialist species make their living in a particular way. Ex. Giant panda, Green sea turtle, Yucca
Why are specialist species prone to extinction?
They can only eat one food or live at a certain temperature or reproduce in a particular place. They don’t adapt easily to changes in the environment.
What are generalist species?
Generalist species tolerate a large range of environmental conditions. Ex. House sparrow, Raccoon
Why are generalist species less prone to extinction?
They thrive around humans: they eat almost everything and adapt to changes in environment.
What are organisms with low reproduction?
They are organisms that take a while to reach sexual maturity. When they reproduce, they have a few offspring at a time. Ex. Sand tiger shark, N. white rhino
What are organisms with high reproductive output?
They reproduce quickly and have many offspring in a litter. Sometimes, they reproduce many times in the same year. Ex. Rat, cockroach
What are examples of animals that have a good relationship with humans?
Swans or house cats
What are examples of organisms that are heavily hunted or in conflict with humans?
Sea otters and elephant ivory
What are seven examples of the types of organisms that are generally doing well:
- Generalists
- Adapt to disturbances
- Have large populations
- Found in many places
- Don’t have predators
- Reproduce quickly
- Benefit from humans
What are five examples of types of organisms that are at risk of extinction?
- Specialists
- Have small populations
- Endemic to particular environments
- Do not reproduce fast
- Sensitive to environmental change
What is extinction?
Extinction means that a species is completely gone. Extinction is a normal process.
What is baseline extinction?
It’s the “normal” ongoing extinction rate.
Throughout the history of life on Earth, new species have ________ and others gone ______.
evolved, extinct
The number of species at any one time is the _______ between ________ (formation of new species) and __________.
balance, speciation, extinction
Occasionally many _____ go ______ at once.
species, extinct
What is a mass extinction?
These extinctions happen across taxa and over a relatively short period of time.
Healthy, intact ecosystems provide us with _______ that sustain and fulfill life.
ecosystem services
What are six examples of ecosystem services?
- Source of food/oxygen
- Clean water
- Protection from extreme weather/flooding
- Pollination and pest control
- Source of medical compounds
- Psychological health
The field of _____________ is focused on protecting ________ and ______ through research and by _________________________.
conservation biology, habitats and species, working with local governments and communities
Suburban lawns are an example of ecological _______.
dead space
Insect populations have declined by _____ in the last few decades due to pesticide use, habitat loss, and climate change.
49%
What is the connection between native plants and insects?
Insects are often specialists and show a preference for native plant species. Insects are food and pollinators for so many other native species.
True or false: Biodiversity is not the only source under threat.
True
What are four important factors of water?
- Human body is 70% water.
- Water fills cells giving them shape.
- Many substances dissolve in water (the content of our cells/blood)
- Many chemical reactions require water (Photosynthesis: CO2+Water –> Sugar+Oxygen)
All living and nonliving matter are made of ________.
elements
An ____ is the smallest unit of matter that exists. They are building blocks for life.
atom
Which three particles are atoms made of?
Protons, neutrons, and electrons.
Each type of atom has a different number of ______.
protons
Atoms join together to form ________.
molecules
Small ________ combine with others to make even larger _________.
molecules, molecules
Everything living and non-living is made of ____ joined together.
atoms
Atoms form _______ by sharing ______ in ___________. These bonds are very strong. They also carry ______.
molecules, electrons, chemical bonds, energy
What is a covalent bond?
Is a chemical bond that involves the sharing of electrons to form electron pairs between atoms.
In water molecules, each __________ atom is bonded to the _________.
hydrogen, oxygen
In water molecules, oxygen and hydrogen share _______ unevenly, so water molecules have __________ on them.
electrons, small charges
What are polar molecules?
Molecules with small charges across them are called polar charges. These molecules have an uneven distribution of charge resulting in one side being positive and the other side negative.
Water molecules ____ together.
stick
In water molecules, the opposite charges are _____ attracted to each other.
weakly
In water molecules, these ____ bonds give water a lot of its _________.
weak, properties
What are hydrogen bonds?
An attraction between two atoms or molecules that already participate in other chemical bonds. (Ex. water molecule being attracted to another water molecule).
True or false: Because water molecules stick together, insects such as water striders can walk on water!
True
Water molecules will also stick to _________.
surfaces
The weak attractions between water molecules also make ______.
ice float
Many substances _______ in water.
dissolve
Water is good at dissolving anything with a ________.
charge
Substances dissolving in water makes it possible for ___________ to dissolve and ________ in your cells.
cellular contents, interact
Substances dissolving in water allows your blood to carry ___________ (food and oxygen) to different parts of your body.
nutrients
Water resists changes in ____________.
temperature
Because of ______ between water molecules it takes a lot of _____ to raise the temperature of water.
weak bonds, heat
What are six reasons why water is important for life:
- Allows for water to go up plants.
- Dissolves nutrients
- Provides structure to cells
- Keeps temperatures constant
- Part of many chemical reactions
- Solid water is less dense than liquid
Water is an ________ molecules.
inorganic
You can divide matter as _______ or ________.
organic, inorganic
What are organic molecules?
They have at least one carbon atom bound to hydrogen. They are molecules that make of living things.
The bonds within _______ molecules hold a lot of _____. They are good ____ (food and fossil fuels).
organic, energy, fuels
What are inorganic molecules?
They are small and don’t have carbon bound to hydrogen. (Ex. O2, CO2, H2O)
True or false: weather and climate are different.
True
What is weather?
Local atmospheric conditions over a short period of time. (Ex. snow storm, thunderstorm, heat wave)
What is climate?
Patterns in regional atmospheric conditions (average temperature/precipitation) over a long period of time.
Global temps are often reported as ________ from the average.
anomalies
What are three main factors that determine Earth’s temperature?
- The amount of solar radiation.
- The albedo (reflection) effect.
- The chemistry of the atmosphere. The atmosphere contains different gases that trap some of the Sun’s heat.
What is the Greenhouse Effect?
Greenhouse gases (GHG) are gases in the atmosphere that trap heat.
What are four different types of greenhouse gases in our atmosphere?
- Carbon dioxide (CO2)
- Water (H2O)
- Methane (CH4)
- Nitrous oxide (N2O)
___ is a key component of the Earth’s thermostat.
CO2
If you increase the level of ___ (or other __________) in the atmosphere, it has a _______ effect on the Earth.
CO2, greenhouse gases, warming
Balancing __________ levels in the atmosphere are important to our climate.
current greenhouse
What are the two patterns that emerged affect the amount of CO2 in the atmosphere?
Seasonal variation and overall increase in CO2
Plants remove ____ from the atmosphere during __________.
CO2, photosynthesis
In photosynthesis, cells take in ________ and convert it to __________.
carbon dioxide, organic sugars
What is the process of photosynthesis?
Carbon dioxide + water + sunlight —-> organic sugars + oxygen
__________ releases ___ into the atmosphere.
Cellular respiration, CO2
In cellular respiration, all cells perform ____________.
cellular respiration
___________ converts energy in organic food molecules into ______________.
Cellular respiration, useful cellular energy (ATP)
What is the process of cellular respiration?
Organic sugars+oxygen—> carbon dioxide+water+ATP+heat
There is a natural balance of CO2 in the atmosphere. It is taken up by living things (______) and released again (___________ and __________).
photosynthesis, cellular respiration, decomposition
There is a ________ correlation between the increase in CO2 and the global increase in temperatures.
positive
We can look at levels of CO2 and other molecules in the atmosphere by looking at…
the trapped air bubbles in ice cores.
We can infer past temperatures by…
looking at the chemistry of water molecules.
For millennia, atmospheric CO2 levels have not been above…
300 ppm
What are four sources of CO2?
- Living things
- Volcanoes
- Ocean
- Fossil fuel use (human activity)
Living things have a different carbon-12 to carbon-13 _____ than oceans and volcanos.
ratio
The number of protons determines the element-carbon has _________.
6 protons
What are two types of carbon atoms?
- Some carbon atoms have 6 neutrons (carbon-12).
- Some carbon atoms have 7 neutrons (carbon-13).
Living things have more ____ in their ________.
C-12, tissues
Fossil fuels are ________ molecules derived from living organisms.
organic
Where are fossil fuels derived from?
- Coal, oil and natural gas deposits buried in the Earth’s crust.
- Derived from the remains of plants that lived millions of years ago.
There is very ______________ that the Earth is getting warmer and that human activities are causing the change; there is no ________.
strong scientific consensus, scientific controversy
There are many solutions to climate change that _______ can decide to pursue.
society
Depending on emissions, by 2100, global temperatures will be _____________ higher than today’s temperatures.
1.8-4 degrees celsius (3.2-7.2 degrees Fahrenheit)
Limiting warming to ___________ will help stave off the more catastrophic effects of warming.
1.5-2 degrees celsius
Limiting warming will require restoring _____ between ________ and _____ (places where carbon is stored).
balance, sources, sinks
Life’s energy comes from the ___.
sun
What are three ways that the sun’s energy reaches the Earth?
- Absorbed by the atmosphere
- Reflected by the atmosphere/clouds
- Some reaches the surface of the Earth
Some of the energy that reaches the Earth’s surface ____________.
fuels ecosystems
What is an ecosystem?
All the organisms in an area, along with the nonliving factors (abiotic) with which they interact.
What is the main way organisms within an ecosystem interact?
One of the main ways in which organisms within an ecosystem interact is by eating or getting eaten.
All organisms need both _______ (to do stuff) and _______ (to build their bodies).
energy, matter
What is energy?
Energy is the ability to do stuff; energy allows cells to carry out life’s functions.
What is matter?
Matter is what organisms are made of; matter is used to build cells.
What are producers?
Producers take energy from the sun and convert it into sugars and other molecules (chemical energy) by photosynthesis.
What are consumers?
Consumers obtain energy by eating producers and other consumers.
Both producers and consumers convert _______ into ________________.
chemical energy, ATP by cellular respiration
What are primary consumers?
Consumers who eat producers are called primary consumers.
What are secondary consumers?
Organisms that eat primary consumers are called secondary consumers.
What are tertiary consumers?
Organisms that eat secondary consumers.
Primary consumers are ____________. Other consumers are _________ or __________.
herbivores, carnivores, omnivores
If you take out a _________, for example by people hunting it down, the loss of the _________ will affect other organisms both ________________.
predator, predator, directly and indirectly
What are trophic (energy) levels?
An organism’s position in a food chain or food web (produce, primary consumer, secondary consumer) is called a trophic level (energy/feeding level).
The trophic level of an organism is the ____________ it is from the start of the chain. (Ex. producers are trophic level 1).
number of steps
Most ecosystems have a maximum of ______________.
4-5 trophic levels
Why do most ecosystems have a maximum of 4-5 trophic levels?
That is the maximum number of trophic levels that the available energy can support.
______ is the ultimate source of energy in most ecosystems.
The sun
As ________ moves from one ___________ to the next, most energy flows out as _____.
energy, trophic level, heat
There is _____ available energy at _______________.
less, higher trophic levels
How is energy passed down in the energy pyramid?
100% (Primary Producers)—>10% (Primary Consumers)—>1% (Secondary Consumers)—>0.1% (Tertiary Consumers)
Where does the remainder of the energy go in the energy pyramid when it’s not passed down to the next trophic level?
It’s lost as heat energy
Which trophic level has the most energy?
Bottom (primary producers) since they gain 100% of the energy from the sun.
What makes up the last part of food chains?
Detritivores and decomposers make up the last part of food chains.
What are detritivores?
Detritivores eat plant and animal remains (ex. vultures eat dead animals; dung beetles eat feces).
What are decomposers?
They are “recyclers” of matter. They break down matter left behind by consumers, including waste, uneaten food, and dead organisms. They break down organic matter into inorganic materials that fertilize the soil.
What are examples of decomposers?
Bacteria and fungi.
Energy ______ through an ecosystem, while matter is _______ in an ecosystem-matter is ________.
flows, recycled, limited
Producers get matter from simple __________.
inorganic molecules (ex carbon dioxide in the air, nitrogen in the soil).
Consumers get matter from _____.
food
Biodiversity tends to increase closer…
to the equator
What are three ways we are working to conserve biodiversity?
- Legislative approaches
- Creating protected areas
- Habitat restoration
What are the three categories of ecosystems?
- Freshwater ecosystems (lakes, rivers, streams)
- Marine ecosystems (shallow ocean, deep ocean water, deep ocean bottom)
- Terrestrial ecosystems (Tropical rainforests, savannas, deserts, grasslands, temperate forests, and tundra)
What are ecosystem disturbances?
Ecosystems are routinely exposed to various disturbances: environmental changes that affect their compositions.
What are two factors of ecosystem disturbances?
- Many disturbances are the result of a natural process.
- Human activities can also cause environmental disturbances.
What is a food chain?
A food chain is a linear sequence of organisms that shows how energy and nutrients pass through an ecosystem as one organism eats another.
What are apex consumers?
They are the consumer that are on the top of the food chain.
What is a food web?
A food web accounts for the multiple feeding interactions between each species.
The ______ in a food web diagram illustrates how energy flows through the ecosystem.
arrows
Energy is acquired by living things in two ways: _______ harness light or chemical energy, and _______________ energy by eating a digesting other living or previously living organisms.
autotrophs, heterotrophs obtain
What are autotrophs?
Plants, algae, and phytoplankton are autotrophs. They convert the light energy from the Sun into food energy by photosynthesis.
______ flows from the Sun through an ecosystem. On the other hand, the ________ (nutrients) that make up living organisms are conserved and recycled in ecosystems.
Energy, elements
Carbon cycling in an ecosystem is most easily described as two interconnected subcycles…
- The rapid carbon cycling among living organisms through photosynthesis/cellular respiration.
- The long-term carbon cycling through geologic processes.
Where is the energy in fossil fuels stored?
Large carbon molecules
What is Anthropocene?
The time during which humans have had a substantial impact on our planet.
What is migratory?
Moving from one place to another at different times of the year.
What is relative abundance?
It refers to the evenness of distribution of individuals among species in a defined location.
What is a solvent?
It’s a chemical that dissolves a solute, resulting in a solution. (Ex. Water)
