Download FOURTH QUARTER EXAM STUDY GUIDE I. CHANGE OVER TIME

FOURTH QUARTER EXAM STUDY GUIDE
I. CHANGE OVER TIME
A. Charles Darwin
1. Charles Darwin was a naturalist, a person who studies plants and animals by observing them.
2. Darwin was not the first to develop a theory of evolution (how organisms change across many
generations), but his theory is the one best supported by evidence today.
B. Darwin’s Theory
1. Darwin thought all the Galapagos tortoises shared a common ancestor that came to one of the
islands millions of years ago.
2. Darwin knew that in any species, members of the same species each have slight differences,
called variations.
3. Darwin knew that food is a limiting resource, so members of a species that live in the same area
compete for food.
4. If a variation benefited a tortoise, allowing it to compete for food better than other tortoises,
the tortoise lived longer, reproduced more, and passed on its variations to its off spring.
5. Natural selection is the process by which populations of organisms with variations that helps
them survive in their environments live longer, compete better, and reproduce more than
populations that do not have the variations.
C. Evidence for Evolution
1. Living species that are closely related share a common ancestor.
2. The study of similarities and differences among structures of living species is called comparative
anatomy.
3. Body parts of organisms that are similar in position but different in function are called
homologous structures. The forelimbs of different mammals are examples.
4. If species have homologous structures, this suggests that the species are related.
5. The more similar two structures are to each other, the more likely it is that the species have
evolved from a recent common ancestor.
6. Analogous structures are body parts that perform a similar function but differ in structure. The
wings of flies and birds are examples.
7. The existence of analogous structures indicates that the species are not closely related.
8. Body parts that have lost their original function through evolution are called vestigial structures.
The wings of flightless birds are an example.
9. Studying the development of embryos can also provide scientists with evidence that certain
species are related.
II. MATTER AND ENERGY IN THE ENVIRONMENT
A. What is an ecosystem?
1. All living and nonliving things in an area make up an ecosystem.
2. The living things in an ecosystem are the biotic factors.
3. Sunlight and temperature are examples of nonliving factors, or abiotic factors, in an ecosystem.
B. How does matter move in ecosystems?
1. Many types of matter are used over and over again in the environment.
2. The way water and gases move through ecosystems and are used over and over is called a cycle.
C. The Water Cycle
1. Water continually cycles from Earth to its atmosphere and back again.
2. It involves three processes: evaporation, condensation, and precipitation
3. Evaporation is the process during which liquid water changes into a gas called water vapor
4. Condensation is the process during which water vapor changes into liquid water. Clouds form
because of condensation
5. Precipitation is water falling from the clouds to Earth’s surface in the form of rain, snow,
sleet, hail
D. The Nitrogen Cycle
1. Nitrogen is an important element in proteins, which all organisms need to survive.
2. During the process of nitrogen fixation, nitrogen changes from a gas into a form that organisms
can use.
3. Bacteria in the soil break down dead organisms and animal wastes. Thus, nitrogen returns to
the soil.
D. The Oxygen Cycle
1. The process that is the main source of oxygen in Earth’s atmosphere is photosynthesis.
2. The oxygen cycle involves the change from oxygen to carbon dioxide and back again.
E. The Carbon Cycle
1. All organisms contain the element carbon.
2. Plants and algae absorb carbon dioxide through photosynthesis.
3. Animals add carbon dioxide through respiration.
4. Organisms that make their own food are producers.
a. The process of photosynthesis uses light energy to make food and oxygen from carbon
dioxide and water.
5. Consumers obtain energy by eating other organisms.
a. A herbivore eats only plants.
b. Carnivores are animals that eat other animals.
c. Omnivores eat producers and other consumers.
d. Consumers called detritivores eat dead organisms.
F. Modeling Energy in Ecosystems
1. A food chain is a model that shows how energy flows in an ecosystem through feeding
relationships.
2. When you overlap the food chains in an ecosystem, the result is a food web.
3. An energy pyramid shows the amount of energy available in each step of a food chain.
4. The steps of this energy model are called trophic levels.
5. The bottom layer of an energy pyramid contains producers.
6. The middle layer of an energy pyramid contains consumers that eat producers.
7. The top layer of an energy pyramid contains consumers that eat other consumers
8. Only about 10 percent of the energy in one step of an energy pyramid transfers to the next
higher step.
IV. POPULATIONS AND COMMUNITIES
A. The biosphere is the parts of the Earth and the surrounding atmosphere where there is life. It
includes all the land, water, and ice on Earth.
B. A population is all the organisms of the same species that live in the same area at the same time.
1. Competition is the demand for resources, such as food, water, and shelter, in short supply in a
community.
2. Limiting Factor is anything that restricts the size of a population: sunlight, temperature, food,
shelter, disease, predator, and natural disasters
3. Population Density is the size of a population compared to the amount of space available.
4. Carrying Capacity is the largest number of individuals of one species that an environment can
support.
5. Populations can increase through immigration and larger birthrate than death rate.
6. Populations can decrease through emigration and larger death rate than birthrate.
C. A community is all the populations of different species that live in the same area at the same time.
D. An endangered species is a species whose population is at risk of extinction.
E. A threatened species is a species that is at risk but not yet endangered.
V. INTERACTIONS
A. Habitat is where an organism lives and gets the resources it needs to survive.
B. Niche is what the species does in its habitat to survive
C. Relationships
1. Predator-Prey Relationships prevent populations from becoming too large
a. Predator is an organism that hunts another for food
b. Prey is the organism that is hunted
2. Competition is the demand for resources in short supply in a community
3. Symbiotic Relationships – a close, long-term relationship between two species
a. Mutualism: both partners benefit
b. Commensalism: one benefits and the other is unharmed
c. Parasitism: one benefits and the other is harmed
i. parasite – the species that benefits
ii. host – the species that is harmed
VI. BIOMES
A. DRY BIOMES – receive very little rain
1. Desert: dry with very little rainfall – can be cold or hot, found all over the world
2. Savanna: dry, found in Africa, India and Australia
3. Prairie/Temperate Grassland: dry, found in North America, Russia and South Africa
B. COLD BIOMES – cold
1. Arctic Tundra: cold and desert-like, permanently frozen subsoil – permafrost
2. Alpine Tundra: mountains with cold, treeless frozen landscape
3. Coniferous Forest/Taiga: cold with snowfall – Alaska, Canada, Scandinavia, Russia
C. WET BIOMES – wet weather year-round
1. Tropical Rainforest: warm, humid, rainy, near equator, most diverse
2. Temperate Deciduous Forest: moderate rainfall & humidity, North American, Asia, Europe
D. FRESHWATER BIOMES – low salt concentration – less than 1%
1. Rivers and Streams: water continuously moves in a single direction; found throughout the
world
2. Lakes and Ponds: a standing body of water that is created as streams and rivers empty into
it
3. Wetlands: Marshes, Swamps and Bogs: areas where the land is saturated with standing
water
E. MARINE BIOMES – saltwater; regions that cover about ¾ of the Earth
1. Estuary: where freshwater streams and rivers meet the ocean
2. Beach (Intertidal Zone): where the ocean meets the land; submerged and exposed
3. Coral Reef (Neritic Zone): warm, shallow waters that receive lots of sunlight; barriers
around the edge of the continents
4. Open Ocean/Deep Ocean and Benthic Zone (Ocean Floor): includes cold waters far from
land, sunlight cannot penetrate the benthic zone
VII. SUCCESSION
A. Ecological Succession is the process of one ecological community gradually changing into
another
B. Climax Community is a stable community that no longer goes through major ecological changes
C. Primary Succession is succession in a new area where there is little or no soil – such as on a lava
flow or sand dune
D. Pioneer Species are the first species that colonize new or undisturbed land such as mosses and
lichens
E. Secondary Succession is where existing ecosystems have been disturbed or destroyed – such as
when land is cleared for construction
VIII. HUMAN IMPACTS
A. Pollution is the contamination of the environment with substances that are harmful to life; most
is caused by humans but can also be caused by natural disasters
1. Air Pollution: can cause breathing problems for people, can destroy the ozone layer, can
cause photochemical smog, leads to global warming and acid rain, which kills plants,
destroys buildings and pollutes soil and water
2. Water pollution: comes from many sources including agriculture, industry and people; cities
have sewage treatment plants to purify wastewater draining from homes; runoff can pick up
pollutants including pesticides, herbicides, fertilizers and oils
3. Land Pollution: aside from littering people cause land pollution through farming, industrial
practices and mining; improper storage of wastes can contaminate land and cause damage
or destroy entire ecosystems