Final Exam Review
Where does all the energy for an
ecosystem come from? What form is the
energy in?
• All of the energy for an ecosystem comes from the
sun in the form of electromagnetic (solar) energy.
What is the importance of photosynthesis
(in terms of energy)?
• Photosynthesis converts electromagnetic energy,
which cannot be used by most organisms, into
chemical energy, which can be used by organisms.
How does energy move through an ecosystem?
(explain the trophic levels)
• Energy flows in a line through the ecosystem. Energy
from the sun is absorbed by the producers, which
produce their own food through photosynthesis. The
producers are eaten by the primary consumers
(herbivores), which are eaten by the secondary
consumers, which are eaten by the tertiary
consumers.
How does the amount of energy change as it
passes through an ecosystem? Why?
• The amount of energy decreased by 90% as it flows
through an ecosystem. This happens because most
of the energy needs to be used by the individual
organism to carry out their life functions or is lost to
the environment as heat.
• For example, if the producers have 1000 kcal of
energy, the primary consumers would only receive
100 kcal of energy, and the secondary consumers
would only receive 10 kcal of energy, and the tertiary
consumers would only receive 1 kcal of energy
How does the amount of energy passed on to
each trophic level relate to the number of
organisms found at each level? Explain.
• As you move to higher trophic levels, the number of
organisms is less than the level before. This is
because the amount of available energy is less, so it
can’t support as many organisms.
What is the importance of photosynthesis (in
terms of matter/carbon cycle)?
• Photosynthesis takes carbon from the atmosphere
(in the form of carbon dioxide) and converts it,
through chemical reactions, into a form that can be
used by most organisms (sugar).
Why are the bacteria in the nitrogen cycle
important?
• Bacteria in the soil and on the roots of plants convert
nitrogen from the atmosphere into ammonia, which
can be used by most organisms.
How does the Law of Mass Conservation relate
to the carbon and nitrogen cycles?
• The Law of Mass Conservation states that matter can
neither be created nor destroyed, only rearranged
into other forms. It relates to both the carbon and
nitrogen cycles because in both cycles, the matter is
not destroyed, it cycles through the ecosystem in
different forms.
What are the three major rocks that make up
the rock cycle?
• Igneous – made from solidified magma or lava;
• Sedimentary – made from compacted and cemented
sediment
• Metamorphic – made from rocks exposed to heat
and pressure
What is the physical (solid, liquid, gas) and
chemical (metal, rock) makeup of the different
layers?
• Crust – made from solid rock
• Lithosphere – made from the solid rock of the crust
and upper mantle, broken into plates
• Asthenosphere – the plastic-like, soft solid rock layer
• Outer core – made of liquid metal
• Inner core – made of solid metal
Where does convection take place? What role
does it play in the movement of the plates?
• Convection takes place in the asthenosphere.
Convection currents cause the plates of the
lithosphere to move.
What are the three types of plate boundaries?
How do they move?
• Divergent – plates move away from each other
• Convergent – plates move towards each other
• Transform – plates slide past one another
What types of landforms/events happen at
each plate boundary?
• Divergent
• continental/continental: rift valley,
• oceanic/oceanic: mid-ocean ridge;
• Convergent
• continental/continental: mountain range
• oceanic/oceanic: deep ocean trench;
• Transform
• earthquakes
What is subduction? At which type of boundary
does subduction occur?
• Subduction occurs when denser oceanic plates slide
below less dense continental plates, forming a deep
ocean trench. This takes place at a convergent
boundary.
What role does the movement at plate
boundaries play in changing the Earth’s surface?
• As plates move, they stretch, compress and break
the Earth, forming new landforms and surface
features.
What is continental drift? What pieces of
evidence are used to prove continental drift?
• Continental drift is the hypothesis that the plates are
in constant motion across the surface of the Earth.
Evidence of continental drift includes puzzle pieces,
geologic evidence, fossil evidence and climate
evidence.
Why was Wegener’s hypothesis rejected?
• Wegener’s hypothesis was rejected because
he could not explain how the continents
moved.
What is the difference between elements,
molecules, compounds and mixtures?
• Elements – a single atom that cannot be broken
down
• Molecules – two elements that are chemically
combined
• Compound – two or more elements that have been
chemically combined in a set ratio
• Mixtures – two or more substances that are NOT
chemically combined and can be separated by simple
means
Classify each state of matter in terms of shape,
volume, particle motion and attraction between
particles.
• Solid – definite shape and volume, particles vibrate
slowly, very strong attraction between particles;
• Liquid – no definite shape but definite volume,
particles flow past one another, weaker attraction
than between the particles of a solid;
• Gas – no definite volume or shape, move quickly,
very weak attraction between particles.
What causes matter to change states?
• Adding or removing thermal energy will cause matter
to change states.
How is heat transferred between objects?
• Heat is transferred from an object at a higher
temperature to an object at a lower temperature
What is a chemical reaction? What are the signs
of a chemical reaction?
• A chemical reaction occurs when two or more
substances combine to create new substances with
new chemical and physical properties.
• The signs of a chemical change are:
•
•
•
•
•
a gas is produced
a spontaneous color change takes place
an odor is released
a change in energy (light, heat, sound) takes place
a precipitate (solid) is formed
What is the difference between endothermic
and exothermic reactions?
• Endothermic reactions absorb heat, causing the
temperature to decrease.
• Exothermic reactions release heat, causing the
temperature to rise.
How does the Law of Mass Conservation relate
to chemical reactions?
• The Law of Mass Conservation states that matter can
neither be created nor destroyed.
• During a chemical reaction, the reactants are only
rearranged to form the products, and the mass of
the reactants equals the mass of the products.
What are the six characteristics of life?
• Organization – organisms are organized into specialized
structures that help the organism carry out life functions
• Reproduction – organisms must be able to create more
living things
• Growth and Development – organisms grow and develop
as they go through their life cycle
• Response to Stimuli – organisms can adapt and adjust to
their environment
• Homeostasis – organisms maintain stable internal
conditions
• Use of Energy – organisms must gain and use energy to
carry out the life functions
What is a system? Why can the cell be classified as a
system? What are some other systems that the cell
can be compared to?
• A system contains two or more parts that interact to
carry out a particular function, and a change to one
part of the system will cause a change to the system
overall.
• The cell is considered a system because it is made of
different organelles that work together to function
correctly.
• Other systems the cell can be compared to include
the human body, a city and a school
How do the different body systems work
together to allow the human body to function
appropriately?
• The human body I made of cells, tissues, organs and
organ systems that each have a specific function and
work together to keep the body working correctly.
What is the function of the bases that make up
DNA?
• The bases that make up DNA code for particular
proteins that make up cells and body structures.
What are mutations? How can mutations
happen?
• Mutations are mistakes that occur in the sequence of
DNA.
• Mutations can cause proteins to form incorrectly or not at
all.
• Mutations can be caused by bases being added,
removed or duplicated
What information can be determined from a
Punnett Square?
• Punnett Squares show all the genetic combinations
that result from a particular genetic combination.