Biology Review
Take out your first nine weeks
study guide.
First Semester Review
Experimental Design
• In a controlled experiment only ONE variable can change.
The one variable that changes is called the
• Independent variable.
• Which variable is the result of the experiment?
• Dependent variable
• Which group includes the independent variable?
• Experimental group
• Which group does NOT include the independent variable?
• Control group
• Why is a control group needed?
• To have something to compare the results to.
When graphing…
• Remember DRY/MIX
• Dependent/responding on the Y axis
• Manipulated/independent on the X axis
Symbols
Microscopes
• How do you figure total magnification?
• Eyepiece X objective
• What is the FIRST part of the microscope you
should adjust? Why?
• The diaphragm b/c it controls the amount of
light that enters the microscope.
• Why do you cover a microscope?
• Keep dust away
Chemistry…
• What type of chemical bond occurs when
electrons are shared?
• Covalent – ex: water
• What type of chemical bond occurs when
electrons are transferred?
• Ionic – ex: NaCl, NaBr, CaCl
• When an atom gains electrons it becomes –
• A negatively charged ion
• When an atom looses electrons it becomes• A positively charged ion
Chemistry…
• pH means potential of Hydrogen
• What type of solution produces H+ ions and is
found below 7 on the pH scale?
• Acids
• What type of solution produces fewer H+ ions
and is found above 7 on the pH scale?
• Base or alkaline
• What type of substance reacts with strong
acids or bases to prevent sharp, sudden
changes in pH?
• buffers
Properties of Water…
• Polar covalent bonds are what holds a water
molecule together.
• What kind of bond is found between water
molecules and makes water extremely cohesive?
• Hydrogen bonds
• Cohesion is water sticking to water. Cohesion gives
water surface tension, which is what allows insects
to be able to walk on water.(paperclip)
• Adhesion is water sticking to other substances.
• Water is the universal solvent.
• Water has a high specific heat.
Organic Molecules…
• Contain CARBON.
• All living things contain carbon.
• THE ELEMENT AROUND WHICH ALL LIFE
EXISTS IS CARBON!!!
Carbohydrates…
• ALL SUGARS AND STARCHES ARE CARBS.
• Living things use carbohydrates as their main
source of energy.
• The monomer of a carbohydrate is a
monosaccharide.
• Examples of monosaccharides are: glucose,
fructose and galactose
• Polysaccharides are many sugars.
• Examples of polysaccharrides are: chitin (cell
walls of mushrooms), cellulose (cell walls of
plants), glycogen (animal starch)
Lipids…
• The monomer of a lipid is a glycerol and three
fatty acids.
• Examples of lipids include: fats, oils, waxes (on
cuticle of leaves), triglycerides and cholesterol.
• Functions of lipids:
– Used by living things as a source of STORED energy
– Cushioning and insulation (blubber in polar bears)
Proteins…
• The monomer of a protein is an amino acid.
• Amino acids are made of a carboxyl group, an
amino group and an R group.
• The sequence of amino acids determines the
protein.
• The R group determines the amino acid.
• Examples of proteins: collagen and enzymes
• Functions of proteins:
– Fight disease
– Repair bone and muscle
– Act as enzymes to speed up chemical reactions
Nucleic Acids…
• The only examples of nucleic acids are DNA
and RNA.
• The monomer of a nucleic acids is a
nucleotide.
• Nucleotides consist of a 5 Carbon sugar, a
phosphate group and a nitrogenous base.
• Functions of nucleic acids are:
– Determines hereditary information
– Passes on genes from one generation to the next
– Carries information to ribosomes to tell them how
to make the proteins
Ecology…
• The scientific study of interactions between
organisms and their environment is called
ecology.
• species  populations  communities 
ecosystems biomes  biosphere
• A species is a group of organisms that are so
closely related that when they mate, they
produce FERTILE offspring.
• Biotic factors: living factors ex: animals, plants,
fungi
• Abiotic factors: non-living factors ex: water,
soil, temperature, sunshine, etc.
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Name some abiotic factors that affect plants.
Sunlight, carbon dioxide, pH
Name some biotic factors that affect plants.
Grazing animals, mold, other bacterial or fungal
diseases
Biological magnification – when a toxic substance
increases in toxicity as it progresses through a
food chain or web.
Who is hurt MOST by biological magnification?
Tertiary consumers (top-level consumers)
Name some things that can cause a deer
population to increase quickly…..
Shorter hunting seasons
Ecology…
• Autotrophs or producers – make their own food
• Heterotrophs or consumers – can not make their own
food.
• A trait that promotes an organism’s survival in nature is
called an adaptation.
• A BEHAVIORAL ADAPTATION that helps bears survive the
winter is …
• Hibernation.
• In each food chain or web, how much energy is passed
from one trophic level to the next?
• 10%
• Who receives the LEAST amount of energy?
• Top-level carnivore
• Who receives 100% of the sun’s energy?
• autotrophs
Ecology…
• What type of organism is a producer that does
not need light to make food?
• Chemosynthetic bacteria
• What shows the relative amount of energy or
matter contained within each trophic level in a
given food chain or web?
• Ecological pyramid
• The total amount of living tissue in a given
trophic level is called
• Biomass.
Ecology…
• Energy flows in one direction from the sun to
autotrophs to heterotrophs.
• Unlike the one-way flow of energy, matter is
recycled within and between ecosystems.
• Elements pass from one organism to another
and among parts of the biosphere through
closed loops called
• Biogeochemical cycles.
• Burning fossil fuels affects the CARBON cycle.
• What is the main type of decomposer?
• bacteria
Nitrogen in the biosphere…
• Nitrogen gas in the atmosphere is converted
into ammonium nitrate by bacteria in the
soil. This process is called
• Nitrogen fixation.
• Ammonium nitrate is converted back into free
nitrogen gas by soil bacteria in a process called
• Denitrification.
Ecology…
• Any time a nutrient limits primary
productivity, it is called a
• Limiting nutrient.
• A series of predictable changes that occur in a
community over time is called
• Ecological succession.
• Ecosystems change over time, especially after
disturbances, as some species die out and
new species move in.
Succession
• Succession that begins in an area where NO soil
exists is called
• Primary succession.
• Ex: after a volcanic eruption
• The first species to colonize barren areas are
called
• Pioneer species.
• What is often the pioneer species?
• Lichen – a symbiotic relationship b/w a fungus
and an algae
• Grasses would be the next population to
populate the area.
Succession..
• Succession that begins in areas where soil
exists is called
• Secondary succession
• Ex; after a forest fire or when a farmer clears
land for farming and then abandons the land
This pond shows what?
What will eventually happen to this pond?
What is the layer of soil in the bottom of
the pond called?
Diversity…
• Diversity means differences.
• Diversity in populations allows them to be
able to overcome bad things, like viruses and
bacterial infections.
• This is true for both plants and animals.
• Think of the bubonic plague. How did
humanity survive?
• What would happen to us if there was no
diversity and an outbreak of a deadly virus
occurred?
Predation
• When an animals stalks, kills and eats another
animal, it is called a
• Predator
• The animal that is eaten is called the
• Prey
• What kind of relationship is this?
• Predator-prey relationship
Ecology…
• Any relationship in which two organisms live
closely together is called a
• Symbiotic relationship.
• There are three types: mutualism,
commensalism and parasitism
Mutualism
• A relationship in which both species benefit is a
• Mutualistic relationship.
• Examples:
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Cleaning stations: ex: cleaner wrasse and grouper
Bee/flower
Sea anemone/clown fish
Acacia tree/ant
Aphids/ant
cattle egret / large herbivore
The Cleaner Wrasse and an eel
Commensalism
• A relationship in which one organism benefits
and the other is neither helped nor harmed is
• Commensalism.
• Examples:
– Barnacles / whale
– Remora / shark
– sea star / worm
– bromeliads / tree
Parasitism
• A relationship in which one organism benefits
and the other is harmed in some way is called
• Parasitism
• Examples:
– Mistletoe / tree
– dog/ tick
– bot fly larvae / squirrel
– worms / animals
Tropical Rain Forest…
Tropical Rain Forest Facts…
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Rains just about every day
Always hot and steamy
No grass on forest floor b/c of thick canopy
Terrestrial biome with the most diversity
Located near equator
Another name is jungle
Lots of vines climbing trees, plants have large
broad leaves so they can collect as much
sunlight as possible.
Tropical Savannah or grassland
• Hot year round
• Has wet and dry seasons
• Compact soil due to enormous herds of large
herbivores
• Has frequent fires during dry season
Desert…
• Driest biome • Animals in the desert must be able to tolerate
extreme differences in temperature.
• It is extremely hot in the day and cold at night
because of the lack of moisture
• Has plants and animals that have adaptations
that allow them to live with very small amounts
of water.
• Ex: Ruby!!! Remember, Ruby gets water from
the food she eats. (Fennec Fox)
• The desert is home to many species of reptiles,
however, there are NO amphibians. Why?
Mojave Desert
• Arizona, California, New Mexico and Nevada
• Each of these states have huge populations of
people.
• What natural resource is the most scarce in
this part of America?
• water
Temperate Forest
• We live in the temperate forest.
• There are many different kind of mammal
species living in the temperate forest.
• Why would an animal NEED to be nocturnal?
• Because it is very hot during the day.
• Think of deer in our biome during June, July
and August….when are they active? Why?
• Think of an opossum… nocturnal…. Short,
stocky body….short ears….prehensile tail
Temperate Forest
Tundra…
• Characterized by permafrost which is a layer
of subsoil that is permanently frozen, even in
summer.
• Permafrost is the reason there are no trees in
the tundra.
• Summers are very short and the temperature
is mild.
• During summer months, the sun never sets.
• Winters are bitterly cold.
• Animals must have adaptations that allow
them to survive in extreme cold.
Temperate Grassland
• Great Plains
• Frequent fires
• Many large herbivores like buffalo (bison), elk
and deer
• Warm summers and cold winters
Cells….
• The smallest unit of structure and function in
living things is a
• Cell
• The thin, flexible membrane surrounding both
plant and animal cells is the
• Plasma membrane
• The tough, ridged, nonliving outer wall
surrounding plant cells is called the
• Cell wall
• Proteins are made by the
• ribosomes
Cells
• A prokaryote has NO nucleus and NO membrane
bound organelles.
• Example: Bacteria
• A eukaryote has a nucleus and membrane bound
organelles.
• Ex: plants, animals, fungi and protists
• Levels of organization:
Cells  tissuesorgans organ systems organism
• Three main parts of all cells: cell membrane,
cytoplasm and genetic material (DNA).
• Storage compartments: stores water, salts, carbs and
proteins…
• Vacuole
• The transport system of the cell is the
• ER or endoplasmic reticulum.
• A specialized storage compartment found in single
celled eukaryotes that collects excess water and quickly
squeezes to expel the water from the body of the
single celled organism…
• Contractile vacuole
• The control center of the cell is the
• Nucleus
• Site of photosynthesis
• Chloroplast
• The cell membrane is made of a double layer of
• Phospholipids.
• What does this picture show?
• phospholipids
• Which cell organelle is the garbage disposal of
the cell?
• Lysosome
• What are two structures used for movement
of single-celled organisms?
• Cilia and flagella
• Name two structures
plant cells have that animal
cells do not have.
• Cell wall and chloroplast
• Which organelle provides ENERGY for muscle
movement and every other process in our
body?
• Mitochondria
• What is the ENERGY molecule?
• ATP – adenosine triphosphate
• The process by which any substance moves from an area of
high concentration to low concentration is called
• Diffusion
• The process by which WATER moves through a semi-permeable
membrane is called
• Osmosis
• 23. hypotonic
• 24. hypertonic
• The only type of movement through the membrane that
requires energy is
• Active transport b/c active transport moves a substance
AGAINST its concentration gradient.
• Endocytosis and phagocytosis are types of active transport that
move large materials into the cell.
• Exocytosis is active transport that pushes materials out of the
cell.
• All forms of active transport require energy in the form of
• ATP!!!! (adenosine triphosphate)
Photosynthesis…
• What is this molecule?
• Where do the bonds need to be broken to
release energy? b/w 2nd and 3rd phosphate
• Energy is released from ATP when a
phosphate group is removed.
Photosynthesis
• The equation is:
Photosynthesis
6CO2 + 6H2O + light  C6H12O6 + 6O2
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Reactants are: carbon dioxide, water and light
Products are: sugar and oxygen
Photosynthesis occurs in the chloroplast of plant cells.
What are tiny pores or holes in the leaves of plants that
allow the plant cells to obtain CO2 for photosynthesis and
the release of O2?
• Stomata – they allow GAS EXCHANGE
• Turn to page 219. Let’s look at questions 9 and 10.
Aerobic Respiration
Aerobic Respiration
• Aerobic respiration is another word for
• Cellular respiration
• In aerobic respiration, one molecule of glucose is
used to produce 36 molecules of ATP.
• The equation for aerobic respiration is:
6O2 + C6H12O6  6CO2 + 6H2O + ENERGY
Anaerobic Respiration
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Also called
Fermentation
Two kinds
Alcoholic fermentation is a process where YEAST
produce alcohol, because there is NO oxygen
present.
• Alcoholic fermentation is the process used by
YEAST to produce beer, wine, and whiskey. Used
in making BREAD!!
• Lactic acid fermentation occurs in muscles of our
body – also used to make cheese and yogurt
The Cell Cycle
Phases of Mitosis…
• Prophase:
– Longest phase of mitosis
– Chromatin condenses into short rod-like
structures called chromosomes.
– Nuclear membrane breaks down
– Nucleolus disappears
Phases of Mitosis…