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Biology Keystone Exam
Review Powerpoint
Characteristics of Life
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Growth
Reproduction
Uses energy (metabolism)
Responds to stimuli (changes)
Change over a long period of time
Definite form, limited size (cells)
Limited lifespan (death)
Scientific Method
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1. Define the problem
2. Make a hypothesis
3. Experiment
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Variable – the part that changes
Control – the part that remains constant
Gather data (results)
Make a conclusion (was my hypothesis
supported or not)
Cells
• Although cells can be very different, all
of them have a few common
characteristics:
1. All have cytoplasm
2. All have a cell (plasma) membrane
3. All need ATP (energy)
Types of Cells
• Prokaryotic cells – small, simple cells
that have no nucleus or membrane
bound organelles (ex: bacteria)
• Eukaryotic cells – larger, complex cells
that have a nucleus and many other
membrane bound organelles (ex: any
living organism except bacteria)
Cell Structures (Organelles)
• Cell Membrane – controls what goes in
and out of the cell
• Nucleus – control center of a cell
• Cytoplasm – “jelly-like” substance that
supports other organelles and gives
cell its shape
• Mitochondria – makes energy or ATP
• Endoplasmic Reticulum – moves things
throughout the cell
More Organelles
• Vacuole – storage container
• Golgi Body – makes and puts things in
vacuoles
• Ribosomes – make proteins
• Nucleolus – controls protein making
• Nuclear Envelope – controls what goes
in and out of the nucleus
• Lysosomes – contain digestive
enzymes
Even More Organelles
• Centrioles – only in animals, helps with
cell division
• Cell Wall – only in plants, gives strength
and support
• Plastids – only in plants, contain
pigments
• Central Vacuole – only in plants, stores
water
• Starch Grains – only in plants, stores
energy
Biological Structures
• Regardless of the structure, from cells to
complex organs, the anatomy (structure) is
directly related to its physiology (function).
• Ex: the heart is a very strong muscle
because it has to pump blood all through the
body
• Ex: the ER is a fluid filled system of tubes in
the cell, it carries materials from one place to
another inside the cell
Water
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Essential for life because of unique
properties:
1. Adhesion – sticks to other things
2. Cohesion – sticks to itself
3. Hydrogen Bonding – water is polar
(has charged regions) which causes it
to stick to itself and other polar things
Water Continued
• It is also important for life because it
has a relatively low freezing point and
changes temperature slowly (high
specific heat)
Organic Chemistry
• All organic molecules contain carbon.
• It is important because it has 4 valence
electrons and likes to form 4 bonds
• Many times it will form bonds with
itself, making long chains
• Polymers – a large macromolecule
made of repeating pieces called
monomers
• Most organic molecules are polymers
Formation and Breakdown of
Polymers
• Dehydration synthesis – monomers are
put together to make a larger molecule
and a water molecule is created
• Hydrolysis – water is added to a
polymer to break it into it’s monomers
Carbohydrates
• Made of C, H, and O.
• Monomers are called monosaccharides
• They are the body’s main source of
energy
Proteins
• Usually made of C, H, O and N
• Monomers are called amino acids
• They make up most of the body that is
not water
• Special proteins called enzymes make
reactions happen more efficiently and
quickly in the body
• Don’t forget protein structure!
Lipids
• Made of C, H and O
• Monomers are called fatty acids
• They function for energy storage and
connecting certain body parts
Nucleic Acids
• Made of C, H , O, N and P
• Monomers are called nucleotides
• They direct the actions and
construction of the entire body
Energy
• All organisms need energy (ATP)
• Organisms have various methods of
obtaining it.
Heterotrophs
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Organisms that eat to live
Herbivores – eat producers (plants)
Carnivores – eat other consumers
Ominvores – eat both producers and
consumers
Autotrophs
• Organisms that make their own food (don’t
need to eat)
Photosynthesis
• Photosynthesis takes place in the
chloroplasts
H2O + CO2 + Light  C6H12O6 + O2
• Energy transfer steps:
1. Light energy is transferred to electrons
2. Electrons flow (electrical energy) through
the electron transport chain
3. Energized electrons are put into glucose
(chemical energy)
Respiration
• Respiration has two steps
• Glycolysis is always first and happens
in the cytoplasm
• Depending on the organism, one of two
types of respiration can follow
Anaerobic Respiration
• Respiration that uses no oxygen
• It’s not very efficient
• 2 types, lactic acid fermentation and
alcoholic fermentation
Aerobic Respiration
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Uses oxygen to make ATP
Also known as the Krebs Cycle
Very efficient
Takes place in the mitochondria
ATP
• Have 3 high energy bonds to the
phosphate
• Gives energy for use in the cell when a
bond is broken
Crossing the Membrane
• The cell membrane is also known as
the phospholipid bilayer
• Some things cross easily, others do not
• Small, lipid soluble things will cross
easily as long as the concentration
gradient is correct
Passive Transport
• Things cross the membrane without
ATP
• Always moves things from high
concentration to low concentration
• Diffusion and osmosis are examples
Active Transport
• Things cross the membrane using ATP
• Can move large things and from low to
high concentration
• Uses a protein in the membrane
Mitosis
• The division of somatic cells (normal body
cells)
• Daughter cells have the same number of
chromosomes as the parent cell
• Errors can lead to cancer
• Look over stages
Meiosis
• The division of gametes (reproductive
cells)
• Daughter cells have half of the number of
chromosomes as the parent cell
• Look over stages
DNA
• Deoxyribonucleic acid
• Has four bases, A, C, G and T
• A and T bond together and G and C bond
together
• Contains the directions for making protein
RNA
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Ribonucleic acid
Made from DNA
Used directly to make protein
mRNA is the actual directions or blueprint
tRNA carries amino acids
rRNA is part of the ribosome (makes
protein)
Replication
• Making new DNA from an old strand
old strand
GATACCA
new strand CTATGGT
Transcription
• Making RNA from DNA
DNA
RNA
CGTACATTCT
GCAUGUAAGA
Translation
• Making protein from RNA
• Find AUG (start codon) first
RNA
GCAUGUAACT
Protein
methionine
stop
Genetics
• Gregor Mendel – monk who discovered
most of what we know with his pea plant
experiment
• Known as the father of modern genetics
Genetics Terms
• Dominant – a gene that always has an
effect (only need one copy); BB or Bb
• Recessive – need two copies to have an
effect; bb
• Genotype – the genes an organism has for
a trait
• Phenotype – the physical trait an organism
has (determined by the phenotype)
More Terms
• Homozygous – having two of the same
genes (BB or bb)
• Heterozygous – having two different genes
for a trait (Bb)
• Briefly look over Punnett squares and
pedigrees
Taxonomy
• Old system – Aristotle – only had two
kingdoms (plants and animals)
• New System – Carolus Linnaeus
• Based on Latin, also developed scientific
names
• System has 7 levels: Kingdom, Phylum,
Class, Order, Family, Genus and Species
5 Kingdoms
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Monera – bacteria
Protista – algae and protozoans
Fungi – mushrooms, mold, yeast
Plantae – plants
Animalia - animals
Domains
• Some scientists argue that there should be
two larger levels of classification called
domains:
1. Prokarya – domain with prokaryotic
organisms in it
2. Eukarya – domain with eukaryotic
organisms in it
Homeostasis
• Inner balance
• Maintaining internal conditions within limits
acceptable for life.
• Ex: keeping your body temperature
between 94 and 105 degrees F
Evolution
• Needed after spontaneous generation was
dicproved by Redi and others
• Lamarck developed the first widely
accepted theory; had two parts
– Organisms develop traits through the use or
disuse of body parts
– Traits gained in the parents lifetime are
passed on to offspring
Darwin
• Sailed on the HMS Beagle to the
Galapagos Islands
• Studied finches in detail; theory has four
parts
-Overproduction (extra offspring)
-Competition
-Variations
-Survival of the fit
Darwin’s Conclusion
• 1. Organisms that are closely related
share a common ancestor somewhere in
the recent past.
• 2. All organisms share common ancestry
if you go far enough back in the fossil
record.
Genetic Drift
• Changes in allelle frequency. Think
peppered moths!
• Can be influenced by mutations (random
changes in DNA).
Geographic Isolation
• Physical separation of two populations of a
species.
Reproductive Isolation
• When two groups of a species are no
longer able to reproduce with one another.
Genetic Isolation
• When previously reproducing groups are
prevented from exchanging genes.
Predation
• One organism eats
another. One
organism benefits,
the other is harmed.
Competition
• Two organisms compete for a limited
resource. Both organisms are
adversely affected.
Parasitism
• One organism
benefits, while the
other is adversely
affected.
Mutualism
• Two organisms live
together and both
benefit.
Commensalism
• Two organisms live
together, one
benefits while the
other is not affected.
Anatomy and Physiology
• Anatomy – the study
of something’s
structures.
• Physiology – the
study of something’s
functions.