Biology EOC Review Session
Biology EOC
Test is the second week back in
January!
You will be taking the test during
your regularly scheduled science
class
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5-6 scenarios
40 questions total
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40-45% Cells, Genetics, DNA
30-35% Populations and Ecology
25-30% Evolution
Test-taking Tips
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Go SLOWLY.
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Take your time, READ everything.
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Look at the pictures, charts and
graphs…they are there for a reason.
Pay attention to words in bold or italics.
They are often clues to help you with the
answer.
Vocabulary
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Variables
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Validity
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Manipulated, responding, control
What you did during the experiment
(procedure) to obtain good data (NOT
repeating, recording, calculating or measuring)
making sure equipment is calibrated correctly
for example.
Reliability

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Repeat the experiment, multiple trials, obtain
more data using same procedure
Making sure you have consistent results
Hypothesis

If…then…because format

I predict…reason
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Most importantly you have to
include a reason for your statement.
“Foaming Spuds”
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Conclusion writing practice
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1. Answer the investigative question
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Was your hypothesis supported/rejected
and why
2. Include supporting data from entire
range of experiment (high and low)
3. Explain how data supports or rejects
your answer to investigative question
4. Use scientific explanation to explain
results/trends
“Foaming Spuds” Procedure Re-write

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Create a procedure for a new variable that is
being tested.
Tips when re-writing a procedure…

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Procedure steps are logical and can be easily repeated
by another person
Variables are identified/implied
 Two controls
 Manipulated and Responding variable
Procedure includes information about recording
measurements
Information about repeating trials is included
Includes a validity measure not included in original
procedure…
Macromolecules
“Giant Molecules” (polymers)
Linked together with smaller
subunits (monomers)
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Carbohydrates
Proteins
Fats (lipids)
Carbohydrates
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Compounds made of carbon,
hydrogen and oxygen
Used as a main source of energy for
many organisms
Used for structural purposes
Breakdown of sugars supplies
energy for cell activities
Proteins
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Macromolecules that contain
nitrogen, carbon, hydrogen and
oxygen
Composed of smaller molecules
called amino acids

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20 amino acids found in nature
Each protein has a specific role

Reaction rates, cell processes, form
bones and muscles, transport
substances in and out of cells, fight
disease
Fats (lipids)
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Compounds made of carbon,
oxygen and hydrogen atoms
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Glycerol + Fatty acid = Lipid
Fats, oils, waxes
Saturated and unsaturated
Not soluble in water
Used to store energy
Parts of biological membranes and
waterproof coverings
Osmosis and Diffusion
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Cell Membrane and Cell Wall
regulate what enters and leaves
cells
This occurs during two processes
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Osmosis
Diffusion
Diffusion
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Movement of dissolved
molecules from one side of
cell membrane to another
Particles move from an
area where they are more
concentrated to an area
where they are less
concentrated
Substances diffuse across
a membrane without the
cell using any energy
Osmosis

Diffusion of water
across a selectively
permeable
membrane

Most membranes
selectively permeable
 some substances
can pass through
and others cannot
 Water passes easily
across most
membranes
Cells
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Cell: smallest unit of life
Prokaryotic: no nucleus
Eukaryotic:with a nucleus
Organelle: Specialized structure
that performs important functions in
the eukaryotic cell
Organelles
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Cell Membrane
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Allows passage of oxygen, nutrients,
and wastes in and out of the cell
Provides protection and support
Found in plant and animal cells
Cell Wall
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Protects the plant cell, maintains its
shape, prevents excessive water intake
Found only in plant cells
Organelles
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Nucleus
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Contains all genes (genetic
information), chromatin, chromosomes
and nucleolus
Controls protein synthesis
Found in plant and animal cells
Chromosome
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Tightly coiled strands of DNA and
protein
Organelles
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Chloroplast
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Site of photosynthesis, convert solar
energy to chemical energy
Found only in plant cells
Mitochondria
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Site of cellular respiration (generates
energy)
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Convert chemical energy in food to a form
cells can use
Found in plant and animal cells
Organelles
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Cytoplasm
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Portion of the cell outside the nucleus
Helps to maintain cellular shape
Found in plant and animal cells
Ribosome
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Where proteins are made
Found throughout the cytoplasm
Found in plant and animal cells
Cell Cycle

Cell cycle – The
series of events
that cells go
through as they
grow and divide.

Has three main
parts: Interphase,
Mitotic Phase,
Cytokinesis
Cell Cycle (Mitosis)
Interphase: Cells increase in size and make
new proteins and organelles.
Chromosomes are replicated.
Mitosis: division of the nucleus. Divided into
4 phases.
Cytokinesis: division of the cytoplasm.
**Produces IDENTICAL Cells**
DNA
DNA is a double helix
“twisted ladder”
Sides of ladder made of
sugar (deoxyribose)
phosphate
Rungs of ladder made of
nitrogenous bases
Adenine, Thymine,
Cytosine and Guanine
DNA

Base-Pairing

In a DNA molecule….
Adenine pairs with Thymine
 Cytosine pairs with Guanine
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DNA is made of molecules called:

Nucleotides
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Sugar, phosphate and nitrogenous base
(ATCG)
Protein Synthesis
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Gene: coded DNA instructions that
control the production of proteins
within the cell
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Contain instructions for assembling
amino acids into proteins
Instructions for making proteins comes
from DNA…must first be converted into
RNA to leave the nucleus

DNA can’t leave the nucleus!
Protein Synthesis
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Process that produces protein using
instructions from DNA (gene)
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Uses RNA as an intermediate step
between DNA and proteins
Two parts:

Transcription (nucleus)
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DNA  mRNA
Translation (ribosome)
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mRNA  protein (amino acid sequence)
Genetics
A gene is a section of DNA that forms a
trait (protein).
For example: Hair color, Height, ear
lobes….
Alleles are different forms of a gene.
For example: brown hair, blond hair or
Tall and short.
You get one allele for each trait from
your parents…
Genetics
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Dominant allele – the allele that “wins”. We use
a capital letter “R”
Recessive allele – the allele that is hidden or
loses . We use a lower case letter “r”.
RR = Dominant, Dominant - Homozygous
This person can roll their tongue
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Rr = Dominant, recessive – Heterozygous
(hybrid)
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This person can roll their tongue
rr = recessive, recessive - Homozygous
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This person can’t roll their tongue
Genetics
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Each organism must inherit a single
copy of a gene (allele) from each of
its parents
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Organisms have two copies of each
gene (genotype 2 letters)
Gametes (sperm and egg cells)
each contain one copy of each gene
Cells and Chromosomes
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Diploid: 2 copies of each chromosome
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All cells except sperm and egg cells
Mitosis
Haploid: one copy of each chromosome
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sperm and egg cells only
Meiosis
Humans 46 chromosomes
 Reproductive cells have 23 chromosomes
Meiosis
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What are the differences between mitosis and
meiosis?
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Allows for genetic variation
“Meiosis is the process in which the number of
chromosomes per cell is cut in half”
Mitosis produces two cells; cells are identical
Meiosis produces four cells; cells are unique; occurs
only in sperm/egg cells
What are the similarities between mitosis and
meiosis?
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First phase identical (meiosis phase 1); form of cell
division
Evolution

Evolution – change over time
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It is the process by which modern organisms
have descended from ancient organisms.
 How well an organism is adapted to its
environment
Current scientific facts, observations and
hypotheses all combine to create current
evolutionary theory

a well-supported, testable explanation of the
biological diversity on Earth.
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1.
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Tortoises
longer neck for
sparse vegetation.
Shorter neck where
vegetation was
more abundant.
2. Finches

Darwin noticed that
these birds have
different shaped
beaks, adapted to
their food source
(seeds)
Evidence for Evolution
Fossil Record – transitional
fossils show us
intermediate stages.
Example: horse and camel
Evolution by Natural Selection
Definitions:
1. struggle for existence – members of a
species compete for resources
2. Fitness – ability to survive and reproduce
3. Adaptations – inherited characteristics
that increase an organisms chance of
survival.
Variation
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Caused by mutations (changes in DNA
sequences
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Results in physical or behavioral changes
May be beneficial or harmful
 Increase or decrease survival rates
Inheriting different alleles from parents
(causes individuals to look different)
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Results of meiosis are different every time
Why we don’t look exactly like our siblings!
Photosynthesis and Cell Respiration
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What happens during photosynthesis?
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Plants (autotrophs) use energy from sunlight
to convert water and carbon dioxide into
carbohydrates (energy) and oxygen

6CO2 + 6H2O
(light)
→ C6H12O6 + 6O2
Reactants?
Carbon dioxide (CO2) and Water (H2O)
Products?
Glucose—Sugar (C6H12O6) and Oxygen (O2)
Photosynthesis and Cell Respiration
Cellular respiration… is the process that
releases energy by breaking down food
molecules (glucose) in the presence of
oxygen; occurs in heterotrophs
6O2 + C6H12O6  6CO2 + 6 H2O + Energy
oxygen+ glucose carbon dioxide + water+ energy
Compare this to the equation for photosynthesis….what
do you notice?
Carbon Cycle
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Essential molecule
that makes up all
organisms
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Proteins, fats,
carbohydrates
Carbon is cycled…
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Between the
atmosphere, land,
water and organisms
Short and long-term
cycles
Carbon Cycle
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In an ecosystem…
1. Plants convert carbon dioxide into
carbohydrates (photosynthesis)
2. Consumers eat producers, get carbon
from carbohydrates (glucose)
3. Consumers release carbon to
atmosphere in carbon dioxide
(breathing)
Population Ecology
Population – group of individuals
of the same species that live in
the same area.
 Population Density = #
individuals/area

Population Growth
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Populations may stay constant or change
drastically from year to year.
4 factors affect population size
1.
2.
3.
4.
Natality – birth rate
Mortality – death rate
Immigration – movement of individuals IN
Emigration – movement of individuals OUT
Limiting Factors
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Limiting factors cause population growth to
decrease.
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Density dependent – a factor that depends on
population size. Occurs when populations are
large and dense.
 Competition
 Predation
 Parasitism
 Disease
Density Independent: A factor that affects all
populations in similar ways, regardless of
population size.
 Unusual weather
 Natural disaster
 Seasonal cycles
 Human activity
Exponential vs. Logistic Growth
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Exponential growth –
population grows at a
constant rate…with
unlimited resources this will
occur.
Logistic Growth- occurs
when growth slows or
stops. -The largest
number of
individuals
the
environment can
support is called the
carrying
capacity.
Biomes and Biodiversity
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Biodiversity: the number of
different species living in an
ecosystem
Biomes: Rainforest, Tundra,
Savanna
Sustainability
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Sustainability: using natural resources at
a rate that does not deplete them

Condition in which human needs are met in
such a way that a human population can
survive indefinitely
“The traditional definition of sustainability calls for
policies and strategies that meet society’s
present needs without compromising the ability of
future generations to meet their own needs.”
(epa.gov)
Sustainability Issues in Washington
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Invasive Species
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Non-native species causing ecosystem damage
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Pollution (air and water)
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Hydroelectric Dams
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Overfishing
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Forest Management
Field Study Scenario
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Include method for collecting data
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Imply a consistent sampling strategy
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Identify one manipulated variable
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Multiple measurements, 2 sampling areas
Record environmental conditions
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How often, specific technique for recording measurements
Repeat trials
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What is being measured
Record measurements
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Three conditions to be credited (3 areas)
Identify one responding variable
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“count at the same time every day”
Temperature, weather, etc.
Steps of procedure are logical