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BIOLOGY EOC REVIEW
Name:
Photosynthesis
1. Identify inputs and/or outputs of matter and/or energy in photosynthesis using words and/or
chemical formulas
Inputs are carbon dioxide/CO2, water/H20, light energy; outputs include glucose/C6H12O6,
oxygen/O2)
2. Describe the rearrangement of atoms during photosynthesis using the chemical equation for
photosynthesis.
3. Explain the role of photosynthesis in the life of plants
Photosynthesis produces sugars for the plant that they use for food or for energy to carry
cellular processes.
4. Explain the role of photosynthesis in the life of animals
Animals (consumers) depend on plants for survival
Reflective questions:
1. What is the big picture of photosynthesis? What are the inputs and outputs? What is the equation
for photosynthesis? What is the purpose of photosynthesis?
Upper trophic levels (consumers) depend on photosynthetic organisms (producers) for survival, not
only for food, but also for oxygen released during photosynthesis.
2. What factors might impact photosynthetic processes?
Light and temperature
3. What are the characteristics of photosynthetic organisms? What organelles do they all have?
They are all heterotrophs, they contain a pigment called chlorophyll that is in the chloroplasts and
that is able to transform energy from the sun into glucose for the plants (light energy into chemical
energy)
4. How is photosynthesis similar to and different from cellular respiration?
They are both opposite processes. Photosynthesis uses energy, cellular respiration releases
energy.
Respiration
1. What is the big picture of cellular respiration? What are the inputs and outputs (both matter and
energy)? What is the equation for respiration? What is the purpose of respiration?
Inputs: Glucose and oxygen
Outputs: Energy (ATP), Carbon dioxide and water
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2. How is it that carbon is an atom that allows organisms to both store and release energy?
Cellular respiration allows organisms to use (release) energy stored in the chemical bonds of
glucose. The energy in glucose is used to produce ATP. Cells use ATP to supply their energy needs.
Cellular respiration is therefore a process in which the energy in glucose is transferred to ATP. The
carbon atoms of the sugar molecule are released as carbon dioxide (CO2).
3. What examples of energy storage and release can you describe in your everyday life?
Large carbon containing compounds are broken into smaller carbon compounds as chemical energy
is transformed to different forms of energy in both cellular respiration and combustion of fossil
fuels.
4. How is a forest fire an analogy for cellular respiration?
In both processes a large carbon containing molecule is combine with oxygen and carbon dioxide
and water (and energy) are released
5. What factors might affect the process of cellular respiration?
Amounts of food (glucose) and oxygen available
6. What are the characteristics of organisms that undergo anaerobic respiration?
Unicellular organisms like bacteria, yeasts, and some prokaryotes undergo anaerobic respiration (in
the absence of oxygen). It can also occur in muscle cells
Cells
1. Describe the essential function(s) of structures within cells (i.e., cellular membrane, cell wall,
nucleus, chromosome, chloroplast, mitochondrion, ribosome, and cytoplasm).
Cellular membrane: Regulates the transport of substances in and out of cell. Protects the cell.
Cell wall: In plants, made of cellulose, it gives rigidity to plant cells.
Nucleus: Control center of cell. In houses the DNA.
Chromosome: Supercoiled DNA structure inside the nucleus.
Chloroplast: In plant cells. Organelle where photosynthesis happens.
Mitochondrion: Power house for cell. Produces ATP.
Ribosome: Makes proteins.
Cytoplasm: Holds all the organelles. Space between nucleus and cell membrane.
2. What is the structure of a cell membrane? What molecules does a membrane contain?
The phospholipid bilayer
Phospholipids and proteins
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3. How does the structure of the cell membrane support its functions?
It allows certain substances to go through the phospholipid bilayer by simple diffusion and
larger or polar molecules through the transport proteins
4. What is the difference between active transport and passive transport?
In passive transport, particles go through transport proteins from higher to lower concentration
and without expenditure of energy.
In active transport, particles move through plasma membrane from lower concentration to
higher concentrations (against diffusion gradient) requiring energy.
5. What is facilitated diffusion and give examples in the human body?
Transport of large molecules through proteins in the plasma membrane. An example would be
sugars molecules like glucose
6. Describe the importance of osmosis.
Osmosis or the diffusion of water through a plasma membrane is fundamental in the regulation
of solutes (dissolved chemicals) inside and outside of the cell. Water will always flow to more
concentrated areas to maintain solutions at equilibrium (equal concentrations)
DNA, Genes, and Protein synthesis
1. Describe the structure of DNA molecules in terms of the four nucleotides. Draw and label.
2. What is the function of DNA? How is information stored in DNA?
To code for proteins
3. Describe the relationships among DNA, chromosomes, genes, amino acids, proteins, and/or
traits.
The amino acids are the monomers or building blocks of DNA. Genes are specific regions of DNA
that code for specific proteins. Each protein determines a trait (hair color, height, etc.).
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Chromosomes are supercoiled DNA structures that are only visible in the nucleus of the cell
when it is about to divide.
4. Describe that the sequence of the nucleotides in a gene specifies the amino acids needed to
make a protein.
Each gene is formed by a sequence of nucleotides each with a base (T, A, G, or C). Every three
bases form a codon. And each codon determines an amino acid. There are only 20 amino acids.
5. Describe inherited traits and cell functions as primarily determined by the proteins expressed by
genes.
Inherited traits like hair color, hair color, height, etc., are determined by the proteins that have
been translated from a specific gene. The same is the case for traits that are not physically
observable, like the production of hemoglobin, the protein that binds to oxygen and transport it
throughout the body in the red blood cells.
6. Predict the complementary strand of mRNA given the nucleotide sequence in a single strand of
DNA.
AATGCAG
UUACGUC
7. What is the relationship between DNA, chromosomes, genes, amino acids, proteins, and traits?
Same as question 3
8. Describe the steps and/or structures in the process by which gene sequences are copied to
produce proteins
mRNA is transcribe from DNA in the nucleus of the cell. Before the mRNA leaves the nucleus,
introns (non-coding regions of DNA) are removed and exons are spliced together. The mRNA
leaves the nucleus and joins the ribosome in the cytoplasm. tRNA’s, with an amino acid at one
end and the three base anticodon at the other end, join the codons in the mRNA inside the
ribosome. The amino acids on the tRNA’s attach to each other as they enter and leave the
ribosome forming a polypeptide chain that will become a protein after further transformations.
Chemical Reactions in Cells
1. What are two reasons that large biomolecules are broken down into smaller biomolecules in
organisms?
To provide energy or building blocks (i.e., proteins into amino acids, carbohydrates into simple
sugars, fats into fatty acids, DNA into nucleotides).
2. What are the subunits that the following molecules made from or broken down into:
a. Proteins – amino acids
b. Fats – fatty acids
c. Carbohydrates – simple sugars
d. Nucleic acids (DNA) - nucleotides
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3. Explain how enzymes break large food molecules down into smaller molecules and how these
molecules become available for the cell to make new molecules.
A chemical digestion process called enzymatic hydrolysis can break the bonds holding the molecular
‘building blocks’ within the food together. For example, proteins are broken down into their
‘building block’ amino acids. Once released, these small molecules can then be absorbed through
the gut wall and into the bloodstream.
4. Describe how the new molecules are different than the original large molecules?
For example a lactose molecule that was broken down into two monosaccharaides: galactose and
glucose.
5. Describe how a cell can be built from the new molecules mentioned in question 3.
The smaller molecules obtain from broken down food molecules are the monomers that make up all
living things (Monosaccharaides, lipids, amino acids).
6. Use a model to explain why it requires a different enzyme to break a molecule apart than it did to
put the molecule together.
For instance the enzyme lactase, that breaks apart the sugar present in milk (lactose) during
digestion is differently shaped and has a different active site than the one that puts together lactose.
7. What are the molecules that transfer energy for cell processes?
ATP, fat, and carbohydrates.
Enzymes and Other Proteins
1. What information do genes carry?
Information to make enzymes and other proteins
2. What are three types of proteins?
Enzymes
Transport proteins
Structural proteins
3. How are cellular processes (like cell division, metabolism, cell growth) regulated in the cell?
Cells use chemicals (like certain proteins and other molecules) to communicate for instance when
the cell need to divide or to die, or when the cell needs to speed up its metabolic rate.
4. How can a signal from the outside world change a gene’s expression?
It is called epigenetics. Environmental factors like smoking tobacco, too much sun, etc. can turn on
or off certain genes that will change what proteins are produced.
Chromosomes and Mitosis
1. Describe the overall process of mitosis. Address why mitosis occurs, in what types of cells it occurs and
chromosome numbers for parent and daughter cells.
Mitosis is necessary for growth or cell repair. It occurs in eukaryotic cells. The original cell starts with a diploid (2
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n) number of chromosomes and ends with two diploid daughter cells.
1. Interphase: The cell grows to its mature size, makes a copy of its DNA, and prepares to divide into two cells.
2a. Mitosis: Prophase: The chromatin in the nucleus condenses to form chromosomes. Structures called spinle fi
bres form a bridge between the ends of the cell. The nuclear membrane breaks down.
2b. Mitosis: Metaphase: The chromosomes line up across the center of the cell. Each chromosome attaches to a
spindle fiber at its centromere, which still holds the chromatids together.
2c. Mitosis: Anaphase: The centromeres split. The two chromatids sperate. One chromatid moves along the spin
dle fiber to one end of the cell. The other chromatid moves to to the opposite end. The cell becomes stretched o
ut as the opposite ends pull apart.
2d. Mitosis: Telophase: The chromosomes begin to stretch out and lose their rodlike appearance. This occurs in t
he two regions at the ends of the cell. A new nuclear membrane forms around each region of chromosomes,
3. Cytokinesis: The cell membrane pinches in around the middle of the cell. Eventually, the cell pinches in two. E
ach daughter cell ends up with the same number of identical chromosomes and about half the organelles and cy
toplasm.
2. Using two pair of homologous chromosomes (2 long and 2 short), diagram the four stages of mitosis:
prophase, metaphase, anaphase, and telophase.
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3. Diagram how DNA replication occurs and mention why DNA replication is an essential part of the cell cycle.
The genetic material needs to duplicate before cell division so the same genetic information is passed on to
the new daughter cells.
Meiosis, Fertilization and Offspring Variation
1. How do sex cells differ from regular body cells?
They have half the number of chromosomes.
2. How are male and female sex cells different from each other?
Female gametes have two X chromosomes. Male sex cells have one X and one Y chromosomes.
3. How do sex cells become regular cells?
When the egg is fertilized by the sperm and the zygote (the fertilized egg) becomes a regular or
diploid cell.
4. How is the genetic blueprint that makes you who you are transferred faithfully from one cell to the
next?
Through each step in the cell cycle there are checkpoints that make sure that all the necessary
sequential requirement during cell division are happening correctly.
5. Why are the offspring of two parents different than one another?
6. What happens when something goes wrong during meiosis?
Chromosomal disorders can happen, like when homologous chromosomes do not separate during
first meiosis which will cause trisomy.
7. How do genetic traits get passed from parent to offspring?
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When the gametes join during fertilization, both the traits from the mother and the father combine
in the zygote (fertilized egg).
8. If two parents are both heterozygous for two traits, what is the chance their offspring be
homozygous recessive for both traits?
1/4
9. How can diseases be passed from parent to offspring?
If these diseases are present in the gametes (sex chromosomes)
10. A cell is about to divide by meiosis. The cell has 6 chromosomes: 2 Long, 2 medium, and 2 short.
Draw in the combinations of chromosomes that would be in the 4 sex cells (sperm or egg) after
meiosis.
Students should draw all 4 cells the same, each having 1 long, 1 medium, and 1 short chromosome. If
they draw cells that are identical to the original, then they don’t understand that meiosis reduces the
genetic information by half. If they don’t draw 1 of each kind of chromosome (1 long, 1 medium, and 1
short), then they don’t understand the matching of homologous pairs during meiosis.
11. If flower color is an incomplete dominant trait, explain how many colors could be present in a
population of plant.
There would be three possible colors. Two of the colors would be for the dominant (CC) and
recessive (cc) homozygous plants. The third color would be for the heterozygous plant (Cc), an
intermediate color between the two homozygous plants.
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Transfers and cycles of matter and energy
1. How is carbon important to living things?
2. How does the carbon cycle connect the environment to living things?
3. Trace a carbon atom from a rotting log in the forest to a black bear in the forest.
4. What role does nitrogen play in living things? What are nitrogen sources in the environment?
5. How does energy move from the sun through living things? As energy moves through an ecosystem,
what transformations can be identified?
6. Where and how can energy be stored in living things?
7. How do carbon and nitrogen cycles bring essential elements from the environment to living things?
8. How does each of these cycles link living things to each other?
9. Can these cycles be interrupted? If so, how? And what happens as a result?
Population Density
1. Describe conditions necessary for populations to increase rapidly.
2. List three factors that affect population density.
3. A park has a forested area of about five square miles and is home to two types of squirrels:
Eastern gray squirrels and Douglas squirrels. A recent ecological survey counted 750 Eastern
gray squirrels and 100 Douglas squirrels in the park. Based on the survey, what is the
population density of Douglas squirrels in the park?
4. What is carrying capacity and what happens when it is exceeded?
5. A park squirrel population has increased rapidly in recent years. Describe two possible
conditions that would cause the rapid increase in the squirrel population. Explain how each
condition would make the squirrel population grow rapidly.
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Limiting Factors
1. List factors that limit growth of plant and/or animal populations in a natural ecosystem.
2. A large amount of nitrogen fertilizer is washed into a lake, causing the algae (small
photosynthetic organisms) to grow and reproduce rapidly. Eventually, the algae cover the
surface of the lake and form a thick mat. Explain how the algae growth may affect other
organisms in the lake.
Population Graphs
See worksheets to practice
Biodiversity
1. Describe how biodiversity contributes to the stability of an ecosystem.
Sustainablity
1. What is meant by sustainable development?
2. Two farming practices used to increase nitrogen in the soil as a) use a fertilizer that contains
nitrogen and b) use animal waste to fertilize the soil. Which farming practice is more
sustainable? Why?
3. Describe how the stability of populations in a community is related to the sustainability of
an ecosystem.
Biological Evolution
1. What role do mutations play in genetic variability? Why is genetic variability an essential
component of natural selection / evolution?
2. How does the environment affect the evolution of a species?
3. Why do some offspring survive and others don’t in a changing ecosystem?
4. How can population growth be connected to evolution?
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5. How do the four factors of biological evolution work together for a species to evolve?
6. How does the fossil record reveal information and evidence of evolution?
7. How does DNA reveal information and evidence of evolution?