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MIDTERM REVIEW QUESTIONS
CHAPTER 1 – THE SCIENCE OF LIFE
Biology - the study of life
Genes - a segment of DNA that is located in a chromosome and that codes for a specific
hereditary trait
Cells - the smallest unit that can perform all life processes; cells are covered by a
membrane and contain DNA and cytoplasm
Homeostasis - the maintenance of a constant internal state in a changing environment
Experimenting - carrying out procedures under controlled conditions to discover,
demonstrate, or test a fact, theory, or general truth
1. How do you determine total magnification on a microscope?
Eye piece magnification (usually 10X) times the magnification of the objective lens.
Ex/ 10 X (eye piece) * 40X (objective lens) = 400 X magnification
2. What are the characteristics of living things?
Organization and cells, response to stimuli, homeostasis, metabolism, reproduction,
growth and development, change over time
CHAPTER 2 – CHEMISTRY OF LIFE
1. Define “atom”
The simplest particle of an element that retains all of the properties of that
element.
2. What are the parts of the atom, their charges and where are they located?
Proton ,(+), nucleus
Neutron (neutral), nucleus
Electron ,(-), surrounding nucleus
3. What’s the difference between an ionic and a covalent bond?
Ionic = electrons are exchanged; Covalent = electrons shared
4. What are enzymes?
A biological catalyst; a protein that speeds up metabolic reactions in cells without
being permanently changed or destroyed
5. Where are acids and bases on the pH scale?
Below 7 = Acid
7=Neutral
Above 7=Base
6.
What is a “buffer” and why are they important?
Buffers are chemical substances that neutralize small amounts of either an acid or
a base added to a solution. They are important because maintain the pH of our
bodies and keep us healthy.
7. Why is water considered to be a polar molecule?
B/C it has unequal sharing of electrons between Hydrogen and Oxygen, results in
side (O) of molecule having slight negative and other part (H) having slight positive
charge
8. Define “element”. Name the top 4 elements in all living things.
Elements are substances that cannot be broken down chemically into simpler kinds
of matter. The 4 top elements in living things are: carbon, hydrogen, oxygen, and
nitrogen.
CHAPTER 3 – BIOCHEMSTRY
1. Associate the following words with their correct class of macromolecule (Carbs,
Proterins, Lipids, Nucleic Acids)
Fats –
LIPID
Sugars –
CARB
DNA –
NUCLEIC ACID
Amino Acids –
(monomer of) PROTEIN
Enzymes –
PROTEIN
Nucleotide –
(monomer of) NUCLEIC ACID
Glycogen -
CARB
1. What is glycogen? In what organism will you find it?
Glycogen is a polysaccharide consisting of hundreds of glucose molecules in a branched
chain. It is found mammals in their liver and muscles.
2. How do plants store their extra glucose?
In the form of starch
3. What are the monomer units (building blocks) of proteins?
Amino acids
4. What are the 2 types of nucleic acids?
DNA & RNA
5. What are the monomer units (building blocks) of nucleic acids?
Nucleotides
6. What are the monomer units (building blocks) of carbohydrates?
Monosaccharides (or simple sugars)
CHAPTER 4 – CELL STRUCTURE AND FUNCTION
1. How did Hooke discover cells?
Looked at cork shavings, saw cube-like structures, called them cells
2. As a cell gets larger, does its surface area increase the same amount as its
volume? Explain your answer….
NO, surface area doesn’t grow as rapidly as volume
3. Why is surface area such an important factor to a cell?
Surface area determines how quickly nutrients can enter and wastes can be
removed – if surface area is not sufficiently large enough for the volume of the
cell, the cell will not efficiently transport substances across its membrane
4. What is the main difference between prokaryotes and eukaryotes? Give an
example of each.
Pro – no nucleus; Example: bacteria
Eu – nucleus: Example; human cells, plant cells etc.
5. What’s an organelle?
Cell parts that are specialized to perform a specific function
6. What three items are found in ALL types of cells?
Cell membrane, cytoplasm, control center (containing genetic information)
7. Fill in the following chart indicating the organelle that matches following
functions:
Organelle
Function
CHLOROPLAST
ENDOPLASMIC RETICULUM
CENTRAL VACUOLE
MITOCHONDRIA
NUCLEUS
Found only in plant cells – used in photosynthesis
Moves materials from one area of a cell to another
Large membrane bound sac where plants store water
Makes energy – ATP
The control center – where chromosomes are found
LYSOSOMES
The recycling centers of cells
RIBOSOMES
Where proteins are made
CILIA
Hair-like organelles on cell surface used for movement
CELL MEMBRANE
Regulates what enters and leaves the cell
8.Label the membrane, nucleus, mitochondria and
cytoplasm on the cell to the right.
cell membrane
Is it a plant or animal cell? ANIMAL
How do you know? NO CELL WALL
mitochondria
nucleus
cytoplasm
13. Classify each of the following organelles as Plant, Animal, or Both:
Nucleus – BOTH
Chloroplasts – PLANT
Mitochondria – BOTH
Cell Wall – PLANT
Endoplasmic Reticulum – BOTH
14. List the correct order of organization of structures in living things, from
simplest to most complex.
ATOM  MOLECULE  CELLS  TISSUES 
ORGANS  ORGAN SYSTEM  ORGANISM
CHAPTER 5 – HOMEOSTASIS AND TRANSPORT
1. Active vs Passive TransportACTIVE
REQUIRES ENERGY REQUIRED
MOVES MOLECULES AGAINST GRADIENT (L H)
SODIUM POTASSIUM PUMP
PASSIVE
NO ENERGY REQUIRED
MOVES MOLECULES WITH GRADIENT (HL)
DIFFUSION, OSMOSIS, FACILITATED DIFF
2. Diffusion - the movement of particles from regions of higher density to regions of
lower density (passive transport)
3. Osmosis - the diffusion of water or another solvent from a more dilute solution (of a
solute) to a more concentrated solution (of the solute) through a membrane that is
permeable to the solvent (passive transport)
4. Facilitated Diffusion - the transport of substances through a cell membrane along a
concentration gradient with the aid of carrier proteins (passive transport)
5. Endocytosis - the process by which materials are brought into the cell (active
transport)
6. Exocytosis - the process by which a substance is released out of the cell (active
transport)
7. What happens when you place animal and plant cells in the following types of
solutions?
Solution
Effect on Plant Cells
Effect on Animal Cells
Hypertonic
Plasmolysis – membrane pulls
away from wall
Cell shrinks
Hypotonic
Becomes turgid – swollen
Cytolysis – cell bursts
Isotonic
Stays same
Stays same
CHAPTERS 6 & 7 PHOTOSYNTHESIS AND RESPIRATION
1. Complete the table below
Photosynthesis
Definition
the process by which plants,
Equation
Organelle it occurs
in
Respiration
algae, and some bacteria use
sunlight, carbon dioxide, and
water to produce carbohydrates
and oxygen
the process by which cells produce
energy from carbohydrates;
atmospheric oxygen combines with
glucose to form water and carbon
dioxide
6 CO2 + 6H2O  C6H12O6 +6O2
C6H12O6 +6O2  6 CO2 + 6H2O +ATP
Chloroplasts
Mitochondria
2. What is the job of chlorophyll in photosynthesis?
Capture solar energy (absorb sunlight) and convert it to cellular energy
3. What are some environmental factors that affect the rate of photosynthesis?
Light intensity
Temperature
Amount of CO2
4. Compare a heterotroph with an autotroph. Give examples of each.
Heterotrophs must obtain energy from food; they cannot make their own food.
Example: humans
Autotrophs use the energy from sunlight to make their own food
Example: plants
5. Explain why chlorophyll is green?
Because chlorophyll absorbs all of the colors from sunlight except green, which it
reflects.
6. Which types of organisms perform respiration (heterotrophs, autotrophs or
both)?
Both
7. Which types of organisms perform photosynthesis (heterotrophs, autotrophs or
both)?
Autotrophs
8. Name three products of the respiration reaction:
6H20 + 6CO2 + ATP
9. Name the 2 types of fermentation and name an organism that performs each
type.
Lactic acid fermentation- bacteria that make milk, yogurt, etc.
Alcoholic fermentation- yeast
10. All fermentation occurs without what material (gas)?
Oxygen
CHAPTER 8 – CELL REPRODUCTION
Binary fission - a form of asexual reproduction in single-celled organisms by which one
cell divides into two cells of the same size
Chromosome -in a eukaryotic cell, one of the structures in the nucleus that are made up
of DNA and protein; in a prokaryotic cell, the main ring of DNA
Chromatid -one of the two strands of a chromosome that become visible during meiosis
or mitosis
Karyotype –a picture of the chromosomes found in an individual’s cells at metaphase of
mitosis and arranged in homologous pairs and in order of diminishing size
Mitosis - a process of cell division that forms two new nuclei, each of which has the
same number of chromosomes
Meiosis - a process in cell division during which the number of chromosomes decreases
to half the original number by two divisions of the nucleus, which results in the
production of sex cells (gametes or spores)
Haploid -describes a cell, nucleus, or organism that has only one set of unpaired
chromosomes
Diploid - a cell that contains two sets of chromosomes
Cytokinesis - the division of the cytoplasm of a cell; cytokinesis follows the division of
the cell's nucleus by mitosis or meiosis Animal - cells pinch in two; vs. Plants – cells
divide by producing a cell plate between two cells
Non-disjunction – when homologous chromosomes do not separate properly during meiosis
I. Or when sister chromatids do not separate properly during meiosis II
1. How can such a large molecule as DNA fit inside of a cell’s nucleus?
It is wound very tightly around proteins into smaller packages
2. Label the phases of mitosis in the diagram below (one is interphase):
INTERPHASE (technically not a mitosis phase)
TELOPHASE
ANAPHASE
PROPHASE
METAPHASE
3. If an organisms diploid (2n) number is 50, what is its haploid (n) number? 25
How many chromosomes after one of its cells goes through mitosis? 50
How many chromosomes after one of its cells goes through meiosis? 25_____
4. A human skin cell has 46 chromosomes – how many pairs are there? ___23_____
How many are autosomes? ___44________ Sex chromosomes? ____2_
MALES = XY; FEMALES =XX
5. How is meiosis I different from meiosis II?
In meiosis I, chromosomes travel as tetrads and crossing over occurs. DNA is not
copied before meiosis II and homologous chromosomes separate during anaphase
II. Each cell produced has half of the genetic information as the parent cell.
6. Briefly describe what happens during each stage of meiosis I:
Prophase I
DNA coils into chromosomes, nucleolus and nuclear membrane
disappear, homologous chromosomes pair up (forming tetrads),
crossing over occurs.
Metaphase I
Tetrads line up along the middle of the cell, spindle fibers attach to
each homologous chromosome.
Anaphase I
Homologous chromosomes move to each end of the cell. Separation is
random (independent assortment) and is a cause of genetic variation.
Telophase I
Chromosomes reach poles of cell and cytokinesis begins.
7. What is crossing over and when in meiosis does it occur?
When homologous chromosomes swap equal portions of DNA. It occurs during
Prophase I (Meiosis I)
CHAPTER 10 – DNA, RNA, AND PROTEIN SYNTHESIS
1. What is the function of DNA? Contains genetic information of the cell and directs
all cell’s activities by directing protein synthesis
2. What are the three parts of a nucleotide? Which part gives the nucleotide its
name?
Nucleotide = sugar (deoxyribose in DNA, ribose in RNA)+ phosphate group
base (A,T,C,G)
Nucleotide name = base name
3. Which bases get paired?
A
T; C
G
4. Who discovered the double-helix nature of the DNA molecule? Watson & Crick
5. Complete the chart below that compares DNA to RNA:
Characteristic
DNA
RNA
# of strands
2
1
Sugar
Deoxyribose
Ribose
Bases
Adenine, Thymine
Guanine, Cytosine
Adenine, Uracil
Guanine, Cytosine
Types
N/A
mRNA, tRNA, rRNA
Where found in cell
Nucleus
Nucleus and in cytoplasm
The following questions refer to the following sequence of mRNA
UUUGCGCCCACU
6. What would the DNA sequence be that this mRNA was made from?
(work backwards)
AAACGCGGGTGA
7. Using the table on page 207 of your textbook – what series of amino acids would
be encoded by the mRNA? (go back to the original strand given – its your RNA to
use in the table)
UUU-GCG-CCC-ACU (from above)
phenylalanine – alanine – proline – threonine
8. Each triplet that codes for an amino acid is called a ______codon_____
9. What cell organelle moves along the mRNA during translations? __ribosome____
10. Complete the following chart that compares the two phases of protein synthesis:
Transcription
Definition
Where it occurs
DNA involved? (Yes/no)
Translation
the process of synthesizing RNA
by using one strand of a DNA
molecule as a template
uses the codons in mRNA
molecules to specify the sequence
of amino acids in polypeptide
chains
Nucleus
Ribosomes
yes
no