Biology Midterm Review
Essay section: 5 of the following essay questions will be chosen.
Your responses should include the following:
1. Topic sentences with supporting details
2. Complete sentences
3. Thorough answers (use many details) with a length of about 10-12 sentences.
4. For full credit, use ALL vocabulary given. UNDERLINE each vocabulary word when using it.
1. How are theories made and why are they important? (You have to go through the scientific
method in depth to explain what a theory is) Vocab: experimental method, hypothesis,
independent variable, dependent variable, control, data, analysis, conclusion
2. When a scientist designs a space probe to detect life on a distant planet, what kinds of things
should it measure? (Think about the characteristics of life)
3. Describe the structure and function of the 4 major classes of macromolecules that make up all
living organisms.
4. Why are the cytoplasm, cell membrane, DNA and ribosomes common to ALL cell types? Be
detailed and give examples.
5. What does it mean that ‘phospholipids spontaneously form a lipid bilayer’? Why does it behave
like this? Why is this important for a cell? Include all functions of this membrane.
6. During the winter months, the road crews put salt on the road to help melt ice and snow. Explain
why (using the concept of OSMOSIS) the grass closest to the road is dead and the grass furthest
away is alive. Vocab: hypertonic, hypotonic, equilibrium, osmosis
7. Organism A is an autotroph. Organism B is a heterotroph. Explain how EACH organism RECEIVES
its energy in the form of food (glucose). Be detailed. Then explain how EACH organism breaks
down that food (glucose) to give its cells energy. Be detailed. Vocab: Photosynthesis, cellular
respiration, light reaction, calvin cycle, autotroph, heterotroph, ATP
8. When you get a cut your skin cells must reproduce in order to replace the skin. It is crucial that
every new cell that is made have the same DNA as the rest of your body. Explain in detail how your
body makes sure that every new cell receives the same DNA. Vocab: Mitosis, prophase,
metaphase, anaphase, telophase, cytokinesis, interphase, DNA
9. Explain why you would never look identical to your sibling even though you have the same
parents. Also, explain why this variation is so important to populations. Vocab: meiosis, crossing
over, independent assortment, genetic variation, evolution,
10. What makes water so unique? How is water’s uniqueness related to its structural properties?
Also, why is water essential for all living organisms?
Vocabulary Section: You will be given 25 of the following words to fill in the blank. You will
have a word box that may contain more terms than you need.
 Evidence
 Experiment
 Hypothesis
 Scientific Method
 Scientific theory
 Independent variable
 Dependent variable
 Cell
 Homeostasis
 Organism
 Theory of evolution
 Cell wall
 Endoplasmic reticulum
 Golgi apparatus
 Mitochondria
 Lysosome
 Eukaryote
 Prokaryote
 Nucleus
 Organelle
 ribosome
 Plasma membrane
 Active transport
 Enzyme
 Concentration gradient
 Diffusion
 Osmosis
 Passive transport
 Phospholipid
 Equilibrium
 autotroph
 heterotroph
 photosynthesis
 cellular respiration
 stomata
 chloroplast
 fermentation
 ATP
 Electron transport chain
 Krebs Cycle
 Glycolysis
 DNA replication
 Homologous
 Interphase
 Haploid






Mitosis
Meiosis
Cytokinesis
Spindle fiber
Chromosome
Binary fission
Skills Section: Be able to analyze the following diagrams:
Temperature
O Celsius
10 Celsius
20 Celsius
30 Celsius
40 Celsius
50 Celsius
Reaction Rate
2.5
2.75
3.0
3.75
4.5
1.5
pH
2
4
7
8
10
12
Reaction Rate
0.5
1.5
4.5
5.0
2.5
1.0
Reading Section: Be able to analyze and answer questions from the following article.
Eyes from ions
Scientists use charged molecules to grow eyes in tadpole guts. By Stephen
Ornes / January 18, 2012
A new experiment may seem too odd to be true: Scientists have found a way to grow an
eye in a tadpole’s gut. The view from the third eye is probably unappealing, but the study
shows how electric charges can be used to coax cells to grow in surprising ways. It also offers a new look at a
possible way to regenerate, or regrow, larger limbs. Michael Levin, a biologist at Tufts University in Medford, Mass.,
led the study. He told Science News that people who have lost arms or legs may one day be able to wear a special
device to grow a replacement. The new experiment “opens up a huge door to new therapies in regenerative
medicine using electricity,” developmental biologist Jim Coffman told Science News. Coffman, who works at Mount
Desert Island Biological Lab in Salisbury Cove, Maine, did not work on the new study.
Cells make up every part of an animal’s body, including its eyes and guts. Surrounding a cell is a membrane that,
like the walls of a house, keeps the inside in and the outside out. Ion channels, door-like structures on the
membrane, let molecules called ions enter and exit the cell. Ions carry electric charges, which are responsible for
electricity. When ions travel in and out of a cell, they change its electric charge. The difference between the charge
inside the cell and the charge outside of it is called the membrane potential. Levin and his team focused on the
membrane potential. First, they studied newly formed frog eggs. They found that less than one day after the eggs
started to grow, the membrane potential plummeted (went DOWN quickly) in the cells that eventually grow into
eyes. When the scientists injected chemicals to prevent the membrane potential from dropping, the eyes didn’t
grow. The researchers suspected they’d found a connection between the drop in membrane potential and eye
growth, but they weren’t sure yet.
To test this link, the team turned to cells in the tadpoles’ guts. The scientists inserted into those cells new ion
channels that allowed ions to come and go, which meant the team could control the membrane potential. The
researchers tuned the gut cells to have the same membrane potential as the eye cells. Just as they’d hoped, new
eyes grew in the gut. There’s still much work to be done to understand why electric charges can be used to grow
new eyes in unusual places. “It is very intriguing and very interesting, but of course, the mechanism is not well
understood,” biologist Panagiotis Tsonis told Science News. Tsonis, of the University of Dayton, Ohio, said he doubts
that electrical stimulation could produce similar success when growing new organs from cells in lab dishes.
Scientists used to believe that only certain cells grow into eyes, but the new experiment shows that isn’t the case.
The new study suggests eyes can be grown anywhere on the body (which might inspire your next Halloween
costume).