BIO 171 - Third Exam - 2018

Multiple Choice.

Place the letter of the choice that best answers the question on the line to the left.
Two Points Each. NOTE: “e” answers are never the correct answer.

_______1. During fertilization,

                a. Diploid cells get together                            b. Haploid cells get together
                c. One diploid cell joins one haploid cell          d. All of these can happen
                                    e. Fertility is, umm, made fertilaceous...

_______ 2. G proteins are involved with

                a. Generating 2nd messengers         b. Activating genes        c. Attaching spindle fibers to centromeres
                d. Silencing genes                                        e. Being amazed a lot

_______ 3. Some hormones attach to receptors well inside their target cell.  Those hormones are

                a. Isoosmotic         b. Being actively transported        c. Steroids         d. Used in respiration
                                                    e. Always on the doorman’s list

_______ 4. A near extinction can produce a

                a. Restriction event             b. Genetic drift             c. Constriction event
                d. Bottleneck effect                     e. Really annoyed species

_______5. Under normal conditions, rare sodium ions move slowly from fresh-water into plant cells,
                                where the concentration is higher. This is done by

                a. Osmosis         b. Active transport         c. Diffusion        d. Passive transport         e. Plant elves

_______6. Watson and Crick’s description of the double-helix structure of DNA was important
                                    primarily because it explained how DNA could

                a. Be mutated                                             b. Be wound up into chromosome structures
                c. Hold a variety of information                    d. Be structured around a carbohydrate base
                                        e. Made into a delicious cotton-candy treat

_______7. Substrates are a type of

                a. 2nd messenger         b. Enzyme         c. Ligand        d. Hormone         e. Underclothing

_______8. The best explanation for why most genetic diseases are recessive involves

                a. Two DNA codes that can’t be used             b. Two DNA codes for non-working proteins
                c. DNA codes that don’t get passed on            d. All of these are involved
                                                e. Explaining what recessive means

_______9. Which best describes plasmids?

                a. Extra genes         b. Extra chromosomes        c. Energy producers         d. Used for secretion
                                    e. Yet another term that I recognize but don’t remember...

_______10. In dividing cells, actual cell division (cytokinesis) occurs

                a. Only in telophase         b. In anaphase or telophase        c. In telophase or interphase
                d. In interphase, telophase, or anaphase        e. When cell parts get really angry with each other

_______11. Which would be an example of chemotaxis?

                a. A person finding the source of a smell       
                b. A plant absorbing nutrients from fertilizer
                c. Chlorophyll moving from a ribosome into a chloroplast
                d. Chromosomes moving toward the middle of the cell
                e. Something involving yellow cars with sticky floors

_______12. Embryo cells have their eventual fates set early in

                a. Plants         b. Protostomes         c. Fungi         d. Deuterostomes         e. Very strict phyla

______ 13. Prokaryotes assure that newly-formed cells get the right chromosome copies by using

                a. Spindle fibers at the poles         b. Linked ribosomes        c. Links between the new cells
                d. Attachment points on the membrane        e. An entire squad of specially-trained inheritance lawyers

_______14. During which parts of mitosis is the nuclear envelope always “missing”?

                a. Metaphase & anaphase             b. Prophase & telophase            c. Interphase only
                d. Prophase, metaphase & anaphase            e. Well, it never seems to be there when the check comes...

_______15. Immune cells often recognize “self” cells by analyzing

                a. Genetic markers         b. Glycocalex        c. Cell junctions         d. Cell projection structures
                                                            e. Credit card receipts

_______16. The growth of multicelled organisms is generally a product of

                a. Cell division only             b. Cell expansion only            c. Cell division and cell expansion
                d. Added noncellular material            e. Consuming some sort of well-advertised breakfast food

_______17. Okazaki fragments exist because

                a. Enzymes digest them for electrophoresis            b. Crossing over produces them
                c. Cell structure is made up of small elements        d. DNA strand replication is limited to one direction
                                                e. Okazaki could never finish anything

_______18. Metamorphosis can

                a. Alter the mutation rate         b. Increase the carry capacity        c. Elimination predation
                d. All of these                                    e. Mess with a critter’s self-esteem

Short Answer.

Pick NINE questions to answer in the spaces provided.
NOTE: if you answer MORE than nine, only the first nine will be corrected.
Four Points each. Partial credit is possible.

1. Briefly explain how a hormone’s effect can be used in a control loop based on negative feedback.

2. What are two different ways that living cell systems can easily increase a material’s flux through the membranes?


3. Other than growth, what two different types of major cell functions occur in interphase?


4. What two areas of well-funded medical research are focused on telomerase?


5. What are two non-selection restrictions on a Hardy-Weinberg population?


6. What are two different ways that living things keep osmotic pressure from hurting them?


7. Give examples of two things whose formation or development would be driven by HOX genes.


8. What are two different types of signal ligands?


9. How is a geotaxis / geotropism produced in a sprouting plant’s stem and root?

10. Of the point mutations, an addition is much worse than a substitution. Explain why.

11. Structurally (with some detail), how is a cell membrane molecule different from a standard lipid molecule?

12. Name two enzymes active in DNA replication.


13. What are two major functions of centromeres?


14. What evolutionary mystery was solved when people looked closely at crossing over?

15. What is one thing that happens in Meiosis I that does not happen in mitosis?

16. For alternation of generations -
A type of
that has it:
Why that
type of organism
has it:

Long Answer.

Select and answer completely any four of the following questions.
Note: if you answer more than four, only the first four will be corrected.
Seven Points Each. Partial credit is possible.

1.  Give three sets of differences (other than the associated genders) between -




2.   What happens in the four “tissue” zones of a fungus?



3.  Give the functions (names are NOT enough) of three different membrane protein types.


4. Fill in for 2 different model organisms



5.   For the four experimental "systems" listed below, give a critical discovery in genetics history that was made using them.









6.   Give the name and one function of three different types of animal tissues.



7. Describe (don't just give a simple label!) four different isolating situations that can lead to the evolution of new species from the same starting group.



8. For the three basic layers of an early animal embryo, give -




Link to Answer Key


Answer as many or as few as you wish. You can't lose points on the rest of the exam by getting these wrong. Partial credit is possible.

What was the actual purpose of the salt in the diffusion lab salt solution? Three Points.

How are contractile vacuoles and central vacuoles filled? Three Points.

What is the counter-force to root pressure? Three Points.

Why would carriers follow Michaelis-Menten kinetics? Three Points.

What is the spindle “pull rule”? Three Points.

What bad thing might happen if the tail of a sperm cell wound up inside a fertilized egg cell? Four Points.

Why might a species have no process for counteracting polyspermy? Three Points.

What shape is a human blastula, and why? Four Points.

Why did Mendel do his genetics work on pea plants? Three Points

What process follows LaMarkian patterns? Three Points.



BI 171



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