SCI 135 - Third Exam Fall 2018


On the line to the left, place the letter of the choice that best answers the question.
Three Points Each. NOTE: "e" answers are never the correct answer.

        1. The nuclear envelope is called an envelope rather than a membrane because

_______    a. It can be sealed by folding over                             b. It has 2 membrane layers
                c. Only the outside of a cell is called a membrane        d. It sends communications to the rest of the cell
                                    e. That gives one more thing poor students need to learn

        2. Which are often used for crawling?

_______    a. Pseudopods         b. Microvilli         c. Microtubules        d. Lobosia
                                        e. Hands & knees on a bad night

        3. Sex cells like sperm and egg cells are -

_______    a. Diploid         b. Haploid         c. Triploid        d. Polyploid
                            e. I’m thinking something with a “ploid”

        4. In the lab, our plant cells shrank in the heavy salt solution due to

_______    a. Osmosis into the cells         b. Attraction to salt        c. Osmosis out of the cells
                d. Diffusion of salt                        e. They were very well trained ahead of time

            5. Much of a cell’s RNA is stored in

_______    a. Chromosomes         b. Ribosomes        c. Endoplasmic reticulum         d. Nucleoli
                                            e. In little plastic tubs with snap lids

        6. Genetic redundancy has to do with

_______   a. Extra chromosomes                    b. Proofreading during DNA replication
                c. How the codon codes work        d. Two sets of chromosomes
                    e. Looking like words but not really being words

        7. Cell walls would not be found in

_______    a. Animals         b. Plants         c. Bacteria        d. Fungi         e. The friendlier cell neighborhoods

        8. There is a much higher concentration of iodine inside thyroid cells than in the
                            fluid around them. Iodine moves into the cells by

_______    a. Cilia         b. Active transport         c. Osmosis        d. Passive transport         e. Skateboard

        9. Which point mutation is least likely to produce major changes?

_______    a. Substitution         b. Deletion         c. Addition         d. These are all equally bad
                                                    e. The less pointy one

        10. Which could be described as canals with production facilities?

_______    a. Nucleus         b. Smooth endoplasmic reticulum        c. Chromosomes
                d. Rough endoplasmic reticulum        e. Why not just call them that?

        11. A karyotype involves

_______    a. Comparing cell shapes        b. Counting cell divisions        c. Comparing chromosome shapes
                d. Counting organelles                                e. Folks that look like Kary

        12. DNA plus histones are called

_______    a. Nucleoli         b. Messenger DNA        c. Ribosomes         d. Chromatin
                                                e. Something very sciencey, I bet


Answer any eight of the following questions for 4 Points Each.
Note: if you answer more than eight, only the first eight will be corrected.
You can get partial credit on these answers.

1. What is one function of centromeres?

2. Two features HIV escape mutants have that makes them dangerous -


3. What is apoptosis?

4. Draw the layer layout of a typical cell membrane, with labels for the hydrophobic and hydrophilic layers.

5. For a low chromosome number (compared to a high one):


6. Define: what is diffusion?

7. The two different research areas very interested in telomerase -


8. What two organelles probably started as endosymbionts?


9. Give two different ways that fresh-water organisms deal with their potential osmosis problem.


10. What are two different types of molecules that act to arrange or rearrange the shape of protein molecules?


11. What does genetic linkage mean?

12. If a cell has lots of golgi bodies, what particular function is it probably performing?

13. Cells with lots of microvilli are generally doing one or both of which two particular basic functions?


14. What is the purpose of a polar body?

15. What are two different structures that make up cytoskeleton?


16. Briefly explain why most genetic diseases are recessive.  (It has to do with why any allele would be recessive)


Answer any four of the following questions for Eight Points Each.
Note: if you answer more than four, only the first four will be corrected.
You can get partial credit on these answers.

1. For four different types of vesicles or vacuoles, give the name and function:




2. Give three sets of differences between -




3. What are four different types of proteins that can be embedded in a cell membrane?


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




5. Using this DNA code give the messenger RNA sequence and, using the chart available with the exam, give the coded amino acid sequence.
Strand     T A C A G T C T A C T A G G C C T G T T G A G G A C T

mRNA ___________________________________________________________________________________


6. Give three sets of differences between -




7. Add the proper labels to any four indicated structures in this sketch of a cell.

Can't reproduce sketch here, sorry.

Link to Answer Key


Answer as many as you are able. Wrong answers will not result in points being lost from the main exam. You can get partial credit on these answers.

What is the major weakness of the “mathy” explanation for maximum size limits of cells? Three Points.

You’ll get more “pruney” swimming in a local lake than you will swimming in the ocean. Why is that? Three Points.

What was the really convincing evidence for the endosymbiont theory? Three Points.

Why exactly is an extra chromosome passed to an embryo very dangerous? Three Points.

Why do chromosomes have telomeres? Three Points.

What sorts of signals can “go bad” and produce cancer cells? Three Points each.

The simplest DNA proofreaders are set up to detect what about DNA while it is replicated? Three Points.

What is odd about the pieces when mRNA gets spliced? Three Points.


SCI 135 

Michael McDarby