SC 135 - Third Exam Fall 2009

MULTIPLE CHOICE.

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.  A karyotype involves

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

                     ...it's the comparison of overall numbers and shapes that's unique to each species.

                2.  Genetic redundancy applies to

___A___ a. Crossing over and substitution mutations            b. Enzyme amplification and meiosis II            c. Allele amplification and meiosis I
              d. Prokaryotes only                                                                            e. What terms I've totally forgotten

                     ...redundancy from extra gene copies in the first, redundancy from mutations giving the same amino acids in the second.

                3.  In mosaicism, cells have different

___D___ a. Parents             b. Numbers of nuclei            c. Types of projections             d. Numbers of chromosomes            e. Religions

                     ...they weren't distributed properly during a cell division, putting one too many in one (and its descendants), one too few
                       in the other.

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

___C___ 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

                     ...shrinking implies loss, and water diffused (osmosis) from where there was more (inside) to where there was less (the heavily
                        salty solution outside).

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

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

                     ...it's one of the basic functions.

                6.  Which vesicle would have digestive enzymes in it?

___A___ a. Lysosome             b. Ribosome            c. Digestisome             d. Nucleosome            e. Tum-tum-osome

                     ...again, the basic function.

                7.   A zygote is ________ and divides by ________

___C___ a. Haploid...meiosis             b. Haploid...mitosis            c. Diploid...meiosis             d. Diploid...mitosis            e. A weird goat...splitting

                     ...2 sets of chromosomes, and makes copies of itself.

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

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

                     ...if it moved passively by diffusion, it would go the other way.

                9.   Position effects influence how

___B___ a. Quickly cells divide             b. Easily genes get expressed            c. Organelles work together             d. All of these
                                                                e. Well, if you want to make boy babies...

                     ...some chromosome positions are more densely bundled, making genes there harder to get at and use.

                10.  The chromosome number of prokaryotes is

___C___ a. Always divisible by two             b. Always divisible by three            c. One             d. Not reliable            e. Always higher than they want to admit

                     ...they just have the one, loop-shaped chromosome.

                11. Radiation is most likely to damage cells that are

___D___ a. Small                 b. Big                 c. Old                d. Dividing                 e. Just being wusses

                     ...that's when DNA breaks, bad repairs, and loose pieces become important.

                12.  Crossing over typically happens during

___B___ a. Interphase             b. Meiosis I             c. Meiosis II            d. Mitosis             e. The middle of a moonless night

                     ...that's when homologous chromosomes are pulled in next to each other.

SHORT ANSWER.

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.

LONG ANSWER.

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.

BONUS QUESTIONS.

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.

The ability to produce a particular structure turns a cancer malignant. What structure? Three Points.

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

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

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

Why does a progressing cancer pretty much have to reactivate its telomerase gene expression? Three Points.

What determines whether an alligator is male or female? Three Points.

DNA proofreading works best in organisms that fill in below . Three Points.

GENE TRANSLATION TABLE

CODONS ON MESSENGER RNA