Fall 1999

Lecture Exam 1 -- KEY
[NOTE: On this key, any explanations I have added to the correct answers are in brackets.]

This exam consists of 50 multiple-choice questions. Each one has only one right answer. Read each question and all possible answers carefully before answering.

Please mark your answers on the Scantron form provided, using only #2 lead pencil. If you erase an answer, make sure you erase it fully, or the machine may mark it incorrect. Check carefully to ensure that your answers are on the correct rows on the Scantron form.

Turn in both the Scantron form and the test paper when you are finished. Make sure your name is on both. You may write on the test paper if you wish, but anything you write on the test paper will not be graded.

Good luck.

For the first ten questions, evaluate the statements given as to their scientific validity.

[GENERAL NOTE: Science does not prove anything. That answer was never the correct one. Nor are all "scientific statements" true; many are later shown to be false, as in #2.]

1. "The speed of light is, like, sort of fast."
Unscientific statement because it's too vague

2. "The Earth is flat and fixed in the center of the universe, and the sun, moon, planets, and stars all revolve around it."
Scientific statement because it's testable [It's probably not true. . . but you can test it by, for instance, sailing around the world to see whether you fall off the edge. . .]

3. "Jaci Velazquez's latest album is much cooler than anything Rebecca St. James has ever recorded, but they're both damp-dishrag dorkettes compared to Alanis Morrisette."
Unscientific statement because it contains an aesthetic judgment

4. "The god Brahma creates the universe, Shiva destroys it, and Vishnu incarnates himself within it in order to preserve and sustain it."
Unscientific statement because it relies on the supernatural

5. "Americans should be allowed to carry as many handguns as they choose."
Unscientific statement because it contains a moral or ethical judgment

6. "Plants make sugars from carbon dioxide, water, and solar energy."
Scientific statement because it's testable

7. "Elvis Presley is alive in an alien base on the Moon, and is beaming continuous video transmissions of Viva Las Vegas right into Win Thompson's cable TV hookup."
Scientific statement because it's testable

8. "Elvis Presley is alive in an alien base on the Moon, but the aliens have a magical invisibility cloaking device which means that Earthlings can never detect him."
Unscientific statement because it can't be tested

9. "The battle of Pea Ridge was fought in March of 1862 near Elkhorn Tavern, Arkansas."
Scientific statement because it's testable [How could you test it? By going there and digging for old bullets, buttons, cannonballs, etc. Or by going to the archives and looking up old newspapers, letters, journals, etc.]

10. "People are descended from monkeys."
Scientific statement because it's testable [Believe it or not, this statement is, technically, not true. But how could you test it? By digging up fossils and looking for "missing links", for example.]

11. The shell of a peanut comes from what part of the flower?
Ovary wall

12. Which of these organisms does not show alternation of generations?

13. Which of these organisms does not have cell walls?

The small wormlike organism shown here belongs to the phylum Kinorhyncha, which you've never seen before. On the left is a drawing of the whole organism. On the right is a cross-section through its body.

14. This organism's Latin name is Pycnophyes frequens. What is the name of its genus?

15. A similar-looking organism goes by the name of Trachydemus dujardinii. These two organisms are in the same class. Therefore, they must also be in the same

16. This organism is segmented. Which other animal phyla are also segmented?
A and B [Annelida and Arthropoda]

17. Why doesn't Pycnophyes frequens belong to the Platyhelminthes?
It has a coelom. [Empty space surrounding the gut is visible in cross-section]

18. The actual size of Pycnophyes frequens is about 700 microns. This is equivalent to
0.7 millimeters [Yes, this did require you to know a little bit about the metric system, and to be able to multiply by powers of 10. . .]

19. Why doesn't Pycnophyes frequens belong to the Arthropoda?
It doesn't have jointed legs.

20. Pycnophyes feeds on single-celled algae. This makes it a / an

21. Imagine that you are the bacteriologist F. J. S. Löffler, a star pupil of Robert Koch, working in the 1870s. You've taken blood samples from several children who are dying of the disease diphtheria, and you've found a bacterium in each one, which you name Corynebacterium diphtheriae. You've managed to isolate and grow C. diphtheriae in a nutrient broth. Based on what your teacher probably taught you: what should you do next to test the hypothesis that C. diphtheriae causes tetanus?
You should inject the cultured C. diphtheriae into healthy people (or more practically, into healthy mice or rats). [This is the third of Koch's Postulates, right?]

22. Now imagine that you are the bacteriologist Emil Behring, who developed a drug to treat diphtheria (called diphtheria antitoxin) around the year 1890. You test it by injecting it into a group of infected mice, and they all recover. Why is this a poor experiment?
You didn't use a control group. [Maybe the mice would have recovered anyway.]

23. Behring's diphtheria antitoxin works by counteracting a toxic substance that C. diphtheriae cells release to float freely. This is an

24. A typical cell from a plant leaf will contain
mitochondria and chloroplasts

25. Porcupines often feed on tree bark, stripping it completely off with their teeth. This hurts the tree because
it interferes with the flow of sugars through the phloem.

26. The immature, dividing cells at the tip of a plant stem make up the

27. The Cnidaria and the Echinodermata used to be classified together. What is one feature that members of both phyla have in common?
radial symmetry

28. Which of the following chemical elements is not one of the ones that are basic to all life and that make up most living tissue?

29. What are two features found in the Echinodermata that are not found in the Cnidaria?
coelom and skeleton of interlocking plates

30. In an animal, a grouping of cells of the same type and function in a connected group (often a flat sheet of cells) is a / an

31. Certain bacteria can be found living
all of the above [i.e. in boiling-hot water, plant roots, human skin, and strong acid]

32. The antibiotic chloramphenicol kills bacteria, but has the unfortunate side effect of killing off mitochondria. This means that organisms dosed with chloramphenicol
cannot generate energy from food

33. A marine flatworm called Convoluta roscoffensis has single-celled algae living under its skin. It provides shelter to the algae, and in turn takes up nutrients that the algae produce by photosynthesis. This is an example of

34. Clavaria vermicularis, the "fairy fingers" fungus, produces sexual spores on the ends of microscopic club-shaped structures. This makes it a /an
basidiomycete [Don't believe there is such a thing as a "fairy fingers" fungus? See for yourself. . .]

35. How many nuclei would be present in each cell making up a "fairy fingers" fruiting body?
two [It's dikaryotic, remember?]

36. In biological classification, a family may be divided into several

37. About how many species of animals, plants, etc. are known to live on Earth?

38. The organism you see here is called Volvox aureus (actual size about 1 mm). It is photosynthetic, eukaryotic, and multicellular, but it's not considered a plant. Why not?
It has no cellular differentiation.

39. If Volvox aureus isn't a plant, what is it?
a protist

40. Volvox aureus has a two-part name. The convention of giving organisms two-part names is known as
binomial nomenclature

41. Which of these is not a type of complex molecule that's essential for life?

42. Internal compartments and structures inside a cell that carry out specific functions are called

43. An organism is said to be saprotrophic, or saprobic, if it:
feeds on dead organic material and causes decay

44. Plants lose water through their leaves, a process called

45. Plants lose water through their leaves, and also take up carbon dioxide, through holes in the underside of each leaf called

46. The bacterium Treponema pallidum is shaped like a long corkscrew. Because of its shape, it's called a

47. Which characteristic is not found in all members of the Chordata at some point in their lives?

48. A typical bryophyte would be
a moss.

49. The common name for the male gametophyte of a conifer or flowering plant is:

50. The capital and largest city of Arkansas is
Little Rock [Now the challenge: Where are Ulan Bator, Khazad-dum, Ouangadougou, and Minas Morgul are, and what are they the capitals of? Hint: Two of them don't exist in our world. . .]

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