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.

The first seventeen questions all deal with commercial fruit growing.

1. An organism called Taphrinia cerasi grows in the tissues of cherry trees. Taphrinia cerasi often weakens or even kills the trees it grows on. This is an example of

parasitism

2. Taphrinia causes the tips of growing stems to split up and grow into bunches of small, irregular branches called "witches' brooms." This means that Taphrinia must somehow affect the plants'

apical meristems

3. Taphrinia forms microscopic filaments of cells that grow in the cherry trees' tissues. The filaments are surrounded by cell walls made of the substance chitin. This means that Taphrinia must be a/an

fungus

4. The filaments of cells that make up Taphrinia are known as

hyphae

5. A plant scientist wants to make sure that witches' broom disease is really caused by Taphrinia cerasi. She first finds a large number of affected trees, and she successfully isolates T. cerasi from every one. What is the very next step she should take?

try to grow T. cerasi in culture
The question is really asking about Koch's postulates, though I didn't mention them by name. If she succeeds in growing the parasite in culture, she'll have fulfilled Koch's second postulate.

6. Cherry trees -- and most other fruit trees -- can also be attacked by a bacterium known as Agrobacterium tumefaciens, which causes swellings known as "crown gall." Since it is a bacterium, A. tumefaciens cells do not have

a chitinous exoskeleton

a nucleus
My error here: Both of these answers are right.

7. A. tumefaciens cells are bacilli-which means they look like

rods

8. A tumefaciens causes tumor-like growths to appear on the sides of stems and branches of an infected tree, usually at points where the tree has been wounded. This means that the bacterium must somehow be affecting the tree's

cambium
It can't be the cork, because cork is dead tissue and can't grow. The bacterium must be affecting cells that are still capable of active division.

9. Related bacteria to A. tumefaciens cause leaf canker disease when they enter a plant's leaves through specialized openings called

stomata

10. These openings in plant leaves allow transpiration to happen, which is

the loss of water from the leaves

11. The bacteria that cause leaf canker can also enter a plant's leaves through a scratch or wound in the outermost waxy layer that protects a leaf, the

cuticle

12. Finally, cherry trees can be attacked by wingless insects known as scale insects. Scale insects belong to the phylum

Arthropoda
Why? Because all insects belong to the Arthropoda.

13. Members of the phylum to which scale insects belong have all of the following features EXCEPT:

a notochord

14. Scale insects are known as r-selected organisms. This means that

they reproduce rapidly, producing large numbers of offspring
The reason that the answer's not "their population would grow exponentially if there were no limits" is because this is true of every species, r-selected or not.

15. Scale insects have long, hollow, tubelike mouths that they use to suck sap from plants. These mouthparts must therefore penetrate into the plant's

phloem

16. In one of the weirdest ecological relationships of all time, a fungus called Septobasidium can penetrate into a scale insect's body and start absorbing the sap that the insect is sucking from the plant that it's on. Insects with this fungus growing inside them are paralyzed, but they survive, they actually continue to reproduce, and they live longer than scale insects without the fungus. This is a case of

mutualism
True story, by the way. No way am I warped enough to make this stuff up.

17. The same fungus can grow together with certain algae, taking nutrients from the algae and protecting the algae "in return". The growth that the two produce is called a

lichen

18. PCBs (polychlorinated biphenyls) are a type of toxic chemicals used as pesticides, among other things. Recently, three scientists found that fur seals on Alaskan islands had unusually high concentrations of PCBs in their fat and milk. (See http://www.cifar. uaf.edu/ari00/loughlin.html) Why might seals, in particular, have high PCB levels in their bodies?

Seals are high-level consumers in the local food web.
Remember biological magnification?. . .

19. A student who was really reaching for an excuse to miss class might claim that he was stung by a member of the Phylum

Cnidaria
This is the only phylum, out of the five options you had, whose members all have the ability to sting (such as jellyfish).

20. Where would be a good place to find bryophytes?

Growing on moist patches of earth.

21. Why would you find bryophytes growing in the place in question #20?

Bryophytes have no vascular tissue.

22. If I tell you to point to a part of your body that is made mostly of epithelial tissue, you should

pick your nose
Because epithelial tissue lines the insides of cavities, including your nose.

23. Many Japanese and American warships were sunk during the Battle of the Coral Sea, fought in the Pacific Ocean during World War Two. Divers who visit these wrecks today, almost sixty years later, report that the sunken ships are covered with life-corals, worms, sponges, clams, snails, and many others. This is an example of

primary succession

24. If you mate a purebred white horse (specifically, a purebred cremello horse-there's more than one type of white horse) and a purebred chestnut brown horse, all of the offspring will have golden or golden-brown coats with light-gold manes (known as "golden palomino"). This is an example of

incomplete dominance

25. If you mate golden palomino horses with each other, then-assuming you get a large number of offspring-the offspring should have what coat colors?

half will be golden palomino, one-quarter will be brown, and one-quarter white

26. Which Kingdom is the first to appear in the fossil record?

Monera

27. A person with the disease tetanus is affected by bacterial exotoxins, which are

toxins that are released from bacterial cells

28. James Lovelock's idea that the entire Earth is a homeostatic system, like a single organism, is known as the

Gaia hypothesis

29. A rare disease called Ellis-van Creveld syndrome is caused by a single recessive gene (evc). Persons with Ellis-van Creveld syndrome show dwarfism, extra fingers and malformed hands, and heart defects. How can this be?

The evc gene can have multiple effects.

30. Which of the following is bilaterally symmetrical?

A 1957 Chevrolet.

31. I used to see a stray cat in my neighborhood who had seven toes on each foot, a condition known as polydactyly. The polydactylous allele is dominant to the normal allele. What can we know about the stray cat's parents?

at least one was polydactylous
Why? The stray cat I saw must have had at least one copy of the polydactyly allele (call it P). Thus at least one of his parents must have had at least one copy of P. In other words, at the very least, one parent had the Pp genotype. Since P is dominant, at least one of the stray's parents must have been polydactylous. (But both parents could have been polydactylous; we can't be sure.)

32. To raise enough beef to feed one person for two months takes about 1.5 tons of corn and soybeans. The same amount of corn and soybeans, used as a direct food source, could support over 20 people for the same amount of time. Why is this the case?

Most of the available food energy is lost at each trophic level.

Ellie Mae Johnson, the lounge singer at the Holiday Inn in Weatherford, Oklahoma, unexpectely gives birth to a baby boy. She ends up suing four different truck drivers for child support-not being very good at arithmetic, she's not sure which one's the father.

33. Miss Johnson has type A blood, and her baby has type O blood. Which of the four truckers could not be the father?

Skeeter, who has type AB blood
Remember that A and B are both dominant to O. The baby must have the OO genotype, meaning that he must have received one O gene from Mom and one O from Dad. Skeeter is the only individual whom we know has no O alleles to pass on to his kids. The truckers with A blood and B blood could have the AO and BO genotypes, and of course the trucker with type O blood must have the OO genotype.

34. What genotype must Miss Johnson have?

AO
Again, the baby must have received one O gene from Mom. If Miz Johnson has type A blood, she must have the AO genotype.

35. Ellie Mae has brown eyes, and so do all four truckers, but her baby has blue eyes. The simplest explanation is that

brown eye color is dominant to blue

36. Billy Bob finally 'fesses up that he's most probably the father. If he's right, what must his genotype be?

BO
Same logic as question 34.

37. Billy Bob does the honorable thing: he moves to Weatherford, Oklahoma, courts and marries Ellie May, and works hard drivin' his rig to support his kid. This shows that
he is a member of a K-selected species

38. Which of these processes does not directly drive or affect the nitrogen cycle?

weathering of rocks

39. The process listed above in question #38 that does not drive the nitrogen cycle is involved in the

phosphorus cycle

40. Which of the following features is shared by all chordates, and only chordates, at some stage in their life cycle?

pharyngeal slits
Coeloms and bilateral symmetry are shared by many more phyla than just the Chordata.

41. Animal cells are surrounded by a/an ________ made up largely of __________.

extracellular matrix; collagen

42. Starfish and sand dollars are members of which phylum?

Echinodermata

43. Prairie dogs are burrowing rodents that used to be extremely common on the prairies and grasslands of America. Prairie dogs eat seeds and plants, and in turn they are food for hawks, eagles, ferrets, foxes, falcons, badgers, and coyotes. This makes prairie dogs

primary consumers

44. Burrowing owls, which as their name suggests live in burrows in the ground, often use abandoned prairie dog holes as homes. Since burrowing owls are too small to eat prairie dogs, the relationship between the two species is

commensalism

45. Another effect that prairie dogs have is this: Their burrows cause rain water to soak into the soil, instead of running off the land and causing floods; this in turn allows more plants to grow. Plants transport water through their bodies using a tissue known as xylem, which is

dead when mature and functional

46. Prairie dogs are considered a keystone species in the prairie ecosystem. This means that:

removing prairie dogs causes drastic changes all through the ecosystem

47. In the wild, the American bald cypress tree, Taxodium distichum, grows best in very moist or even waterlogged soils (such as in swamps). It doesn't tolerate shade or harsh winters well, and so is not usually found north of the state of Delaware. These factors describe its

niche

48. A fur rancher crosses two mink (weasel-like animals raised for their expensive fur) that both have a light fur color known as "blue frost." This pair of mink produces several litters of offspring, and the rancher finds that, out of 78 offspring of this pair, 52 have blue frost fur and 26 have normal brown fur. If we were to let W⁰ represent the gene for brown fur, and W^F be the gene for blue frost fur, what would the genotypes of the parents be?

both would be W^F W⁰
All other options you were given would imply either that the parental mink weren't both "blue frost" (say, if both were W⁰ W⁰), or that there shouldn't be a mixture of brown and blue frost mink in the offspring (say, if both were W^F W^F).

49. Assuming that the numbers accurately reflect the genetics of the cross described in question #48, what is the likeliest explanation for them?

The genotype W^F W^F is lethal in early development
Because 2/3 of the offspring are blue frost and 1/3 are brown. Same problem as Manx cats.

50. The current Governor of the state of Arkansas is

Mike Huckabee