A farmer uses triazine herbicide to control pigweed in his field.
For the first few years, the triazine works well and almost all the
pigweed dies; but after several years, the farmer sees more and
more pigweed. Which of these explanations best explains what
happened?
A. The herbicide company lost its triazine formula and started
selling poor-quality triazine.
B. Natural selection caused the pigweed to mutate, creating a
new triazine-resistant species.
C. Triazine-resistant pigweed has less-efficient photosynthesis
metabolism.
D. Triazine-resistant weeds were more likely to survive and
reproduce. Correct Answers D. Triazine-resistant weeds were
more likely to survive and reproduce.
A large seaweed that floats freely on the surface of deep bodies
of water would be expected to lack which of the following?
A. Thalli.
B. Bladders.
C. Holdfasts.
D. Gel-forming polysaccharides. Correct Answers C.
Holdfasts.
A population of organisms will not evolve if _____.
A. all individual variation is due only to environmental factors.
B. the environment is changing at a relatively slow rate.
,C. the population size is large.
D. the population lives in a habitat without competing species
present. Correct Answers A. all individual variation is due only
to environmental factors.
According to the concept of punctuated equilibrium, the
"sudden" appearance of a new species in the fossil record means
that _________.
A. the species is now extinct.
B. speciation occurred in one generation.
C. speciation occurred rapidly in geologic time.
D. the species will consequently have a relatively short
existence, compared with other species. Correct Answers C.
speciation occurred rapidly in geologic time.
After the drought of 1977, researchers hypothesized that on the
Galápagos island Daphne Major, medium ground finches with
large, deep beaks survived better than those with smaller beaks
because they could more easily crack and eat the tough Tribulus
cistoides fruits. A tourist company sets up reliable feeding
stations with a variety of bird seeds (different types and sizes) so
that tourists can get a better look at the finches. Which of these
events is now most likely to occur to finch beaks on this island?
A. Evolution of yet larger, deeper beaks over time, until all birds
have relatively large, deep beaks.
B. Evolution of smaller, pointier beaks over time, until all birds
have relatively small, pointy beaks.
C. Increased variation in beak size and shape over time.
, D. No change in beak size and shape over time. Correct
Answers C. Increased variation in beak size and shape over
time.
All protists are ______.
A. unicellular.
B. eukaryotic.
C. symbionts.
D. mixotrophic. Correct Answers B. eukaryotic.
An individual mixotroph loses its plastids, yet continues to
survive. Which of the following most likely accounts for its
continued survival?
A. It relies on photosystems that float freely in its cytosol.
B. It must have gained extra mitochondria when it lost its
plastids.
C. It engulfs organic material by phagocytosis or by absorption.
D. It has an endospore. Correct Answers C. It engulfs organic
material by phagocytosis or by absorption.
Arrange the following in order from largest to smallest,
assuming that they all come from the same fungus.
1. Basidiocarp
2. Basidium
3. Basidiospore
4. Mycelium
5. Gill
A. 4 → 5 → 1 → 2 → 3