The reproductive success of an organism depends in part on the ability of the organism to survive. How does the physical appearance of these organisms help them survive? A. Their physical appearance helps them find a habitat. B. Their physical appearance helps them resist parasites. C. Their physical appearance helps them avoid predators. D. Their physical appearance helps them defend a territory.
C. Their physical appearance helps them avoid predators. The organism s camouflaged appearance allows it to blend in with the surrounding environment and hide from predators.
Question 13 Termites eat wood but cannot digest it. Protozoans live in the termites stomachs and use enzymes to break down the wood. The digested wood provides nutrition for both the termites and the protozoans. What type of relationship is this? A. mutualism B. parasitism C. predation D. commensalism
A. mutualism Mutualism occurs when both organisms benefit from each other. The protozoan benefits by having a safe and appropriate habitat. The termite benefits by having access to the digestion products of the protozoan.
Question 35 Highways allow people to travel between towns and cities. These highways also divide ecosystems into smaller pieces. Animals can become separated from lakes they use for breeding. For example, tiger salamanders travel long distances to breed at lakes. How could highway systems affect animals such as the tiger salamander? A. Tiger salamander habitats may be exposed to less pollution. B. Tiger salamanders may be cut off from important resources. C. Tiger salamanders could improve their ability to remember roads. D. Tiger salamander habitats within ecosystems could become larger.
B. Tiger salamanders may be cut off from important resources. Highways could isolate salamanders from their habitats, breeding sites and food sources. April 18, 2012
Which organism gets food energy directly from both plants and animals? A. fox B. grass C. grasshopper D. snake April 18, 2012
A. fox The diagram shows arrows pointing to the fox from the berries, mouse, grasshopper, and snake. This means that the fox gets energy directly from eating both plants and animals. April 18, 2012
Question 2 Planaria are flatworms that are found in shallow streams, often attached to the bottoms of rocks. A class is studying a population of planaria in a nearby shallow stream. The graph below shows data collected over 11 weeks. The population started to decrease after 5 weeks. The students concluded that the stream did not have enough food to support a large population of planaria. If this trend continues, how many planaria will be living in the stream by the 12th week? A. 600 B. 500 C. 400 D. 300
C. 400 The data in the graph show that the planaria population is decreasing by 200 individuals per week. If this trend continues, the population will decrease by 200 from week 11 to week 12. Since the population size is 600 in week 11, a decrease of 200 will bring the population size to 400. April 18, 2012
The illustration below shows how a strawberry plant reproduces by asexual reproduction to form a new plant. Describe one advantage that asexual reproduction might offer the strawberry plant. (2 points)
What is Expected The new plant will have all of the same genes as the parent plant (it will be genetically identical). One advantage of asexual reproduction is that the offspring have the same genes as the parent plant. If the parent plant is well adapted to its environment then, because they have the same genes, the offspring will also be able to live in the environment. April 18, 2012
Question 8 Bass tapeworms attach to the gills and intestines of bass fish. These worms survive by taking nutrients from the bass. What type of relationship does this represent? A. predation B. parasitism C. mutualism D. commensalism
B. Parasitsm April 18, 2012
Question 16 In 2002, the club reported to the North American Butterfly Association that the Striped Hairstreak butterfly was extinct. In their report, the students wrote that they suspected that the local pesticide spraying in 2000 was the cause of the extinction of this butterfly species. The students received a reply stating that their conclusion was not scientifically valid. In your Answer Document, give two reasons why their conclusion was not scientifically valid. (2 points)
What is Expected The students conclusion that this species of butterfly was extinct is not scientifically valid because the data the students collected was for only one town in Ohio. For a species to be extinct, there must be no living members of the species anywhere in the world. Another reason the conclusion is not scientifically valid is that there have only been 2 years with no sightings of this butterfly species. Another reason the conclusion is not scientifically valid is that there is no evidence that the spraying of the pesticide was the cause of the butterfly disappearance. April 18, 2012
Question 17 In the summer of 2000, a large number of Gypsy moths were seen on the trees. To protect the trees from the Gypsy moths, the town government sprayed a pesticide that kills only insect larvae. Which correctly explains the probable relationship between the spraying of pesticide and the number of butterflies observed in 2001? A. There were more butterflies because there was less competition for food from the Gypsy moths. B. There were fewer butterflies because the butterflies left the area to get away from the pesticide. C. There were more butterflies because the butterflies ate the Gypsy moth larvae killed by the pesticide. D. There were fewer butterflies because the pesticides killed the larvae of both the Gypsy moths and the butterflies.
D. There were fewer butterflies because the pesticides killed the larvae of both the Gypsy moths and the butterflies. The pesticide that kills insect larvae would also kill the butterfly larvae, since butterflies also have a larval stage in their life cycle. April 18, 2012
Question 29 Aphids are small insects that sometimes live near ants. The ants protect the aphids from predators. The aphids produce a sweet substance that the ants eat. Which statement describes the relationship between ants and aphids? A. Both ants and aphids benefit. B. Both ants and aphids are unaffected. C. The ants benefit and the aphids are harmed. D. The aphids benefit and the ants are unaffected.
A. Both ants and aphids benefit. In this relationship, both organisms benefit because the ants protect the aphids and the aphids provide food for the ants. April 18, 2012
Sea otters are marine mammals that live in giant kelp forests along the Pacific coast of North America. Sea otters have an important role in the food web of this ecosystem. When sea otters are removed from the giant kelp forest, the kelp also begins to disappear. In your Answer Document, explain why the absence of sea otters would lead to a decrease in the giant kelp. Then, choose another organism in the food web and explain why the decreasing amount of giant kelp would affect that organism. (2 points)
What is Expected The absence of sea otters would lead to a decrease in the giant kelp population because there would be an increase in the number of sea urchins, which eat the giant kelp. A decrease in the giant kelp population could cause a decrease in the number of snails, because the snails would have less food. April 18, 2012
Question 4 Aphids are a common plant-pest insect. They alternate between asexual and sexual reproduction. During the summer, aphid populations grow quickly by asexual reproduction. As winter approaches, aphids switch to sexual reproduction. What advantage does the switch to sexual reproduction give the aphids? A. Sexual reproduction maintains a constant level of variation in the population and requires less energy. B. Sexual reproduction decreases variation in the population and prevents the spread of harmful mutations. C. Sexual reproduction increases variation in the population and provides for adaptability in a changing environment. D. Sexual reproduction produces individuals that are clones and allows rapid population growth under stable environmental conditions.
C. Sexual reproduction increases variation in the population and provides for adaptability in a changing environment. Sexual reproduction results in offspring with new genetic combinations. This can lead to an increase in genetic variation within a population. Genetic variation may allow the species to survive in a changing environment. April 18, 2012
Question 6 Aphids, ants and plants interact with one another through symbiotic relationships. Aphids are small insects that poke holes in plants and suck out sap. Aphids may cause the plant s leaves to wilt and curl. Ants protect aphids and eat the sugary liquid that aphids produce. In your Answer Document, choose two of the organisms in this symbiosis. Describe the relationship between the two organisms in terms of the benefit or harm to each organism. (2 points)
What is Expected There are different types of symbiotic relationships between organisms. In this case, the aphids benefit from consuming the plant, but the plant is harmed in the process. The ant and the aphid, however, benefit from each other and neither is harmed in the process. The aphid receives protection from the ants while the ants are provided with food from the aphids. April 18, 2012
Question 39 The shape of an animal s body is related to where it lives and how it feeds. Which fish has a body shape that is best suited for feeding at the bottom of a lake?
The underside of this fish is flat, which allows it to swim close enough to the lake bottom to find food. Also, the shape of the mouth is turned down, which indicates that this fish is adapted to feeding from beneath its body. April 18, 2012