Question 2 Which interaction between organisms would be described as parasitic? A. a mosquito feeding on the blood of a dog B. a bee gathering nectar and pollen from a flower C. a cleaner shrimp picking dead skin off a large fish D. a nonpoisonous snake mimicking a poisonous snake
A. a mosquito feeding on the blood of a dog The mosquito feeding on the blood of a dog is a parasitic interaction. A parasitic interaction is a relationship in which one organism is helped by the interaction while the other organism is hurt by it. The mosquito is helped by the blood it gets and the dog is hurt by the mosquito that is biting it.
Question 14 A park is home to a large number of robins, squirrels and rabbits. The robins and squirrels live in the park s trees. The robins feed on earthworms and insects that live on the ground. The squirrels eat the acorns produced by the park s oak trees. The rabbits hide in the bushes and feed on the grass. Which factor would directly limit the number of rabbits that could live in this park? A. number of robins B. number of bushes C. number of acorns D. number of squirrels
B. number of bushes The number of bushes will limit the number of rabbits that can live in the park ecosystem (environment). Bushes are an important part of rabbit habitat. They provide shelter for rabbits. If the number of bushes is limited, fewer rabbits will be able to live in the ecosystem
Question 23 In which environment is white fur color an advantage for survival? A. desert B. grassland C. arctic tundra D. temperate forest
C. arctic tundra An animal with white fur would be more difficult to see against the snow and ice in an arctic tundra. The white fur would make it harder for predators to find a white animal in a white place. So, having white fur is an advantage in an arctic tundra.
Question 28 Paramecia usually reproduce asexually. Fish reproduce sexually. Suppose the environmental conditions in the lagoon change. What advantage will the fish population have over the paramecium population? A. Sexual reproduction produces offspring that are identical to the parents. B. Sexual reproduction decreases the genetic variability in the fish populations. C. Sexual reproduction limits the spread of harmful characteristics in fish populations. D. Sexual reproduction allows populations to adapt to new conditions over fewer generations.
D. Sexual reproduction allows populations to adapt to new conditions over fewer generations. Sexual reproduction makes variety/ changes in a population more common. There will be more and more variation through sexual reproduction, because new combinations of good changes can show up in organisms by exchanging genes with a partner and recombining those genes.
Earthworms and birds have strong muscular gizzards. The gizzard grinds food into small bits before it passes on to the intestine. Mammals, in contrast, do not have gizzards. Why do earthworms and birds need to have gizzards but mammals do not? A. Earthworms and birds are not equipped to chew food. B. Earthworms and birds eat food that is difficult to digest. C. Earthworms and birds have intestines that work inefficiently. D. Earthworms and birds do not have stomachs to mix moistened food.
A. Earthworms and birds are not equipped to chew food. Birds and worms do not have teeth to chew food. So, the crop stores food and the gizzard grinds up food before it is passed on to the intestine.
Male mussels release sperm into the water. Female mussels take the sperm into their gill chambers where fertilization occurs. Young mussel larvae are released into the water where they float freely until they attach to the gill of a host fish. After a few weeks, they reach the juvenile stage and drop off. After the juvenile drops off the fish gill, it burrows into the river bed and begins the life cycle all over again. The parasitic behavior of the larvae benefits the mussel in two ways. One benefit is that the fish provides nutrition for the larvae when they are attached to its gill. What is the second way this behavior enhances the survival of the mussel species? A. The large size of the fish provides the mussel larvae with plenty of room to grow. B. The parasitism increases the opportunity for the mussels to mate with other mussel species. C. The mobility of the fish spreads the mussels to areas they would otherwise be unable to reach. D. The location of the larvae on the gills of fish reduces the exposure of the larvae to oxygen-rich water.
C. The mobility of the fish spreads the mussels to areas they would otherwise be unable to reach. The larvae of mussels attach to the gills of fish, so they travel with the fish and then drop off in places where the adult mussels could not go by themselves. This lets the mussels live and reproduce in new areas, so there is less competition between mussels from the same species.