In: Biology
1. True or False? Plants take up nitrogen from the atmosphere in the same way that they take up atmospheric carbon.
2. Large animal aggregations such as bird colonies, herds of large herbivores, and shoals of fish provide "safety in numbers" from predators. As a result, individuals in larger groups have higher survival & greater rates of reproduction than individuals in smaller groups. This represents an example of which of the following?
A. Positive density dependence
B. Negative density dependence
C. Density independent population regulation
D. None of the above
3. Legumes contain nitrogen-fixing bacteria in their roots that increase soil nitrogen for use by other species. This is an example of:
A. inhibition
B. tolerance
C. facilitation
D. suppression
Question 1
Answer: The statement " Plants take up nitrogen from the atmosphere in the same way that they take up atmospheric carbon " is False. This because plant take up nitrogen from soil but not from atmosphere.
Question 2
Answer: Positive density dependence is a type of density dependent population regulation in which population growth is regulated increased density of the population. This because female individuals will have high chance of mating with male in large population compare to small populations. Hence, large animal aggregations such as bird colonies, herds of large herbivores, and shoals of fish are the examples of positive density dependence. Hence, option A is the correct answer. In negative density dependence, population growth is reduced by large population, predation and competition. In density independent population regulation, population growth is regulated by climate and weather and is independent of population size. Hence, options B, C and D are incorrect.
Question 3
Answer: Legumes roots contain nitrogen-fixing bacteria that fixes atmospheric nitrogen and also increases the fertility of the soil there by facilitating the growth of other species. This is an example of facilitation. Hence, option C is the correct answer. Inhibition, tolerance and suppression will not benefit other species by improving soil fertility. Hence, option A, B and D are incorrect