Correct Answer: Option 3 environmental change

The species is not able to adapt to environmental change therefore this causes risk in their numbers. For instance, the white lemuroid possum, only found in the mountain forests of northern Queensland, has been named as the first mammal species to be driven extinct by global warming. The White Possum has not been seen in over three years. These possums cannot survive extended temperatures over 30 degrees C, which occurred in 2005.

Cloning, gene manipulation and genetic recombination are known processes used to ease extinction. If these are successful, the species will not be in danger of extinction.

Correct Answer: Option 3 natural selection

These species exhibit geographical variation, differences in genetic structure between populations. Because, at least some environmental factors are likely to be different from one place to another, natural selection can contribute to geographical variation.

Different species exhibit different characters so there is very little probability that resistance to diseases brought about the structural differences. Thus, options 1 and 2 are incorrect.

Selective breeding can cause variation in the species structure; however, it is not the best answer because of its low probability.

Correct Answer: option 1 survival of the fittest

It can be observed that the dark-colored insects were few while the light-colored insects were many before the first spray of pesticide. After three sprays, the dark-colored increased in numbers, while the light colored decreased significantly. This shows that the dark-colored are resistant to the pesticide, thus, survived better than the light-colored ones.

Dynamic equilibrium (the populations are not in steady state), succession (ecological changes did not involve the whole community) and extinction (both species still exist) were not illustrated in this experiment, thus, the other options are incorrect.

The Cactus finch will least likely compete with Warbler finch and Woodpecker finch. Based on the diagram, Cactus finch prefers to eat mainly plant food, while Woodpecker finch prefers mainly animal food. They will just compete whenever either of their major food preference is scarce. Warbler finch prefers to eat animal food only, thus, it will compete with Woodpecker finch. Warbler finch will rarely compete with Cactus finch because Cactus finch prefers plant food than animal food.

Correct Answer: Option 2 birds acquired larger beaks due to dded exercise of feeding on large seeds.

Due to the scarcity of small seeds, the birds have adapted by the gradual increase in the size of beaks.

Option 4 is incorrect because the birds were not exposed to agents of mutation such as ultraviolet or ionizing radiation, chemical mutagens, or viruses.

The reproduction success of the birds with large beaks was not mentioned in the given information. Thus, option 1 is invalid.

The number of medium-beaked birds was not yet decreasing so there is very low probability of interbreeding with the birds with large beaks. Hence, option 3 in invalid.

Correct Answer: Option 4 There is increased competition for a limited number of small seeds

Whenever food is scarce, and there is a high demand for food, the competition for accumulating that food will increase in order for the population to survive.

Option 1 is incorrect because the primary goal of the birds is to survive.

Option 2 is incorrect. The birds with large beaks will not have a change in food preference because their nutrition source is not at risk. Only small seeds are scarce during dry season. They can still eat the large seeds because of the size of their beaks.

Not all finches will be affected by the dry season and parasitism is not a characteristic of finches. Thus, option 3 is incorrect.