Topic 8 - Keystone Sample Quiz

The diagram shows the branching pattern of evolutionary relationships between different groups of organisms. It suggests that earthworms and sea stars share a common ancestor, as they both branch off from the same point on the diagram. This conclusion can be drawn based on the principle of common ancestry, which states that organisms that share a common ancestor will have similarities in their genetic makeup and physical characteristics.

Evolution can occur most rapidly in bacteria because they have short generation times and high mutation rates. Bacteria reproduce quickly, allowing for more opportunities for genetic variation to arise. Additionally, their high mutation rates increase the likelihood of beneficial mutations that can lead to evolutionary changes. In contrast, humans, fish, and birds have longer generation times and lower mutation rates, making the pace of evolution slower in these organisms.

The diagram shows that species B and C are present in the current environments. This suggests that these two species have successfully evolved and adapted to the present conditions, allowing them to survive and be found in today's environments.

Extinction of a species is most likely to occur as a result of environmental changes. Environmental changes can include factors such as habitat loss, climate change, pollution, and natural disasters. These changes can disrupt the delicate balance of ecosystems and negatively impact the survival and reproduction of species. As a result, species may not be able to adapt quickly enough to the new conditions, leading to their extinction. Migration, evolution, and selective breeding may play a role in the survival and adaptation of species, but they are not the primary drivers of extinction.

The statement "New varieties of plant species appear more frequently in regions undergoing climatic change" suggests that evolution is still occurring at the present time. This is because the appearance of new varieties indicates that genetic changes are happening within plant populations, allowing them to adapt to changing environmental conditions. This is a key aspect of evolution, as it involves the accumulation of genetic changes over time that lead to the development of new species or variations within existing species.

The correct answer is natural selection. The diagram shows the heads of four different species of Galapagos Islands finches, each with a different type of beak. This suggests that the beak morphology has evolved over time in response to different ecological niches and food sources available on the islands. Natural selection is the mechanism by which individuals with traits that are advantageous for their environment are more likely to survive and reproduce, passing on those traits to future generations. Therefore, it is likely that the different beak types in the finches have been selected for through natural selection.

Bacteria have higher rates of reproduction compared to mammals, allowing them to evolve more quickly. This is because bacteria can reproduce rapidly, with some species having a generation time as short as 20 minutes. This means that they can produce a large number of offspring in a short period of time, increasing the chances of beneficial mutations occurring and spreading through the population. In contrast, mammals have longer generation times and produce fewer offspring, resulting in slower rates of evolution.

The differences observed in bird beaks are most likely due to the selection for different shaped beaks that best suit different niches. This means that over time, birds with beaks that are better adapted to their specific environment and feeding habits are more likely to survive and reproduce, passing on their genes for beak shape to future generations. This process is known as natural selection and is a key mechanism of evolution. Asexual reproduction, genetic recombination associated with mitotic cell division, and genetic engineering are not likely explanations for the observed differences in beak shape.

The technique described in the passage, where animals are intentionally crossed to produce offspring with specific qualities, is known as selective breeding. This process involves humans selecting and mating animals that possess desirable traits in order to pass those traits onto future generations. This is different from natural selection, which is the process where organisms with advantageous traits are more likely to survive and reproduce in their natural environment. Gene replication and random mutation are not accurate descriptions of this technique.

If a characteristic is due to a genetic code that is present in the gametes of the organism, it means that the characteristic can be passed on to future generations through reproduction. This is important for evolution because it allows the characteristic to become more prevalent in the population over time. Characteristics that are not present in the gametes, such as those acquired during an organism's lifetime, cannot be inherited and therefore do not directly affect the evolution of the species.

The answer is Earthworms and sea stars have a common ancestor. This can be inferred from the diagram representing evolutionary relationships between groups of organisms. The diagram likely shows a branching pattern, with different groups of organisms stemming from a common ancestor. Therefore, it can be concluded that earthworms and sea stars share a common ancestor.

During DNA replication, the base subunit sequence can be altered, leading to variations within an organism. These variations can result in genetic diversity, which is important for the survival and adaptation of a species. It allows for the introduction of new traits and the potential to better withstand changes in the environment. This variation can occur through mutations, which can be beneficial, harmful, or have no effect on the organism. Therefore, a change in the base subunit sequence during DNA replication can lead to variation within an organism.

The statement "Natural selection played a role in the development of this protective coloration" provides a possible biological explanation for the resemblance between certain insects and the bark of the trees they live on. Natural selection is the process by which individuals with advantageous traits are more likely to survive and reproduce, passing on those traits to future generations. In this case, the insects that had protective coloration similar to the tree bark would have been better able to hide from predators, increasing their chances of survival. Over time, this trait would have become more common in the population due to natural selection.

The given observations of the Bird of Paradise species in the jungles of New Guinea, where males exhibit unique courtship behaviors to attract females, support the concept that behaviors that lead to reproductive success have evolved. This is because the males' shaking of their bodies and hanging upside down, along with their bright colors and long feathers, are traits that have been selected for over time due to their ability to attract mates and increase the chances of successful reproduction.

The correct answer is soft-bodied organisms --> fish --> amphibians --> mammals. This sequence represents the most accepted understanding of the evolution of life on Earth based on the fossil record. Soft-bodied organisms were among the earliest forms of life, followed by the emergence of fish. Amphibians then evolved from fish, and mammals evolved from amphibians. This sequence aligns with the gradual development and diversification of different species over time.

The diagram represents four different species of wild birds with feet that have different structural adaptations. The best explanation for the development of these adaptations is natural selection. Natural selection is the process by which organisms with traits that are advantageous for their environment have a higher chance of survival and passing on their genes to the next generation. Over time, this leads to the accumulation of traits that are well-suited for the species' specific needs and environment. In this case, the different structural adaptations in the birds' feet likely evolved through natural selection to help them better survive and thrive in their respective habitats.