1. Which other scientist independently proposed the same theory of evolution as Charles Darwin ?
Answer
Alfred Russel Wallace.
2. What are fossils ?
Answer
Fossils are the 'remains' (parts/traces) of organisms from millions of years ago, which are found in rocks.
3. Give some reasons why scientists cannot be certain about how life began on Earth.
Answer
Many early forms of life were soft-bodied, which means they left few traces behind, or their traces were destroyed by geological activity.
4. Describe the sources of information that helped Darwin develop his theory.
Answer
His theory was based on developing knowledge of geology and fossils, observations he made during his round-the-world voyage, and years of experimentation and discussion.
5. Give some examples of the works that Wallace is known for.
Answer
Wallace proposed the theory of evolution by natural selection and worked worldwide to gather evidence for evolutionary theory. He is also known for his work on warning coloration in animals and his theory of speciation.
6. Suggest some reasons why the importance of Mendel's discovery was not recognised until after his death.
Answer
The behavior of chromosomes during cell division was not observed until the late nineteenth century. The similarity between chromosomes and Mendel's 'units' was not recognized until the early twentieth century. The structure of DNA was not determined until the mid-twentieth century, and the mechanism of gene function was not worked out until the same period. At that time, most scientists believed in blended inheritance.
7. Describe some actions that should be taken to reduce antibiotic resistance.
Answer
Doctors should not prescribe antibiotics inappropriately, such as for non‑serious or viral infections. Patients should complete their course of antibiotics so that all bacteria are killed and none survive to mutate and form resistant strains. The use of antibiotics in agriculture should also be restricted.
8. In the Galápagos Islands, differences can be observed in the beaks of finches. The finches’ beaks have different shapes, allowing them to eat different types of food. The figure below shows three species of finch and the food they eat. Explain the evolution of the nut-eater beak shapes using Lamarck's theory.
Answer
As the finches ate nuts their beaks got bigger. This bigger beak (acquired characteristic) was passed on to the finches' offspring.
9. Give some ways that human activity could cause the extinction of a species.
Answer
Habitat destruction, global warming, introduction of new predators or pathogens, or pollution.