Classification of Organisms
Question: What is the science of naming and classifying organisms called?
Answer: Taxonomy.
Question: What is the study of fossils called?
Answer: Paleontology.
Question: What are structures with similar underlying anatomy but different functions called?
Answer: Homologous structures.
Question: What was the name of the ship on which Charles Darwin travelled in 1831?
Answer: HMS Beagle.
What are the two main sources of inherited variation
Mutations and sexual reproduction
Question: What are the two parts of a scientific name in binomial nomenclature?
Answer: Genus and species.
Question: What is the term for the time required for half of a radioactive parent isotope to decay?
Answer: Half-life.
Question: The wings of birds and insects perform the same function but have different underlying structures. What are these structures called?
Answer: Analogous structures.
Question: Which scientist proposed that organisms could pass acquired characteristics to their offspring?
Answer: Jean-Baptiste Lamarck.
Question: What is the formation of new species called?
Answer: Speciation.
Question: List the seven levels of classification from broadest to most specific.
Answer: Kingdom, Phylum, Class, Order, Family, Genus, Species.
Question: Which type of rock is most likely to contain fossils?
Answer: Sedimentary rock.
Question: What are vestigial structures? Give one example.
Answer: Reduced structures that have lost most or all of their original function. Example: hip and leg bones in whales.
Question: Which scientist independently developed a theory of natural selection similar to Darwin's?
Answer: Alfred Russel Wallace.
Question: What type of speciation occurs when a physical barrier separates a population?
Answer: Allopatric speciation.
Question: What is the main difference between prokaryotic and eukaryotic cells?
Answer: Prokaryotic cells lack a true nucleus, while eukaryotic cells have a true nucleus.
Question: A radioactive sample originally contained 200 g of a parent isotope. After two half-lives, how much parent isotope remains?
Answer: 50 g.
200 g → 100 g → 50 g.
Question: Scientists compare the amino acid sequences of hemoglobin in two species. What does a smaller number of differences suggest about their evolutionary relationship?
Answer: The species are more closely related and share a more recent common ancestor.
Question: According to Darwin's theory of natural selection, why do individuals with favourable inherited variations become more common in a population over generations?
Answer: They are more likely to survive and reproduce successfully, passing their favourable variations to their offspring.
Question: What is the difference between gradualism and punctuated equilibrium?
Answer: Gradualism involves slow, continuous evolutionary change, while punctuated equilibrium involves relatively rapid changes followed by long periods of little or no change.
Question: Two organisms have the scientific names Ursus americanus and Ursus arctos. What can you conclude about their classification?
Answer: They belong to the same genus (Ursus) but are different species.
Question: A rock sample contains 25 g of a radioactive parent isotope and 75 g of its daughter isotope. Assuming no daughter isotope was present initially and none was lost, how many half-lives have passed?
Answer: Two half-lives.
The original 100 g of parent isotope decreased to 50 g, then to 25 g.
Question: Cabbage, broccoli, cauliflower, and ornamental kale were developed from the same ancestral plant through selective breeding. What process does this demonstrate?
Answer: Artificial selection.
Question: Lamarck and Darwin proposed different explanations for giraffes having long necks. How would each scientist explain this characteristic?
Answer: Lamarck proposed that giraffes stretched their necks to reach food and passed the acquired length to their offspring. Darwin proposed that giraffes with inherited longer necks had a survival and reproductive advantage, making this trait more common over generations.
Question: Explain how mutations and natural selection can lead to the formation of a new species after a population becomes geographically isolated.
Answer: Mutations introduce new genetic variations. Natural selection acts independently on the isolated populations. Over many generations, inherited differences may accumulate until the populations can no longer interbreed successfully, resulting in new species.