Question

1 multiple choice 1 point the molecular mechanism by which genetic variation occurs is: speciation natural selection mutations macroevolution 2 multiple choice 1 point which of the following is not observable in nature? natural selection macroevolution speciation adaptation 3 multiple choice 1 point which of the following best describes microevolution? it is the tendency for species to remain unchanged over successive generations. it is the change that occurs when simple organisms develop into very complex organisms it is the change in heritable traits in living populations over successive generations. it is the change in heritable traits in living populations over a single generation. 4 multiple choice 1 point which of the following hypotheses is not a plausible explanation for molecular homology between organisms such as yeast and humans? an intelligent creator designed the same type of molecular machinery in different organisms. a common ancestral organism possessed genes that are seen in both organisms. proteins in a common ancestral organism were reverse transcribed into the homologous dna sequences we observe today.

Explanation:

1. Genetic variation at the molecular level occurs due to mutations, which are changes in the DNA sequence. Speciation is the formation of new species, natural selection acts on existing genetic variation, and macroevolution refers to large - scale evolutionary changes over long periods.
2. Macroevolution is a long - term and large - scale evolutionary process that is not directly observable in nature in the same way as natural selection (e.g., antibiotic resistance in bacteria), speciation (e.g., some plant speciation events), and adaptation (e.g., changes in beak shape in finches).
3. Microevolution is defined as the change in heritable traits in living populations over successive generations. The first option is incorrect as it implies no change. The second option is more related to macroevolution. The fourth option is incorrect because it occurs over successive generations, not a single generation.
4. The idea of an intelligent Creator designing the same molecular machinery is not a scientific hypothesis based on evolutionary theory. A common ancestral organism (option 2) is a fundamental concept in evolution to explain homology. Reverse transcription of proteins from a common ancestor (option 3) is a possible evolutionary mechanism (although less common than direct genetic inheritance from a common ancestor in the context of DNA - based inheritance).

Answer:

1. C. Mutations
2. B. Macroevolution
3. C. It is the change in heritable traits in living populations over successive generations.
4. A. An intelligent Creator designed the same type of molecular machinery in different organisms.