Exam-style multiple choice and written questions with full markschemes. Check multiple choice answers straight away, or type, photograph or draw a written answer and get it marked.
Researchers compare a short region of the same gene in three island lizard species. Figure 1 shows the aligned DNA base sequences.
Determine the number of base differences between species P and species R in Figure 1.
Identify the pair of species with the most similar DNA sequences and state the number of base differences between them.
Explain why the similar DNA sequences of this pair provide evidence of common ancestry.
In a beetle population, 20% of adults have dark shells before the substrate darkens. After the change, 70% of the same adults have dark shells. Adults of both shades contribute equally to an offspring cohort, of which 20% have dark shells when raised on the original substrate. Which interpretation applies the definition of evolution to shell shade?
Answer: C. Evolution is a change in the heritable characteristics of a population, not a change acquired by individuals during their lives. The proportion of dark-shelled adults rises from 20% to 70%, but their offspring, raised on the original substrate, have the initial 20% frequency. Thus, no inherited shift in shell shade is demonstrated. A: treats a change in adult appearance as an evolutionary change in heritable population characteristics. B: applies Lamarckian inheritance, but the offspring do not retain the increase in dark shells. D: confuses some offspring having a characteristic with the frequency of that characteristic changing across generations. Remember: evolution requires a change in heritable population characteristics across generations.
Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.