Biology 0610 · IGCSE · Chromosomes, genes and proteins
Chromosomes, genes and proteins — practice question
Organisms may be classified using their characteristics and by examining the order of bases in their DNA.
Fig. 5.1 is a diagram that illustrates the evolutionary relationships among several different groups of organisms. Each branch marks the point where organisms acquired new features that place them in a new group. The place where a branch begins also shows the common ancestor shared by the new groups.
(a(i))[2]
Suggest which visible features developed at A and B in Fig. 5.1.
(a(ii))[1]
Identify the names of the two groups that have the most recent common ancestor in Fig. 5.1.
(a(iii))[2]
Suggest the groups whose DNA base sequences are most similar and least similar to crocodiles in Fig. 5.1.
most similar [BLANK]
least similar [BLANK]
(b)[4]
Describe the structure of a DNA molecule.
(c)[3]
Outline how the base sequences in DNA control cell function.
Worked solution & mark scheme
This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: “A - hair / external ears” …