Figure 19.1
-Figure 19.1 shows an outcrop of sedimentary rock whose strata are labeled A-D. If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?
A) one stratum
B) two strata
C) three strata
D) four strata

Question

Figure 19.1
-Figure 19.1 shows an outcrop of sedimentary rock whose strata are labeled A-D. If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?
A) one stratum 
B) two strata 
C) three strata 
D) four strata

Quizplus · Accepted Answer

If the fossils of two closely related species are found in stratigraphic sequence, it provides evidence for their evolution. Based on the labeling of strata A-D in Figure 19.1, we can see that the two closely related species (x) can be found in strata B and C. Thus, the correct choice is B, i.e., two strata. The fossils are not present in stratum A or D, as these are the oldest and youngest layers, respectively.

Figure 19.1 -Figure 19.1 Shows an Outcrop of Sedimentary Rock Whose Strata