The fossil record shows that the first eukaryotes may have appeared on Earth (1 point) A. more than 4 billion years ago. B. more than 1 billion years ago. C. about 500 million years ago. D. about 100 million years ago.

Refer to this portion of a dichotomous key for fish identification to answer the question. 1. (a) has a single dorsal fin ® 5 (b) has a double dorsal fin ® 2 2. (a) one fin is spiny, the other is smooth ® 3 (b) one fin is not spiny or smooth ® 4 5. (a) has small fin on back near tail ® 6 (b) has no fin on back near tail ® 7 6. (a) has barbs near the mouth ® catfish (b) does not have barbs near the mouth ® 10 7. (a) tail is asymmetrical ® 8 (b) tail is symmetrical ® 9 10. (a) scales are small ® trout (b) scales are large ® whitefish what is the next step to complete to identify a fish that has a single dorsal fin, no fin on the back near the tail, and no barbs near the mouth? step 2 step 5 step 7 step 10

What was the impact of the concordat of worms?

Which of the following would involve looking at different structures of organisms and comparing how similar they are? a. vestigial structuresb. radiometric datingc. homologous structures