7. look at the representation of a hillside below. the symbols in each stratus of the cross-section represent fossils of different organisms. which of the following organisms must have evolved first?
% * ^ ^ *
% $ $ $ # # # * * * * *
$ * * * $ $ # # # # @
% # # # @ @ ! ! ! ! * *
@ < < < < < + + + + = =
a. $
b. #
c. *
d. @

Which of the following descriptions of proteins are true? i. proteins can have different sequences of amino acids. ii. proteins can have different shapes. iii. proteins can have different numbers of amino acids. a. only i and ii are true. b. only ii and iii are true. c. only i and iii are true. d. i and ii and iii are all true. e. none are true statements

How are the testes and ovaries similar? a. both produce sex cells. b. both connect internal reproductive organs to the exterior. c. both transport sex cells from their site of production. d. both store mature sex cells.

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above