2> nonpolar substances b. hydrophobic
3> ionic substances c. hydrophilic
14) the fact that a nucleic acid is a very complicated molecule suggests that
a. the rna-first hypothesis is impossible.
b. rna could not have arisen on its own by chance, but required enzymes to guide the
synthesis of nucleotides and then nucleic acids.
c. sophisticated enzymes were not present or available to synthesize it.
d. no natural system could ever generate it.
e. the protein-first hypothesis is therefore the only plausible hypothesis.
15) hair is a character shared by all mammals, but not found in their ancestral lineage.
hair is therefore considered to be a(n)
a. clade.
b. shared ancestral character (trait).
c. shared derived character (trait).
d. analogous structure.
16) to what does the term chiasma refer?
a. the process of fertilization
b. the life cycle of a fungus
c. the process of crossing-over
d. a structure that holds together homologues during crossing-over
e. the period between meiosis i and meiosis ii
17) the organ that exchanges molecules between fetal and maternal blood is the
a. vagina.
b. oviduct.
c. uterus.
d. placenta.
e. mammary gland.