Which concept of species would be most useful to a field biologist identifying new plant species in a tropical forest?a. biologicalb. ecologicalc. morphologicald. phylogenetic

Add labels to the figure that follows, which illustrates the three steps required for speciation to occur.

What determines the primary structure of a DNA molecule?a. stem-and-loop configurationb. complementary base pairingc. deoxyribonucleotide sequenced. hydrophobic interactions and hydrogen bonding

What type of bond is directly involved in the formation of an α-helix?a. peptide bonds between amino acid residuesb. hydrogen bonds between amino acid residuesc. van der Waals interactions between nonpolar residuesd. disulfide bonds between cysteine residues

According to the punctuated equilibria model,a. given enough time, most existing species will branch gradually into new species.b. most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species.c. most evolution occurs in sympatric populations.d. speciation is usually due to a single mutation.

Select True or False to indicate which of the following groups could be identified using the biological species concept.T/F lizard species living todayT/F sunflower species living todayT/F extinct dinosaursT/F bacteria living today

Molecular zip codes direct molecules to particular destinations in the cell. How are these signals read?a. They bind to receptor proteins.b. They enter transport vesicles.c. They bind to motor proteins.d. They are glycosylated by enzymes.

What type of information is used to direct different polypeptides to fold into different shapes?

Which of the following is an example of a prefertilization barrier to reproduction?a. A female mammal is unable to carry a hybrid offspring to term;b. Hybrid plants produce only sterile pollen;c. A hybrid between two bird species cannot perform a mating display;d. A male fly of one species performs a 'wing-waving' display that does not convince a female of another species to mate with him;e. A hybrid embryo is not able to complete development