"a major function of structure x is to
(1)produce gametes by meiosis
(2)protect the fetus from physical injury
(3)exchange materials between the mother and the fetus
(4)store food to provide the fetus with nutrient"

List the advantages and disadavantages of the switch from persistent chlorinated hydrocarbon pesticides (such as ddt) to nonpersistent organophosphate pesicides. have the benefits of the switch outweighed the disadvantages? explain.

Restriction enzymes are used in making recombinant dna. describe the role restriction enzymes perform when constructing recombinant dna.

The green colored pigment in chloroplasts is? a. nitrogen b. chlorophyll c. chlorophorm d. chlorofloromethane