The tough outer layer of a seed is called the
a. nut.
b. seed coat.
c. fruit. d. embryo wall.

Plants can respond to changing environmental conditions by the use of which chemicals?
a. hormones
b. enzymes
c. pigments d. sugars

A seed that is dispersed to an area far away from the parent plant might face less
a. germination.
b. alternation.
c. pollination.
d. competition.



Which of the following is NOT a characteristic of all plants?
a. produce seeds
b. are eukaryotic
c. have cell walls
d. are multicellular

Seeds dispersed by animals typically are contained in
a. thin coatings that are easily digested.
b. fleshy, nutritious fruits.
c. lightweight structure
d. unripened ovaries.