The sporophytes of mosses depend on the gametophytes for water and nutrition. In seed plants, the reverse is true. From which seed plant sporophyte structure(s) do the immature (unfertilized) gametophytes directly gain water and nutrition?
Which of the following is an ongoing trend in the evolution of land plants?
b. reduction of the gametophyte phase of the life cycle
All of the following cellular structures are found in cells of angiosperm and gymnosperm gametophytes except
Plants with a dominant sporophyte are successful on land partly because
d. their gametophytes are protected by, and obtain nutrition from, the sporophytes.
Seeds commonly provide for each of the following except
e. desiccation resistance.
In addition to seeds, which of the following characteristics are unique to the seed-producing plants?
Which of the following most closely represents the male gametophyte of seed-bearing plants?
c. pollen grain
Suppose that the cells of seed plants, like the skin cells of humans, produce a pigment upon increased exposure to UV radiation. Rank the cells below, from greatest to least, in terms of the likelihood of producing this pigment.
c. 3, 1, 4, 2
Which number represents the mature gametophyte?
Which number represents an embryo?
Meiosis is most likely to be represented by which number(s)?
Which number represents a megaspore mother cell?
Which numbers represent haploid cells or tissues?
e. 5, 7, and 9
The process labeled "6" involves
The embryo sac of an angiosperm flower is best represented by which number?
In angiosperms, which number represents the event that initiates the formation of endosperm?
In seed plants, which structure or material is considered part of a pollen grain?
In terms of alternation of generations, the pollen grains of seed-producing plants are most similar to a
e. fern gametophyte that will bear only antheridia.
Which of these is most important in making the typical seed more resistant to adverse conditions than the typical spore?
Gymnosperms differ from both extinct and extant ferns because they