AP Biology › Understanding Vascular and Avascular Plants
Which of the following is not an example of an advantage gained through the vascularization of plants?
Swimming sperm
Dominant sporophyte generation
Larger photosynthetic area
Extensive root and shoot systems
Large size
Swimming sperm is a feature of avascular and early vascular plants, who needed to remain in moist environments in order to retain water.
After gaining vascular systems, plants were able to circulate water and nutrients more efficiently, thus being able to grow larger, have more leaves, develop branched systems of roots and shoots to collect water and nutrients, and better dispersal of spores due to gains in size.
Which of the following best describes the pith: a tissue type present in vascular plants?
It is a tissue in vascular plants that transports nutrients throughout the plant
It is a tissue in non-vascular plants that transports nutrients throughout the plant
It contains no parenchyma cells
Pith is located in leaves
Pith is a type of tissue located in the stems of vascular plants. It stores and transports nutrients throughout the plant. The pith is composed of parenchyma cells.
Which of the following structures would be found in a tracheophyte, but not in a bryophyte?
Xylem
Chloroplasts
Cell walls
Plasmids
All plants can be classified as either bryophytes or tracheophytes. Plants that contain transport vessels (xylem and phloem) are tracheophytes, while those without transport vessels are bryophytes. All plants contain cell walls and chloroplasts, but only a tracheophyte would contain xylem. Plasmids are structures that are almost exclusively found in bacteria or protozoans.
Fill in the blanks.
The __________ generation is dominant in the bryophyte life cycles, and the __________ generation is dominant in seedless vascular plants.
gametophyte . . . sporophyte
gametophyte . . . gametophyte
sporophyte . . . gametophyte
sporophyte . . . sporophyte
Bryophytes are nonvascular plants, such as mosses. Gametophytes are species that have haploid cells during their mature lives, while sporophytes are predominantly diploid during their adult phases.
Bryophytes have the gametophyte generation as dominant, with the sporophytes relying on the parental gametophyte. Starting with the evolution of seedless vascular plants, the gametophytes become reduced and are no longer the dominant life cycle. By the formation of angiosperms (seed plants), the gametophytes have become dependent on the parental sporophyte.