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Example Questions
Example Question #1 : Plant Biology
Which is of the following is not an adaptation/modification that enabled plants to move from aquatic to terrestrial environments as they evolved?
Roots and root hairs
Stomata
Thylakoid membranes
Cutin
Thylakoid membranes
Thylakoid membranes are found within chloroplasts, which are used for photosynthesis. Plants found in both aquatic and terrestrial environments photosynthesize, so these membranes cannot be considered adaptations uniquely benefiting terrestrial plants.
Comparatively, cutin is a waxy coating found on various parts of plants that helps prevent water loss when exposed to air. Stomata are tiny openings in the epidermis of plants that allow for the exchange of carbon dioxide and oxygen while minimizing water loss. Roots and root hairs allow plants to absorb nutrients and water from the soil. Water loss was the primary challenge plants faced when moving from aquatic to terrestrial environments; cutin, stomata, roots, and root hairs all help terrestrial plants absorb and conserve water.
Example Question #1 : Understanding The Water Land Transition
Which structures did not evolve after plants emerged onto land?
Vascular transport
Seeds
Cell walls
Waxy cuticles
Stomata
Cell walls
Cell walls were present in plant cells before the transition to land. Seeds, stomata, waxy cuticles, and vascular transport all evolved to reduce water loss and circulate water to all areas of the plant. Water loss and circulation were not an issue before the transition to land; plants were forced to adapt these traits in order to survive in a terrestrial environment.
Example Question #2 : Understanding The Water Land Transition
As plants moved from water to land, they developed structures and lifestyles better suited to life in their new environment. Which of the following is not an example of these adaptations?
Vascular tissue
Cuticle
Increase in vertical height
Roots
Decrease in rigidity
Decrease in rigidity
Plants developed more rigid structures to help maintain their growth on land as opposed to water.
Waxy cuticles developed to help reduce water loss/desiccation. Roots allowed plants greater access to water, as well as provided anchoring to the ground; this allowed plants to grow taller. Vascular tissue facilitated transport of water and nutrients to all parts of the plant. Stomata helped with gas exchange.
Example Question #1 : Plant Biology
What is a distinct feature of a C4 plant?
Bundle-sheath cells
Carbon fixation
Light independent reactions
Closed stomata during the day
Bundle-sheath cells
Carbon fixation converts inorganic carbon dioxide into organic carbon compounds, such as glucose and cellulose. This is a characteristic function of both C3 and C4, and is a primary purpose of light independent reactions.
Closed stomata during the day is a characteristic of CAM plants, which allows for the conservation of water that is usually lost during photorespiration.
Bundle-sheath cells are a characteristic of C4 plants. The presence of bundle-sheath cells isolates rubisco, preventing rubisco from binding to oxygen during photorespiration.
Example Question #2 : Plant Biology
Which of the following refers to the principle of alternation of generations in plants?
The need for external pollinators
Gamete-producing sporophytes
A life cycle that includes a multicellular haploid stage
A life cycle which includes a unicellular haploid stage
The differences between a tree and a seed
A life cycle that includes a multicellular haploid stage
Plants have a multicellular haploid stage called the gametophyte. Gametophytes () produce gametes (
) through mitosis, which combine to produce a zygote (
). The zygote grows into a multicellular, diploid sporophyte (
), which produces spores (
) through meiosis. Those spores give rise to multicellular gametophytes.
Example Question #1 : Understanding Other Plant Evolution
How is it believed that plants first became photosynthetic?
The origin of the chloroplast is still largely unknown
A vacuole became specialized for photosynthesis
The chloroplast was a cluster of synthesized proteins, which evolved over time
An ancestor of modern plants internalized a photosynthetic prokaryote through phagocytosis
An ancestor of modern plants internalized a photosynthetic prokaryote through phagocytosis
The chloroplast is believed to have evolved from photosynthetic bacteria that formed a mutualistic symbiotic relationship with an ancestor of plants through endosymbiosis. There is lots of evidence supporting the endosymbiotic theory, which is based on the principle of one organism phagocytosing another, resulting in mutualism.
Example Question #1 : Understanding Other Plant Evolution
Mutualistic relationships between angiosperms and biotic pollinators foster which of the following types of evolution?
Divergent evolution
Convergent evolution
Speciation
Co-evolution
Co-evolution
Biotic pollinators, such as bees and hummingbirds, share a mutualistic relationship with angiosperms. This leads to co-evolution, in which the selective pressure of one species impacts the genetic composition of another. In this case, the preferences of the pollinators impact the reproductive success of specific angiosperms.
Example Question #1 : Classes Of Plant
Fill in the blanks.
The __________ generation is dominant in the bryophyte life cycles, and the __________ generation is dominant in seedless vascular plants.
sporophyte . . . sporophyte
sporophyte . . . gametophyte
gametophyte . . . gametophyte
gametophyte . . . sporophyte
gametophyte . . . 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.
Example Question #1 : Understanding Vascular And Avascular Plants
Which of the following structures would be found in a tracheophyte, but not in a bryophyte?
Chloroplasts
Xylem
Plasmids
Cell walls
Xylem
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.
Example Question #2 : Classes Of Plant
Which of the following is not an example of an advantage gained through the vascularization of plants?
Larger photosynthetic area
Extensive root and shoot systems
Swimming sperm
Large size
Dominant sporophyte generation
Swimming sperm
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.
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