Question 1

Which of the following are land plants that use the same means of getting sperm to egg that algae use?

Accepted Answer

True mosses, hornworts, and liverworts (A) as well as ferns, whisk ferns, and horsetails (B) both use water as a medium for sperm to swim to the egg, similar to algae.

Question 2

Increasing the number of stomata per unit surface area of a leaf when atmospheric CO₂ levels decline is most analogous to a human

Accepted Answer

Just as plants increase the number of stomata to absorb more CO₂ when levels decline, humans increase the number of red blood cells (RBCs) in circulation to carry more oxygen when atmospheric O₂ levels decline. Both responses aim to increase the efficiency of gas exchange.

Question 3

Which of the following should have had gene sequences most similar to the charophyte that was the common ancestor of the land plants?

Accepted Answer

Early bryophytes (e.g. liverworts, mosses) are the closest extant relatives of the first land plants that evolved from charophyte algae. Therefore, their gene sequences should be most similar to the charophyte ancestor.

Question 4

Refer to the following information to answer the next few questions.
Researchers decided to test the hypothesis that if the 2-m tall Polytrichum gametophyte- sporophyte plants had acted as a physical buffer, then they would have reduced water's ability to erode the soil and carry away its nitrogen. They began with four equal-sized areas where Polytrichum mosses grew to a height of 2 m above the soil surface. One of the four areas was not modified. In the second area, the mosses were trimmed to a height of 1 m above the soil surface. In the third area, the mosses were trimmed to a height of 0.5 m above the soil surface. In the fourth area, the mosses were trimmed all the way to the ground, leaving only the rhizoids. Water, simulating rainfall, was then added in a controlled fashion to all plots over the course of one year. The figure below presents four graphs that depict potential results of this experiment.
 
-Which of these potential results of applying a metabolic poison to the rhizoids of Polytrichum should interfere the least with the ability to draw valid conclusions from this experiment?

Accepted Answer

If the metabolic poison acts against the mitochondria of the rhizoid cells, it would not interfere with the ability to draw valid conclusions from the experiment because the researchers are primarily interested in the physical buffering effect of the Polytrichum mosses on erosion and nitrogen loss, rather than the metabolic functioning of its rhizoids.

Question 5

Which of the following is true of seedless vascular plants?

Accepted Answer

Whole forests were dominated by large, seedless vascular plants during the Carboniferous period. This is a well-known fact about seedless vascular plants from the fossil record. The other choices are false: A is not necessarily true, C is false because spores and seeds are different structures, D is false because the sporophyte is the dominant generation, and E is false because Sphagnum is a type of moss, not a seedless vascular plant.

Question 6

Of the following list, flagellated (swimming)sperm are generally present in which groups? 1. Lycophyta
2. Bryophyta
3. Angiosperms
4. Chlorophyta
5. Pterophyta

Accepted Answer

Flagellated (swimming) sperm are generally present in groups that rely on water for fertilization, including Lycophyta (club mosses), Bryophyta (mosses), Chlorophyta (green algae), and Pterophyta (ferns). Angiosperms (flowering plants) typically do not have flagellated sperm, as they rely on other mechanisms for fertilization, such as pollination by animals or wind.

Question 7

Assuming that they all belong to the same plant, arrange the following structures from largest to smallest (or from most inclusive to least inclusive). 1. spores
2. sporophylls
3. sporophytes
4. sporangia

Accepted Answer

The correct order from most inclusive to least inclusive is sporophytes (3), sporophylls (2), sporangia (4), and spores (1). Sporophytes are the diploid generation that produces spores, sporophylls are leaves that bear sporangia, sporangia are structures that produce spores, and spores are the actual reproductive units.

Question 8

Refer to the following information to answer the next few questions.
Researchers decided to test the hypothesis that if the 2-m tall Polytrichum gametophyte- sporophyte plants had acted as a physical buffer, then they would have reduced water's ability to erode the soil and carry away its nitrogen. They began with four equal-sized areas where Polytrichum mosses grew to a height of 2 m above the soil surface. One of the four areas was not modified. In the second area, the mosses were trimmed to a height of 1 m above the soil surface. In the third area, the mosses were trimmed to a height of 0.5 m above the soil surface. In the fourth area, the mosses were trimmed all the way to the ground, leaving only the rhizoids. Water, simulating rainfall, was then added in a controlled fashion to all plots over the course of one year. The figure below presents four graphs that depict potential results of this experiment.
 
-Why should we expect the soil's nitrogen not to be contained solely within the rhizoids of the Polytrichum mosses?

Accepted Answer

Rhizoids are not absorptive structures, but rather serve to anchor the moss in place and absorb water. Therefore, it is unlikely that the moss's nitrogen would be solely contained within rhizoids.

Question 9

Refer to the following information to answer the next few questions.
Researchers decided to test the hypothesis that if the 2-m tall Polytrichum gametophyte- sporophyte plants had acted as a physical buffer, then they would have reduced water's ability to erode the soil and carry away its nitrogen. They began with four equal-sized areas where Polytrichum mosses grew to a height of 2 m above the soil surface. One of the four areas was not modified. In the second area, the mosses were trimmed to a height of 1 m above the soil surface. In the third area, the mosses were trimmed to a height of 0.5 m above the soil surface. In the fourth area, the mosses were trimmed all the way to the ground, leaving only the rhizoids. Water, simulating rainfall, was then added in a controlled fashion to all plots over the course of one year. The figure below presents four graphs that depict potential results of this experiment.
 
-If the actual results most closely resembled those in part (A)of the figure, then a further question arising from these data is: "Do the Polytrichum rhizoids have to be alive in order to reduce soil nitrogen loss, or do dead rhizoids have the same effect?" Arrange the following steps in the correct sequence to test this hypothesis. 1. Add metabolic poison to the soil of the experimental plot of mosses.
2. Apply water equally to the experimental and control plots.
3. Measure initial soil nitrogen contents of control and experimental plots.
4. Determine nitrogen loss from soil of control and experimental plots.
5. Establish two identical plots of Polytrichum mosses; one as a control, the other as the experimental treatment.

Accepted Answer

To test the hypothesis, two identical plots of Polytrichum mosses need to be established (step 5), one as a control and the other as an experimental treatment. Then, the metabolic poison needs to be added to the soil of the experimental plot of mosses (step 1). The initial soil nitrogen contents of the control and experimental plots need to be measured (step 3), followed by applying water equally to the experimental and control plots (step 2). Finally, the nitrogen loss from soil of the control and experimental plots needs to be determined (step 4). This order allows for a valid experimental design to determine the effect of living versus dead rhizoids in reducing soil nitrogen loss.

Question 10

During glacial periods in the early evolution of land plants, which of the following would have been a beneficial adaptation regarding the number of stomata per unit surface area, and what accounts for it?

Accepted Answer

During glacial periods, atmospheric CO2 levels were lower, so plants with more stomata could absorb CO2 more efficiently, which was crucial for photosynthesis.

Question 11

If a fern gametophyte is a hermaphrodite (that is, has both male and female gametangia on the same plant), then it

Accepted Answer

Ferns are homosporous, meaning they produce a single type of spore that gives rise to a gametophyte that is typically hermaphroditic. Therefore, a fern gametophyte with both male and female gametangia would be homosporous.

Question 12

Arrange the following terms from most inclusive to least inclusive. 1. embryophytes
2. green plants
3. seedless vascular plants
4. ferns
5. tracheophytes

Accepted Answer

Green plants are the most inclusive term that includes all plants that can perform photosynthesis. Tracheophytes are the next most inclusive term, referring to plants that have specialized tissues for conducting water and nutrients. Embryophytes refer to all land plants that produce embryos, including both seed and non-seed plants. Seedless vascular plants are a subcategory of tracheophytes that do not produce seeds, but reproduce via spores. Ferns are a specific type of seedless vascular plant. Therefore, the correct order from most inclusive to least inclusive is: 2, 1, 5, 3, 4.

Question 13

Refer to the following information to answer the next few questions.
Researchers decided to test the hypothesis that if the 2-m tall Polytrichum gametophyte- sporophyte plants had acted as a physical buffer, then they would have reduced water's ability to erode the soil and carry away its nitrogen. They began with four equal-sized areas where Polytrichum mosses grew to a height of 2 m above the soil surface. One of the four areas was not modified. In the second area, the mosses were trimmed to a height of 1 m above the soil surface. In the third area, the mosses were trimmed to a height of 0.5 m above the soil surface. In the fourth area, the mosses were trimmed all the way to the ground, leaving only the rhizoids. Water, simulating rainfall, was then added in a controlled fashion to all plots over the course of one year. The figure below presents four graphs that depict potential results of this experiment.
 
-Which graph of soil nitrogen loss over time in the figure most strongly supports the hypothesis that if the 2-m tall Polytrichum gametophyte-sporophyte plants had acted as a physical buffer, then they would have reduced water's ability to erode the soil and carry away its nitrogen?

Accepted Answer

The answer of Refer to the following information to answer...

Question 14

Evidence indicates that plants increase the number of stomata in their leaves as atmospheric CO₂ levels decline. Increasing the number of stomata per unit surface area should have the effect of doing which of the following? 1. increase dehydration of leaf tissues
2. decrease dehydration of leaf tissues
3. counter the effect of declining CO₂ on photosynthesis
4. reinforce the effect of declining CO₂ on photosynthesis
5. decrease the O₂ content of air next to the leaves to a level lower than it would otherwise be
6. increase the O₂ content of air next to the leaves to a level higher than it would otherwise be

Accepted Answer

Increasing the number of stomata allows more CO₂ to enter the leaf, countering the effect of declining CO₂ on photosynthesis. However, more stomata also increase water loss, leading to dehydration. Additionally, increased photosynthesis can raise O₂ levels near the leaves.

Question 15

If intelligent extraterrestrials visited Earth 475 million years ago, and then again 300 million years ago (at the close of the Carboniferous period), what trends would they have noticed in Earth's terrestrial vegetation over this period? 1. a trend from dominant gametophytes to dominant sporophytes
2. a trend from sporangia borne on modified leaves (sporophylls)to sporangia borne on stalks (seta)
3. a trend from no true leaves, to microphylls, to megaphylls
4. a trend from soil-surface-hugging plants to "overtopping" plants
5. a trend toward increased lignification of conducting systems

Accepted Answer

Intelligent extraterrestrials visiting Earth 475 million years ago would have observed a trend from dominant gametophytes to dominant sporophytes, as this is the time when land plants were transitioning from the gametophyte-dominant life cycle to the sporophyte-dominant life cycle. Similarly, the extraterrestrials visiting Earth again 300 million years ago (at the close of the Carboniferous period) would have observed the same trend continuing.

Furthermore, they would have noticed a trend from no true leaves, to microphylls, to megaphylls as land plants evolved to have more complex vascular systems and larger leaves for photosynthesis.

They would have also observed a trend from soil-surface-hugging plants to "overtopping" plants, as plants evolved structures such as stems and leaves to compete for sunlight and gain an advantage in reproductive success.

Finally, they would have noticed a trend toward increased lignification of conducting systems, as plants evolved lignified tracheids and vessels to transport water and nutrients more efficiently.

Question 16

Refer to the following information to answer the next few questions.
Researchers decided to test the hypothesis that if the 2-m tall Polytrichum gametophyte- sporophyte plants had acted as a physical buffer, then they would have reduced water's ability to erode the soil and carry away its nitrogen. They began with four equal-sized areas where Polytrichum mosses grew to a height of 2 m above the soil surface. One of the four areas was not modified. In the second area, the mosses were trimmed to a height of 1 m above the soil surface. In the third area, the mosses were trimmed to a height of 0.5 m above the soil surface. In the fourth area, the mosses were trimmed all the way to the ground, leaving only the rhizoids. Water, simulating rainfall, was then added in a controlled fashion to all plots over the course of one year. The figure below presents four graphs that depict potential results of this experiment.
 
-The 2-m height attainable by Polytrichum moss is at the upper end of the size range reached by mosses. What accounts for the relative height of Polytrichum?

Accepted Answer

Polytrichum moss can attain greater heights due to the presence of conducting tissues in the "stem," which allow for more efficient transport of water and nutrients, supporting taller growth.

Question 17

If you were faced with the choice of eliminating all mutualistic symbioses involving plants and other organisms (besides humans), with the goal being to preserve the most plant biomass, which of the following would you save from elimination?

Accepted Answer

The answer of If you were faced with the choice...

Question 18

What is thought to be the correct sequence of the following events during the Carboniferous period? 1. vascular plants become more prevalent
2. megaphylls with large surface areas become more prevalent
3. atmospheric CO₂ levels decline by a factor of five
4. global cooling occurs, leading to widespread glaciations

Accepted Answer

The correct sequence starts with vascular plants becoming more prevalent, which then leads to the development of megaphylls with large surface areas. This increase in plant life and leaf surface area contributes to a significant decline in atmospheric CO₂ levels, as plants absorb CO₂ for photosynthesis. The reduction in CO₂ levels then leads to global cooling and widespread glaciations.

Question 19

If humans had been present to build log structures during the Carboniferous period (they weren't), which plant types would have been suitable sources of logs?

Accepted Answer

During the Carboniferous period, which occurred between 359 and 299 million years ago, ferns, horsetails, and lycophytes were the dominant plant types. These types of plants would have been suitable sources for log structures if humans had been present to build them. Whisk ferns, epiphytes, bryophytes, charophytes, and gymnosperms were not dominant plant types during this time period and therefore would not have been suitable sources of logs.

Question 20

Researchers tested nitrogen loss from soil where the moss Polytrichum was growing, and compared it to soil from which Polytrichum had been removed. The data are presented below.
 
-Loss of soil nitrogen via "gaseous emission" was found to be negligible. Rather, most loss of soil nitrogen was due to water erosion of the soil. Which of these hypotheses is least likely to account for the observed results?

Accepted Answer

Sporophyte stomata are not involved in the uptake of soil nutrients and cannot reduce nitrogen loss by erosion. Therefore, this hypothesis is least likely to account for the observed results.

Quiz 29: Plant Diversity I: How Plants Colonized Land

Which of the following are land plants that use the same means of getting sperm to egg that algae use?

Increasing the number of stomata per unit surface area of a leaf when atmospheric CO₂ levels decline is most analogous to a human

Which of the following should have had gene sequences most similar to the charophyte that was the common ancestor of the land plants?

Which of the following is true of seedless vascular plants?

Of the following list, flagellated (swimming) sperm are generally present in which groups? 1. Lycophyta 2. Bryophyta 3. Angiosperms 4. Chlorophyta 5. Pterophyta

Assuming that they all belong to the same plant, arrange the following structures from largest to smallest (or from most inclusive to least inclusive) . 1. spores 2. sporophylls 3. sporophytes 4. sporangia

During glacial periods in the early evolution of land plants, which of the following would have been a beneficial adaptation regarding the number of stomata per unit surface area, and what accounts for it?

If a fern gametophyte is a hermaphrodite (that is, has both male and female gametangia on the same plant) , then it

Arrange the following terms from most inclusive to least inclusive. 1. embryophytes 2. green plants 3. seedless vascular plants 4. ferns 5. tracheophytes

If you were faced with the choice of eliminating all mutualistic symbioses involving plants and other organisms (besides humans) , with the goal being to preserve the most plant biomass, which of the following would you save from elimination?

If humans had been present to build log structures during the Carboniferous period (they weren't) , which plant types would have been suitable sources of logs?