Question 1

The following questions refer to the description below.
There are many advantages for plants to living in an aqueous environment.For example,water provides support,the temperature of water fluctuates much less than on land,and external fertilization is facilitated in water.Nevertheless,plants successfully invaded land and diversified.
-What evidence in the fossil record would you look for that would indicate that plants had successfully colonized land?

Accepted Answer

The answer of The following questions refer to the description...

Question 2

The next few questions are based on the following description.
A biology student hiking in a forest happens upon an erect,15-cm-tall plant that bears microphylls and a strobilus at its tallest point.When disturbed,the cone emits a dense cloud of brownish dust.A pocket magnifying glass reveals the dust to be composed of tiny spheres with a high oil content.
-This organism probably belongs to the same phylum as the

Accepted Answer

The description mentions microphylls and a strobilus, which are both characteristics of the phylum Lycophyta (club mosses, quillworts, and spike mosses). The dense cloud of brownish dust is likely spores, which are also characteristic of this phylum. Ferms, horsetails, and whisk ferns have megaphylls instead of microphylls, while mosses, hornworts, and liverworts do not have strobili. Conifers belong to the phylum Coniferophyta, and charophytes are green algae.

Question 3

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 4

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 nutrient uptake, so it is unlikely that they would have reduced nitrogen loss by erosion. Rhizoids help stabilize the soil and protonemata absorb and store nutrients, so choices A and B are both plausible. The gametophore mat can slow water entry and reduce erosion, making choice C also a possible explanation.

Question 5

The next few questions are based on the following description.
A biology student hiking in a forest happens upon an erect,15-cm-tall plant that bears microphylls and a strobilus at its tallest point.When disturbed,the cone emits a dense cloud of brownish dust.A pocket magnifying glass reveals the dust to be composed of tiny spheres with a high oil content.
-This student has probably found a(n)

Accepted Answer

The presence of microphylls and a strobilus at the tallest point, as well as the emission of dense cloud of brownish dust composed of tiny spheres with high oil content, suggests that the student has found a lycophyte sporophyte.

Question 6

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

The trend from dominant gametophytes to dominant sporophytes would have been noticeable over this period, as well as the trend from no true leaves to microphylls to megaphylls. Additionally, there was a trend from soil-surface-hugging plants to "overtopping" plants and an increase in the lignification of conducting systems. The only trend not mentioned is the shift from sporangia borne on modified leaves (sporophylls) to sporangia borne on stalks (seta).

Question 7

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 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.
 
-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

The correct sequence to test the hypothesis would be to first establish two identical plots of Polytrichum mosses (step 5). Then, measure the initial soil nitrogen contents of control and experimental plots (step 3). Next, add metabolic poison to the soil of the experimental plot of mosses (step 1). After that, apply water equally to the experimental and control plots (step 2). Finally, determine nitrogen loss from soil of control and experimental plots (step 4). This sequence allows for the controlled testing of the effect of dead Polytrichum rhizoids on reducing soil nitrogen loss.

Question 9

The next few questions are based on the following description.
A biology student hiking in a forest happens upon an erect,15-cm-tall plant that bears microphylls and a strobilus at its tallest point.When disturbed,the cone emits a dense cloud of brownish dust.A pocket magnifying glass reveals the dust to be composed of tiny spheres with a high oil content.
-Besides oil,what other chemical should be detected in substantial amounts upon chemical analysis of these small spheres?

Accepted Answer

The presence of a strobilus and microphylls indicate that this is a lycophyte, which produces spores with a high content of sporopollenin. The tiny spheres with high oil content are likely spores, which would also contain sporopollenin. Therefore, upon chemical analysis of these spheres, sporopollenin should be detected in substantial amounts.

Question 10

Use the following figure to answer the questions below.
 
-Which of the following should be most helpful in distinguishing the clades depicted on the tree in the above figure from each other?

Accepted Answer

The answer of Use the following figure to answer the...

Question 11

Use the following figure to answer the questions below.
 
-What is true of the phylogenetic tree in the figure above?
1)It depicts uncertainty about whether the bryophytes or the vascular plants evolved first.
2)It is hypothetical.
3)It includes polytomies.
4)It shows that ferns (phylum Pterophyta)are the closest living relatives to the seed plants.
5)It indicates that seeds are a shared ancestral character of all vascular plants.

Accepted Answer

The answer of Use the following figure to answer the...

Question 12

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 13

The next few questions are based on the following description.
A biology student hiking in a forest happens upon an erect,15-cm-tall plant that bears microphylls and a strobilus at its tallest point.When disturbed,the cone emits a dense cloud of brownish dust.A pocket magnifying glass reveals the dust to be composed of tiny spheres with a high oil content.
-A dissection of the interior of this organism's stem should reveal

Accepted Answer

The presence of microphylls and a strobilus indicates that this plant is a lycophyte, a group known for possessing lignified vascular tissues in their stems.

Question 14

The following questions refer to the description below.
There are many advantages for plants to living in an aqueous environment.For example,water provides support,the temperature of water fluctuates much less than on land,and external fertilization is facilitated in water.Nevertheless,plants successfully invaded land and diversified.
-Which problem with growing on land does not fit with the adaptation to survive dry terrestrial conditions?

Accepted Answer

Rhizoids are root-like structures that provide anchorage in aquatic environments. They are not necessary for the transport of water on land where vascular systems evolved to perform this function.

Question 15

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 16

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 17

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

Bryophyta (mosses), Pterophyta (ferns), Lycophyta (club mosses), and Chlorophyta (green algae) all have flagellated sperm. Angiosperms (flowering plants) do not have flagellated sperm.

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

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

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

Question 20

Use the following figure to answer the questions below.
 
-The resolution of the relationships indicated by dashed lines in the figure above will most probably come from

Accepted Answer

The dashed lines in the figure represent unresolved relationships, meaning that there is not enough evidence to determine exactly how these groups are related. Whole-genome analyses of extant species could provide more data on shared genetic traits that would help determine the relationships among these groups. More detailed analyses of morphologies or life cycles may not be enough to distinguish between these groups, and the discovery of more fossils may help fill in some gaps but may not be sufficient to resolve the relationships indicated by dashed lines. The structures of photosynthetic pigments are also unlikely to provide enough information to resolve these relationships.

Quiz 29: Plant Diversity I: How Plants Colonized Land

Use the following figure to answer the questions below. -Which of the following should be most helpful in distinguishing the clades depicted on the tree in the above figure from each other?

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 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?

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

Use the following figure to answer the questions below. -The resolution of the relationships indicated by dashed lines in the figure above will most probably come from