A gene that keeps switchgrass forever young could have far-reaching

Question

A gene that keeps switchgrass forever young could have far-reaching implications for the development of the plant as a biofuel crop, according to U.S. Department of Agriculture (USDA) scientists.

Inserting a specific gene called corngrass from corn into switchgrass essentially keeps the perennial grass in its juvenile form—a plant that doesn’t flower, doesn’t produce seeds, and doesn’t have a dormant growth phase. Because of these changes, the sugars making up the plant starch are more readily available for conversion into cellulosic ethanol.

According to Agricultural Research Service (ARS) geneticist Sarah Hake, the starch in these transgenic plants stays inside the stem because it isn’t needed elsewhere for nourishing flower buds and blossoms. As a result, starch levels can increase as much as 250%, which increases the sugars that can be fermented into ethanol.

Hake, director of the ARS Plant Gene Expression Center in Albany, CA, teamed with University of California–Berkeley plant geneticist George Chuck to conduct this investigation. ARS is the USDA’s chief intramural scientific research agency, and this work supports the USDA priority of developing new sources of bioenergy.

The scientists observed that the leaves in the transgenic switchgrass are not nearly as stiff as leaves in switchgrass cultivars that haven’t been modified. In addition, they determined that leaf lignin is slightly different in the transgenic switchgrass than leaf lignin in other plants. This could lead to new findings on how to break down the sturdy lignin and release sugars for fermentation, a development that will be essential to the commercial production of cellulosic ethanol.

The researchers are now introducing DNA segments called genetic promoters that would “turn on” the expression of the corngrass gene in aboveground switchgrass shoots. This could help increase root mass development that otherwise would be inhibited by the gene. Hake and Chuck also suggest that developing nonflowering switchgrass varieties would eliminate the possibility of cross-pollination between transgenic switchgrass cultivars and other switchgrass cultivars.    1 
 1. The following are all side effects of the modified switchgrass EXCEPT:

a. stiffer leaves 
b. infertility 
c. dormant growth 
d. inability to flower 
e. higher sugar levels

2 
 2. The passage suggests that the development of transgenic switchgrass will

a. eliminate the need to farm corn. 
b. support the USDA’s priority of finding alternative fuel sources. 
c. strengthen the plant lignin. 
d. introduce new DNA segments. 
e. pit the Department of Agriculture against the Plant Gene Expression Center.

3 
 3. The passage’s primary function is to

a. criticize the work of an institution. 
b. compare two possible solutions when only one is needed. 
c. provide the outcome of a finished study. 
d. optimistically deliver the findings of a study in progress. 
e. eliminate assumptions that are not critical to the findings.

4 
 4. Geneticist Sarah Hake heads the

a. U.S. Department of Agriculture. 
b. University of California–Berkeley. 
c. corngrass study. 
d. Plant Gene Expression Center. 
e. Agricultural Research Center.

5 
 5. Which of the following would be most interested in the study?

a. corn farmers 
b. Orville Redenbacher 
c. alternative energy car manufacturers 
d. the president of the United States 
e. DNA specialists

6 
 6. Which of the following inferences can be drawn based on the information provided in the passage?

a. The USDA has previously neglected its duty to prioritize the development of biofuels. 
b. Our society is becoming more open to the idea of widespread use of genetically engineered products. 
c. We will inevitably drain all our fuel sources, forcing the prioritization of the USDA to produce more. 
d. The development of switchgrass can lead to a lot of promising uses from different avenues. 
e. The cross-pollination of different variants of switchgrass is a little problem that could have devastating effects.

RC Butler 2022  -  Practice Two RC Passages Everyday.   
Passage # 264 Date: 01-Jul-2022
 This question is a part of RC Butler 2022 .  Click here for Details

GREAccount · Answer

1) In paragraph 5 it's mentioned directly , straightaway answer to the question.
2)In paragraph 4 in the last sentence its mentioned as developing new sources of bioenergy.
3)a. criticize the work of an institution. passage is not about criticizing.
b. compare two possible solutions when only one is needed. No comparison.
c. provide the outcome of a finished study. Study is in progress.
d. optimistically deliver the findings of a study in progress. CORRECT
e. eliminate assumptions that are not critical to the findings. No such elimination.
4)Clearly mentioned in the paragraph 4.
5)The crux of the passage is about any alternate bioenergy source
6)the whole passage is about the switchgrass development.

hmandhan · Answer

Could someone explain how is the study in progress and not finished for Q3?

Sajjad1994 · Answer

Explanation

3. The passage’s primary function is to

Difficulty Level:   500-550

Explanation

The passage presents the findings of a study conducted by the U.S. Department of Agriculture (USDA) scientists regarding the insertion of a specific gene called corngrass into switchgrass for potential use as a biofuel crop. The information is presented in a positive and optimistic manner, emphasizing the potential benefits and implications of the research.

Key points supporting this choice:

-The passage provides information about the potential benefits of inserting the corngrass gene into switchgrass, such as keeping the plant in its juvenile form, increasing starch levels, and making sugars more readily available for conversion into cellulosic ethanol.

-The passage mentions the collaboration between USDA scientists, specifically Sarah Hake and George Chuck, highlighting the credibility of the researchers involved in the study.

-The passage discusses ongoing efforts to further enhance the research, such as introducing genetic promoters to increase root mass development and suggesting the development of nonflowering switchgrass varieties.

Overall, the tone of the passage is positive and focused on delivering the optimistic findings and potential implications of the ongoing study, supporting the choice of option d.

Answer: D

A gene that keeps switchgrass forever young could have far-reaching

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A gene that keeps switchgrass forever young could have far-reaching

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615 to 715 in 15 Days (Ria's Strategies)

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