The tropical leaf-cutter, or attine, ant provides a remarkable example

Q2) Which of the following can be most reasonably inferred from the passage?

Difficulty Level: 750

Explanation

A) The fruiting bodies found on numerous fungi are a means of vegetative reproduction.

Support for A from the passage:
The ants do not allow their fungus crop to develop fruiting bodies, the means by which plants engage in sexual reproduction.

The text in red above in option A make it out of the scope of the passage.

B) Plants that rely on sexual reproduction are highly susceptible to parasitic attacks by bacteria and molds.

Support for B from the passage:
Simple parasites, such as bacteria or molds, mutate rapidly and pose a challenge to other species developing defense mechanisms.

B is nowhere mentioned as such and is out.

C)Sexual reproduction is an inefficient method for transmitting a parent’s genes to its offspring.

Support for C from the passage:
For many years, the phenomenon of sexual reproduction puzzled biologists, as it passes only half of the parent's genes to the succeeding generation and requires a more complex mechanism than does asexual reproduction.

D) The bacterium found on patches of green mold produces an antibiotic substance used by commercial mushroom farmers.

Support for D from the passage:
Escovopsis mold, a parasite related to the “green mold” known to commercial mushroom farmers, is present in the ants’ crops and poses a serious threat to the fungus. However, the attine ants provide the defense mechanism lacking in the fungus’s asexual reproduction by means of a bacterium that grows in patches on their skin.

D provides something known but in the wrong manner.

E) Parasitic bacteria use sexual reproduction as a means to achieve rapid mutation.

Simple parasites, such as bacteria or molds, mutate rapidly and pose a challenge to other species developing defense mechanisms.

Clearly, E is not mentioned. The passage didn't say that Parasitic bacteria use sexual reproduction as a means to achieve rapid mutation. This option trying to trap us with cause and effect twist.

Answer: C

Q3). The author describes the interaction between a parasite and a sexually reproducing organism as an “arms race” (Highlighted) in order to

Difficulty Level: 600

Explanation

In the passage, the author discusses how sexual reproduction allows for genetic shuffling between generations, which enables a species to evolve quickly in response to the rapid mutations of parasites such as bacteria or molds. This concept of a continuous evolution and adaptation by both the host and the parasite is analogous to an arms race, where both sides constantly develop new strategies and countermeasures to gain an advantage over the other. It emphasizes the dynamic and competitive nature of the evolutionary process.

Options A, C, and D do not accurately capture the broader concept of an ongoing evolutionary competition between two organisms, which the term "arms race" implies. Option B, regarding biological weapons, is not relevant to the context of the passage and is not mentioned in the passage.

Answer: E

Q4). The passage suggests which of the following about the fungus grown by the attine ants?

Difficulty Level: 700

Explanation

The passage mentions that the attine ants do not allow their fungus crop to develop fruiting bodies, which are the means by which plants engage in sexual reproduction. This implies that the fungus grown by the attine ants has the potential for sexual reproduction but is prevented from doing so by the ants' behavior. The passage does not provide information to support options A, B, D, or E, so they can be ruled out as less relevant to the information presented in the passage.

Answer: C

Q1). The phrase “clonal monoculture” (Highlighted) refers to which of the following?

Difficulty Level: Medium

Explanation

A clonal monoculture in this context refers to the fact that all the fungi in the attine ant gardens around the world are clones of a single source. This means that they are genetically identical and are reproducing asexually, without engaging in sexual reproduction. The ants maintain this clonal monoculture of the fungus by taking a sample of the fungus from the old nest to start a new garden when a queen ant establishes a new nest, thereby spreading the fungus vegetatively.

In the text, the concern is that a clonal monoculture, which is essentially a population of genetically identical organisms, would be highly susceptible to parasites. In this case, the fungus in the ant gardens is the clonal monoculture that is potentially at risk from parasitic attack by the Escovopsis mold. However, the ants have a defense mechanism in the form of an actinomycete bacterium that produces an antibiotic to protect the fungus from this parasite.

A) The Escovopsis mold is mentioned in the passage as a parasite that poses a serious threat to the fungus cultivated by the attine ants. This mold is not described as a "clonal monoculture" in the passage; it is a parasitic threat to the fungus. Therefore, option A is not the correct interpretation of the phrase "clonal monoculture."

B) This option is not directly related to the concept of a clonal monoculture. The text mentions that the attine ants cultivate the fungus, but it does not refer to them as a "clonal monoculture." Instead, the focus of the passage is on the fungus itself and its reproductive characteristics. Therefore, option B is not the correct interpretation of the phrase "clonal monoculture."

C) While the passage does discuss sexual reproduction as a more complex mechanism compared to asexual reproduction, it does not directly refer to it as a "clonal monoculture." The term "clonal monoculture" is used to describe the genetic makeup of the fungus, which is genetically identical and reproduces asexually. Therefore, option C is not the correct interpretation of the phrase "clonal monoculture."

D) The phrase "clonal monoculture" in the passage refers to the fungus cultivated by the attine ants. The text specifically mentions that the fungi in attine gardens around the world are clones of a single source, which means they are genetically identical and reproduce asexually. This is the correct interpretation of the phrase "clonal monoculture" in the context of the passage.

E) The antibiotic bacterium is mentioned in the passage as a defense mechanism that the attine ants use to protect their fungus from the Escovopsis mold. This bacterium is not described as a "clonal monoculture" in the passage. Therefore, option E is not the correct interpretation of the phrase "clonal monoculture."

In summary, the correct interpretation of the phrase "clonal monoculture" in the passage is option D) A fungus. It refers to the genetic makeup of the fungus cultivated by the attine ants, which is genetically identical and reproduces asexually.

Answer: D