Biologists have advanced two theories to explain why schooling of fish

Hello ,

Yes the answers are straight forward but can some one help me in understanding the flow for theory A in the passage.

Proponents of theory A dispute the assumption that a school of thousands of fish is highly visible. Experiments have shown that any fish can be seen, even in very clear water, only within a sphere of 200 meters in diameter. When fish are in a compact group, the spheres of visibility overlap. Thus the chance of a predator finding the school is only slightly greater than the chance of the predator finding a single fish swimming alone.

People in favor of theory A first dispute that School is highly visible and then they conclude that chance predator finding the school is slightly greater than finding individual fish.
To me the two statements seems to oppose rather than support .

Where am I going wrong ?

Main idea:

Author is trying to provide two theories why schooling occurs among fishes. author gave two theories, which are about protection from predetors.

Tone: author is not biased and just gave two theories.

A)Theory B stats that how movement of different fish can save them.
B)This can be answered from main idea
C)Predators only go after distinct prey. fish take advantage of this revolve around to confuse them.
D)Go with the tone of the passage.

4. The author is primarily concerned with
(A) discussing different theories--yes theory A and B
(B) analyzing different techniques--only one technique is mentioned that is "schooling"
(C) defending two hypotheses--author is not defending anything
(D) refuting established beliefs--he is not refuting any belief
(E) revealing new evidence---no new evidence is outlined rather exisiting theory is discussed..

Hope it helped....

Q4. The author is primarily concerned with
A. discussing different theories
B. analyzing different techniques
C. defending two hypotheses
D. refuting established beliefs
E. revealing new evidence

Why is A correct?
The author only discussed 2 theories. I got confused and marked C.

Hi Shivangi24,

True, the author discusses only two theories, but he is discussing different theories right. Author is not defending anything, he is simply explaining how each theory attempts to explain why schooling of fish occurs in so many fish species. Thus making A the correct choice.

Hope This Helps.
Thanks.

Hi abhinav008 the keyword here is only, proponents of theory A dispute the claim that schools are highly visible, they go on to defend their position and mentions that schools are not highly detectable but only slightly more detectable than a single fish.

I hope that helps

RC#7 Long Passage {8 mins 4/4 correct}

Pharaphasing
Para 1: Advanced two theories to explain schooling of fish.
Para 2: Theory A
- Formation of compact group
- The chance of a predator finding the school is only slightly greater unless fish were dispersed throughout an area
Para 3: Critics of theory A
- School continues to be of value to its members even after detection.
Para 4: The "confusion effect" two different way
- Predators cannot decide which fish to attack first
- Sensory confusion caused by a large number of preys moving around the predator
- the movement of other prey in the school can be distracting

1. According to the passage,
theory B states that which of the following is a factor that enables a schooling fish to escape predators?
(A) The tendency of fish to form compact groups
Wrong: as mentioned in passage in para 2 “Experiments have shown that any fish can be seen, even in very clear water, only within a sphere of 200 meters in diameter. When fish are in a compact group” refers to theory-A

(B) The movement of other fish within the school
Correct: as mentioned in Passage Para 4 about “sensory confusion” – “Even if the predator makes the decision to attack a particular fish, the movement of other prey in the school can be distracting”

(C) The inability of predators to detect schools
Wrong: as mentioned in passage 2 “a predator's chance of finding any particular fish swimming in the school is much smaller than its chance of finding at least one of the same group of fish” refer to theory A

(D) The ability of fish to hide behind one another in a school
Wrong: Not mentioned in both the theory

(E) The great speed with which a school can disperse
Wrong: Not mentioned in both the theory


2. According to the passage, both theory A and theory B have been developed to explain how
(A) fish hide from predators by forming schools
Wrong: its not about hiding from predators, its is about protection from predators by confusing, illusion of making appear big than predators

(B) forming schools’ functions to protect fish from predators
Correct: as mentioned in passage para 1 last line “both theories assume that schooling offers the advantage of some protection from predators“

(C) schooling among fish differs from other protective behaviors
Wrong: differ from other protective behaviors not mentioned, only one is mentioned to protect from predator

(D) small fish are able to make rapid decisions
Wrong: Easy elimination, this is not mentioned in passage

(E) small fish are able to survive in an environment densely populated by large predators
Wrong: No, the passage refer only discussion about the protection from predators, large and small variations not mentioned in the passage.


3. According to one explanation of the "confusion effect," a fish that swims in a school will have greater advantages for survival if it

(A) tends to be visible for no more than 200 meters
Wrong: this is in refers of theory A

(B) stays near either the front or the rear of a school
Wrong: it has to a part of school, either the front or the rear, makes no importance.

(C) is part of a small school rather than a large school
Wrong: Small school and large school advantages & disadvantages not mentioned in the passage

(D) is very similar in appearance to the other fish in the school
Correct: as mentioned in the passage in para 4 “In many schools the fish are almost identical in appearance, making it difficult for a predator to select one.”

(E) is medium-sized
Wrong: Easy elimination, Not mentioned in the passage.


4. The author is primarily concerned with
(A) discussing different theories
Correct: passage mentioned theory A and theory B, and there some views from Proponents and critics

(B) analysing different techniques
Wrong: there is no detailed examination of the techniques or structure of something

(C) defending two hypotheses
Wrong: No defending of any supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation

(D) refuting established beliefs
Wrong: There is no negative or counter argument mentioned in the passage to be disprove

(E) revealing new evidence
Wrong: Passage brief only about two theory, no new evidence mentioned in the passage

2 theories why schooling occurs--both assume protection from predators
Theory A--predator's chance of finding a fish in school<finding one if dispersed
Theory B--"Confusion effect"- 2 explanations
---1) pred cannot decide
---2) sensory confusion

Yippie! First RC ever, where all answers are correct.
7 Minutes...

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