Insects and drugs - RC Passage

[me.parashar]

Hi,
Here's a passage from MGMAT CAT1. I have a clarification on question no. 2 of this passage:

Dogs are widely used by the police as biological recognition systems to detect drug smuggling and drug caches. Yet recent evidence suggests that insects, rather than mammals, might be used more effectively in this capacity. In the 1950s, German biologist Dietrich Schneider developed the first method that enabled researchers to record activity in insect olfactory nerves and to identify the compounds or class of compounds that trigger a particular behavioral response. The position of the insect olfactory organs on the surface of its body allows for direct investigation of the system’s response. Schneider’s technique formed the foundation of an olfactory detection system based upon insects, a system that is at least as effective as the ones based upon mammals.
Insects have olfactory systems that are very similar to those of vertebrates. Insects first detect odors via finger-like protuberances on the antenna, called olfactory sensilla. The odorant molecules pass through pores in the outer cuticle of the sensilla and become attached to an odorant-binding protein. This protein carries the hydrophobic molecules through the lymph fluid found inside the cell and attaches them to receptors on the dendritic projections of a sensory nerve cell. Finally, these receptors send signals to the central nervous system, allowing researchers to detect and interpret the responses.

Which of the following statements can be most reasonably inferred from the passage?
1) Some police departments have already tested using insects to detect smuggling.
2) The use of dogs to detect smuggling dates back to the nineteenth century.
3) Detection of signals sent by the receptors to the central nervous system is easier in insects than in mammals.
4) In the first half of the twentieth century, there was no reliable method for recording the activity in insect olfactory nerves and identifying the compounds that trigger a behavioral response.
5) The position of the insect olfactory organs on its body varies between flying insects and crawling insects.

Can you please tell me why 4) is right? As I see it, 1950 also comes in first half of the 20th century. So if Dietrich Schneider did develop the reliable method in 1950, that means someone who's stating any facts about the incidence in 2013 will say that the reliable method was developed in the first half of the 20th Century.

Please advise where my reasoning is going wrong. Thanks.

[jnelson0612]

Can you please tell me why 4) is right? As I see it, 1950 also comes in first half of the 20th century. So if Dietrich Schneider did develop the reliable method in 1950, that means someone who's stating any facts about the incidence in 2013 will say that the reliable method was developed in the first half of the 20th Century.

Please advise where my reasoning is going wrong. Thanks.

Actually, the GMAT will say that 1950 is the first year of the second half of the 20th century. Let me explain:

A century has 100 years. The 20th century ranged from 1900 to 1999.
1900 to 1949 is 50 years (1900 is 1 year and 1901 to 1949 is 49 years).
1950 to 1999 is 50 years (1950 is 1 year and 1951 to 1999 is 49 years).

So 1950 is technically in the second half of the 20th century. It is the first year of the second half of the 20th century. :-)

[JacobW468]

Hi, I have a question on the same passage. It is the general purpose type question.

Which of the following most accurately describes the primary purpose of the passage?

(a) To urge that one animal be used in place of another to perform a certain job

(b) To explain the advantages and disadvantages of a biological mechanism

(c) To describe a biological mechanism and indicate how it might be exploited

(d) To demonstrate the method by which a type of animal gathers sensory information

(e) To summarize the history of a particular researcher’s contributions

I reviewed this question, and got the answer wrong twice (picking D, both times). Can you explain further how, even though the whole second paragraph goes into detail on the method, the better answer, or more complete answer, is C? Especially since the phrase, "indicated how it might be exploited" seemed strong (word exploited here is substituted for "used" I suppose, but still the answer didn't jump out to me).

[JacobW468]

Same passage guys, I'm really doubling down here. Here's the question below:

It can be inferred from the passage that insects would be less useful for helping researchers to detect drugs if which of the following were true?

(a) They were as accurate as, but not more accurate than, dogs in detecting drugs.

(b) Insect olfactory systems did not deliver odorants to nerve cells in the same way as vertebrate olfactory systems do.

(c) Dietrich Schneider did not develop the first method that enabled researchers to record the activity in insect olfactory nerves.

(d) They did not have finger-like protuberances for detecting odors.

(e) The signal sent to the insect’s central nervous system did not allow researchers to classify the compound that triggered the response.

This one seems subtle to me. I am stuck between answers B & E. I read the explanation, but it seems like E is more direct with "...did not allow researchers to..." and maybe that's the trigger to recognize it is the answer. However, B looks good because the first paragraph states that it is like those of vertebrates, if it weren't could you argue that it'd be "less useful"?

[zedoul485]

I also have a question on this one.

Which of the following statements can be most reasonably inferred from the passage above?
A. Some police departments have already tested using insects to detect smuggling.
B. The use of dogs to detect smuggling dates back to the nineteenth century.
C. Detection of signals sent by the receptors to the central nervous system is easier in insects than in mammals.
D. In the first half of the twentieth century, there was no reliable method for recording the activity in insect olfactory nerves and identifying the compounds that
trigger a behavioral response.
E. The position of the insect olfactory organs on its body varies between flying insects and crawling insects.

On the first paragraph of the passage, it said "Yet recent evidence suggests that insects, rather than mammals, might be used more effectively in this capacity." and based on the final sentence of the passage, "research are able to record the respond time" isn't it mean that "Detection of signals sent by the receptors to the central nervous system is easier in insects than in mammals." ??

[RonPurewal]

the word "easier" isn't justified, because, according to the passage, the systems work in pretty much the same way.

to figure out what the advantage is, you need to use a bit of common sense -- basically, the advantage is that it's a whole lot easier (and cheaper!), in practical terms, to breed insects than mammals.

__

[RonPurewal]

MUCH MORE IMPORTANTLY -- don't forget HOW THE DETAIL QUESTIONS WORK in RC!

you will basically NEVER have to do anything beyond just
• finding relevant information,
and
• finding an answer choice that SAYS ONE OF THE SAME THINGS, in DIFFERENT WORDS.

like
——passage says "my brother is taller than me"
——answer says "i'm shorter than my brother"

really, it's that simple. (the primary skill set / challenge here is narrowing the search and finding the relevant information. once you've done that, you will NOT have to face ANOTHER significant skill challenge.)

__

note how this question works:

passage says "bla bla bla first happened in the '50's"

answer says "bla bla bla wasn't possible before 1950"

same relationship.