ACT Science

SAT Question of the Day

The SAT question of the day is a Sentence Completion Question that has already been addressed on this blog: click here to see an explanation.

ACT Science Question of the Day

ACT science questions often ask you to read charts and graphs, but you do not have to understand all of the information that is provided in order to answer the question correctly.  Take a look at today's question before wading through the images.

Abandoned cornfields have been the sites of investigations concerning ecological succession, the orderly progression of changes in the plant and/or animal life of an area over time (see Figure 1).

(Note: The plants are ordered according to their appearance during ecological succession.)

During the early stages of succession, the principal community (living unit) that dominates is the pioneer community. Pioneer plants are depicted in Figure 2.

The final stage of ecological succession is characterized by the presence of the climax community, the oak-hickory forest. Figure 3 depicts the gradual change from pine to hardwoods.

Figures adapted from Eugene P. Odum, Fundamentals of Ecology. ©1971 by Saunders College Publishing/Holt, Rinehart, and Winston, Inc.

On the basis of the data depicting the gradual change from pine forest to an oak-hickory forest, after 100 years, as the density of the pine trees:

You can tell from the description of the figures that Figure 3 concerns forests, and its description even includes the words “gradual change.”  You do not need any of the other figures.  You first need to know what happens to the pine trees.  The line labeled “pine” goes down, so the pine trees are decreasing over the years.  Then notice that the line labeled “oak-hickory” goes up.  These trees are increasing during the same period.  Look down at your answer choices.

. . . as the density of the pine trees:

A. increases, the density of the oak-hickory trees increases.
B. increases, the density of the oak-hickory trees decreases.
C. decreases, the density of the oak-hickory trees increases.
D. decreases, the density of the oak-hickory trees decreases.

The correct answer is (C).


For the ACT Question of the Day, visit http://www.act.org/qotd/.To get help preparing for the SAT, PSAT, or ACT Exam, visit www.myknowsys.com!

ACT Science

SAT Question of the Day

The SAT question of the day is an Identifying Sentence Errors Question that has already been addressed on this blog: click here to see an explanation.

ACT Science Question of the Day

Science Questions on the ACT are not about memorizing facts, they are about finding information and being able to read charts.  They do not require you to know anything that is not given to you!

Passage II

    The Sun's path from sunrise to sunset varies with the time of year. A student performed the following experiments on three clear, sunny days at three- or four-month intervals throughout the course of a year to study the path of the Sun through the sky.

Experiment 1

    At a chosen Northern Hemisphere location, the student placed a stick vertically into the ground so that 1 meter of its length was left above ground. The student knew that the length of the shadow was related to the height of the Sun above the horizon and that the shadow would point away from the direction of the Sun. The length in meters (m) and direction of the shadow cast by the stick were measured one hour after sunrise (Shadow A), at mid-morning (B), at noon (C), at mid-afternoon (D), and one hour before sunset (E) on each of the three days. The direction of each shadow was determined by placing a magnetic compass at the base of the stick and aligning the north arrow with the north mark on the compass. The direction of each shadow was then determined by a comparison with the compass face markings. The results are recorded in Table 1.

Table 1
Shadow	Day 1		Day 2		Day 3
	Length (m)	Shadow  direction	Length  (m)	Shadow  direction	Length  (m)	Shadow  direction
A	5.0	SW	8.6	NW	6.8	W
B	1.2	W	2.9	NNW	1.7	NW
C	0.3	N	2.3	N	0.9	N
D	1.2	E	3.0	NNE	1.8	NE
E	5.0	SE	8.6	NE	6.9	E

Experiment 2     The following year, the student repeated Experiment 1 at a chosen location in the Southern Hemisphere. The results are in Table 2.

Table 2
Shadow	Day 1		Day 2		Day 3
	Length (m)	Shadow  direction	Length  (m)	Shadow  direction	Length  (m)	Shadow  direction
A	9.0	SW	5.0	NW	6.9	W
B	3.2	SSW	1.1	W	1.8	SW
C	2.5	S	0.3	S	1.0	S
D	3.2	SSE	1.1	E	1.8	SE
E	9.1	SE	5.0	NE	6.9	E

When the Sun is at an altitude 45° above the horizon, a vertical object will cast a shadow with a length equal to the object’s height. Which of the following days included a measurement taken when the Sun was at an altitude of 45°?

The first paragraph under Experiment 1 tells you that the stick (the vertical object) has 1 meter above the ground.  You must find a shadow length that is equal to the height in order to know that the Sun was at an altitude of 45° at that moment.  Check the charts.  There is only one shadow that is 1 meter long.  It is in the second chart (Experiment 2) under Day 3, Shadow C.  Circle it and look down at your answer choices.

A. Day 1 in Experiment 1
B. Day 1 in Experiment 2
C. Day 2 in Experiment 1
D. Day 3 in Experiment 2

The correct answer is (D).

For the ACT Question of the Day, visit http://www.act.org/qotd/.

To get help preparing for the SAT, PSAT, or ACT Exam, visit www.myknowsys.com!

ACT Science

SAT Question of the Day

The SAT question of the day is a Sentence Completion Question that has already been addressed on this blog: click here to see an explanation.

ACT Question of the Day

The ACT contains a science section that is not on the SAT.  However, you do not have to memorize science information to do well on this test!  All you have to do is be able to logically analyze and evaluate the information that you are given.  Even if you are only preparing for the SAT right now, take a look at this science question and consider whether your strengths are suited to the ACT.

Note:  ACT science passages throw a lot of information at you.  It is best to ignore the details in the charts until you know what information the question asks you to find.

Passage II

    The Sun's path from sunrise to sunset varies with the time of year. A student performed the following experiments on three clear, sunny days at three- or four-month intervals throughout the course of a year to study the path of the Sun through the sky.

Experiment 1

    At a chosen Northern Hemisphere location, the student placed a stick vertically into the ground so that 1 meter of its length was left above ground. The student knew that the length of the shadow was related to the height of the Sun above the horizon and that the shadow would point away from the direction of the Sun. The length in meters (m) and direction of the shadow cast by the stick were measured one hour after sunrise (Shadow A), at mid-morning (B), at noon (C), at mid-afternoon (D), and one hour before sunset (E) on each of the three days. The direction of each shadow was determined by placing a magnetic compass at the base of the stick and aligning the north arrow with the north mark on the compass. The direction of each shadow was then determined by a comparison with the compass face markings. The results are recorded in Table 1.

Table 1
Shadow	Day 1		Day 2		Day 3
	Length (m)	Shadow  direction	Length  (m)	Shadow  direction	Length  (m)	Shadow  direction
A	5.0	SW	8.6	NW	6.8	W
B	1.2	W	2.9	NNW	1.7	NW
C	0.3	N	2.3	N	0.9	N
D	1.2	E	3.0	NNE	1.8	NE
E	5.0	SE	8.6	NE	6.9	E

Experiment 2     The following year, the student repeated Experiment 1 at a chosen location in the Southern Hemisphere. The results are in Table 2.

Table 2
Shadow	Day 1		Day 2		Day 3
	Length (m)	Shadow  direction	Length  (m)	Shadow  direction	Length  (m)	Shadow  direction
A	9.0	SW	5.0	NW	6.9	W
B	3.2	SSW	1.1	W	1.8	SW
C	2.5	S	0.3	S	1.0	S
D	3.2	SSE	1.1	E	1.8	SE
E	9.1	SE	5.0	NE	6.9	E

If the experiments were repeated after pounding the stick farther into the ground so that only 0.5 m was exposed, how would this affect the shadow lengths?

You are given a lot of information that you do not need to know to answer this question.  The passage tells you that the original stick had one meter exposed above the ground.  If you pound it in until .5 meters are exposed, you have taken half of the stick away.  Smaller things logically must make smaller shadows (think of a bug and a building at the same time of day), so look down at your answer choices.

A. They would be twice as long as those in the original experiments.
B. They would be one-and-one-half times as long as those in the original experiments.
C. They would be one-half as long as those in the original experiments.
D. They would be one-fourth as long as those in the original experiments.

(A)  The shadows would only get larger if more of the stick were exposed.  Eliminate this choice.

(B)  The shadows would only get larger if more of the stick were exposed.  Eliminate this choice.

(C)  This answer makes sense because if half of the original stick is showing, it must have half the shadow of the original stick as well.

(D)  Even if you carefully analyze all of the numbers in the chart, there are no important numbers that have a relationship of one-fourth.  Eliminate this choice.

The correct answer is (C).

Sentence Completions

Link of the Day

We once thought that sending a man to the moon was impossible. Well, NASA has done the impossible again. The Curiosity space rover, a mobile lab the size of a small car and weighing around a ton, landed safely on the surface of Mars last night after a completely autonomous seven-minute landing sequence. Because of the size and weight of the rover, NASA had to invent an entirely new process to get Curiosity to the planet's surface. The sequence involved an "automated flight-entry system," a supersonic parachute, and a giant jetpack NASA calls a "sky crane." Most impressive of all, the entire landing was accomplished without the help or input of any humans. There is a 14-minute communications delay between Earth and Mars, so it would be impossible to respond to any problems in time, and on top of that the Earth disappeared below the Martian horizon two minutes before Curiosity touched down. Read more about the landing here and about the mission here. 

8/5 Sentence Completions

Choose the word or set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole.

Sentence completion questions test your vocabulary and your ability to think logically.  Never look at the vocabulary in the answer choices until you have read the entire sentence carefully and predicted an answer choice for a blank.  If there are two blanks, focus on the easy blank and eliminate any choices that do not match your prediction for that blank.  Then return to the other blank, make a prediction for that blank and eliminate any remaining choices that do not fit with your prediction.

It was difficult to believe that the sophisticated piece of technology had ------- through the centuries from such ------- and rudimentary apparatus.

It is easy to fill in the blanks for this sentence if you understand all of the vocabulary.  However, even if you are unsure of a definition (or several), you can still use the Knowsys method to come up with a prediction.  Look at the first blank.  Paraphrase the sentence using the terms you know: “I can’t believe that technology like this came from something like that.”  The key to predicting the first blank is to find out what happened to technology over time.  It clearly changed from one description to another, but try to make your prediction a little more specific.  “Sophisticated” is a positive word, so it is safe to assume that technology improved over time.  Use the word “improved” as your prediction and look down at the first part of your answer choices. 

(A) developed . . an intricate

(B) resulted . . a complicated

(C) evolved . . a quaint

(D) degenerated . . an obsolescent

(E) differed . . an exotic

(A) matches.  (B) is a little awkward, but you can keep it in mind. (C) matches – “evolved” and “developed” can be synonyms. (D) can be eliminated because “degeneration” is a negative word; technology did not get worse over time.  (E) can be eliminated because “differed” is a neutral word for change and you are looking for a positive one.  Three answer choices remain, so look at the second blank. 

You know that something new came from something older and simpler.  The “simpler” part of this prediction is clearer if you know the definition of “rudimentary,” but you can eliminate all the wrong answer choices just by predicting the word “old.”  Look at the second answer choices now for the letters you have not yet eliminated.

(A) developed . . an intricate

(B) resulted . . a complicated

(C) evolved . . a quaint

(A) And (B) can be eliminated because “intricate” and “complicated” do not mean “old” and they are the opposite of “simple.”

The correct answer choice is (C).

Words tested in this SC:

Sophisticated: refined

Rudimentary: basic

Apparatus: a machine or tool

Intricate: complex

Quaint: having old-fashioned charm

Degenerated: degraded, having deteriorated

Obsolescent: becoming obsolete or antiquated

Exotic: foreign, non-native (*this is the second time in three days that this word appears in a question!)

On sat.collegeboard.org, 71% of responses were correct.

For more help with vocab, visit www.myknowsys.com!

Sentence Completions

Link of the day

Did you know that jellyfish are actually a kind of plankton? Their movements and gelatinous bodies make them seem complex but they are actually very simple creatures. They have no bones, brains, or heart and they are mostly water (98%). You can learn more about jellyfish here.

6/18 Sentence Completions

Choose the word or set of words that, when inserted into the sentence, best fits the meaning of the sentence as a whole.

Always start out by reading the sentence carefully and making a prediction for the blank. Four of the five answer choices are wrong, so looking at the answer choices without making a prediction will only hurt you. Read the sentence carefully and look for clues to help you predict a word for the blank. Then, look at the answer choices and choose the word that matches your prediction.

The jellyfish's slow pulsing action propels it in a graceful, seemingly _________ drift, but it's tentacles contain a poison potent enough to stun a swimming human.

Parallelism

Link of the Day

Elevators have been in use since the 3rd century B.C. However, it wasn't until the mid 1800's that elevators came into common use. Before then they had been used mainly in industrial settings for moving materials. In 1853 though, Elisha Otis invented a safety brake system that would stop an elevator from falling if the support cables broke. His braking system is still used today. You can read more about the history of elevators here.

6/10 Identifying Sentence Errors

The following sentence contains either a single error or no error at all. If the sentence contains an error, select the one underlined part that must be changed to make the sentence correct. If the sentence contains no error, select choice E. 

AThe introduction of elevators in hotels meant that Bpreviously undesirable rooms on the top floors, Caway from the bustle and noise of the street, became sought after and more expensive than Dthe lower floors. ENo error

Always read the sentence first to get a general feel for how it sounds. If something seems strange or wrong, start with the part of the sentence that caught your attention. Check that segment against what you know of standard English grammar. If nothing stands out to you, check all four underlined sections. When you find one that breaks the rules, mark it.

Does anything sound odd? If not, don't worry, just check each answer choice individually. You may notice that the sentence seems fairly long and complicated. That's a good sign that the test makers are trying to hide something and trick you. Remember that often the underlined portion will look alright on it own if you don't take the whole sentence into account.

(A) doesn't really have anything wrong with it. It is worth noting that the subject of our sentence is "The introduction of elevators" though. You can now check for subject verb agreement (in this case there is no subject verb agreement error).

(B) is also error free. "Previously" is an adverb modifying "undesirable" (which is an adjective modifying "rooms"). Both words are being used properly.

(C) may seem strange at first. Note that "away from the bustle of the noise of the street" is in-between two commas because it is a non-restrictive element. Even though it may look a little out of the ordinary, there is no error here either.

(D) seems to be fine as well however, you should notice that it is part of a comparison (because it is preceded by the word "than"). If you look back in the sentence to see what "the lower floors" are being compared to, you will see that the sentence is comparing "undesirable rooms on the top floors . . . " to ". . . the lower floors." Since that comparison doesn't make sense, (D) is the error.

The correct answer choice is (D).

On sat.collegeboard.com 34% of the responses were correct.

For more help with grammar, visit www.myknowsys.com!

Subject Verb Agreement

Link of the Day

Sharks are some of nature's most magnificent predators. They have no bones (only cartilage) and their streamlined bodies allow them to glide through the water at incredible speeds. While sharks have a sinister reputation, in reality they rarely attack people. You can learn more about sharks here.

6/4 Identifying Sentence Errors

The following sentence contains either a single error or no error at all. If the sentence contains an error, select the one underlined part that must be changed to make the sentence correct. If the sentence contains no error, select choice E. 

For Identifying Sentence Errors questions, always read the sentence and focus on anything that sounds strange or wrong. Determine whether that part of the sentence is actually incorrect, then identify the part of the sentence that, if changed, would correct the error. Double-check that the other sections of the sentence are correct as they are and, finally, mark the correct answer on your answer sheet.

AMost of the world’s Bsharks, living in temperate and tropical regions, Cthough the Greenland shark lives in the cold Arctic waters, and the huge basking shark is at home in the seas Daround Antarctica. ENo error