ACT Science : Biology

Study concepts, example questions & explanations for ACT Science

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Example Questions

Example Question #61 : Biology

The graph below indicates the numbers of three different kinds of rare beetles that were found in a section of forest over a period of years.

Actsqb1

Which of the following accurately describes the situation in 1965?

Possible Answers:

All three plants had equal densities.

Lucanidae had the highest density.

The population of two plants was dwindling, while one was expanding.

The density of Staphylinidae was rapidly increasing.

Correct answer:

The population of two plants was dwindling, while one was expanding.

Explanation:

The population of Lucanidae was increasing while the other two were decreasing.

Example Question #62 : How To Find Data Representation In Biology

The graph below indicates the numbers of three different kinds of rare beetles that were found in a section of forest over a period of years.

Actsqb1

Which species were present in approximately equal numbers in 1955?

Possible Answers:

Staphylinidae and Lucanidae

StaphylinidaeLucanidae, and Scarabaeidae

 Staphylinidae and Scarabaeidae 

Lucanidae and Scarabaeidae

Correct answer:

 Staphylinidae and Scarabaeidae 

Explanation:

Around 1955, Staphylinidae and Scarabaeidae exhibit a frequency of around 200.

Example Question #63 : How To Find Data Representation In Biology

The graph below indicates the numbers of three different kinds of rare beetles that were found in a section of forest over a period of years.

Actsqb1

Which species had the highest density in 1970?

Possible Answers:

Staphylinidae

Lucanidae

All three species had equal densities in 1970.

Scarabaeidae

Correct answer:

Lucanidae

Explanation:

Considering the region halfway between 1965 and 1975, Lucanidae had by far the highest density.

Example Question #64 : How To Find Data Representation In Biology

The graph below indicates the numbers of three different kinds of rare beetles that were found in a section of forest over a period of years.

Actsqb1

Which of the following years was the most favorable for growth for Scarabaeidae?

Possible Answers:

1978

1940

1958

1934

Correct answer:

1978

Explanation:

1978 is the only year listed in which the density of Scarabaeidae increased.

Example Question #65 : How To Find Data Representation In Biology

The graph below indicates the numbers of three different kinds of rare beetles that were found in a section of forest over a period of years.

Actsqb1

In which of the following years did Staphylinidae have the highest density?

Possible Answers:

1940

1930

1970

1960

Correct answer:

1960

Explanation:

In 1960 Staphylinidae has the highest density.

Example Question #61 : Biology

The graph below indicates the numbers of three different kinds of rare beetles that were found in a section of forest over a period of years.

Actsqb1

Which of the following is a possible scenario that during the 1930s to 1950?

Possible Answers:

A wildfire decimated much of the environment that the beetles need to survive.

Competition between the three species lead to a precipitous population decline.

A dramatic increase in the food supply of the beetles occured, leading to population growth.

A specific predator that preys on one species created opportunity for growth for the other two.

Correct answer:

A specific predator that preys on one species created opportunity for growth for the other two.

Explanation:

During the 1930s to around 1950, the density of Scarabaeidae fell, allowing the other species to prosper in the following decades.

Example Question #61 : How To Find Data Representation In Biology

Vaccinations have become a controversial topic in the United States. Currently the US Food and Drug Administration (FDA) regulates all vaccines. The federal government does not mandate vaccinations for any individual; however, all states require vaccinations for children entering public school. There are several types of vaccines—live attenuated vaccines, inactivated vaccines, subunit vaccines, toxoid vaccines, and conjugate vaccines, just to name a few. All of these vaccines have the shared purpose of exposing the host body to antigens of a specific disease. When the body receives the antigens, the immune system is activated, remembering the antigens. The next time the individual is exposed to the disease, the body will remember the antigen and have a better probability of not getting infected. Two scientists below discuss their belief on vaccines.

Scientist 1

Vaccines have saved many lives. The risks of not being vaccinated far outweigh the risks of adverse vaccine reactions. Reports linking autism to vaccines have been evaluated by the CDC, which states there is no scientific link between autism and vaccines. The second leading cancer killer in women is cervical cancer. The HPV vaccine protects against the two most common strains causing cancer. This is an example of a vaccine that does much more good than bad. Vaccines also reduce the amount of money spent on healthcare, because the preventative cost of a vaccine is much cheaper than the cost of treating an infected person. The only time a vaccine should not be administered is if the chance of the individual coming into contact with the disease is so rare it is not worth the potential of adverse reactions.

 Scientist 2

Many vaccines nowadays are extraneous. Vaccines for diseases like whooping cough and scarlet fever were once necessary but now outdated. Modern updates on hygiene, waste management, and water filtration have resulted in significantly decreased chances of infection. In addition, diseases like rotavirus have an infection period of a few days, and the main symptom is dehydration. Modern medicine can easily treat severe dehydration, and the risk of rotavirus infection is very slim; therefore, the results of infection are far milder than the results of an adverse reaction. Vaccines for children can cause extremely dangerous adverse reactions. This includes anaphylactic shock, paralysis, and death. While scientists have not been able to conclusively prove this, many believe that these reactions are related to the age of the host and the lack of a developed immune systemor neural network. Vaccines suppress the immune system, which can lead to autoimmune disorders. In addition, vaccines can congest the lymphatic system with proteins molecules from the vaccines; therefore, I would recommend requirements for vaccination to take place at a later stage in a child’s development.

Both scientists would be most likely to agree with which of the following statements?

Possible Answers:

Vaccines should not be administered when the possible adverse reactions are not worth the protection, such as a very uncommon, but mild, disease. 

Vaccines also reduce the amount of money spent on healthcare, because the preventative cost of a vaccine is much cheaper than the cost of treating an infected person. 

Vaccines suppress the immune system, which can lead to autoimmune disorders. 

None of the choices listed. 

Vaccines for diseases like whooping cough and scarlet fever were once necessary but now outdated.

Correct answer:

Vaccines should not be administered when the possible adverse reactions are not worth the protection, such as a very uncommon, but mild, disease. 

Explanation:

Scientist 1 states that "the only time a vaccine should not be administered is if the chances of the individual coming into contact with the disease are so rare it is not worth the potential of adverse reactions." Scientist 2 states that "the results of infection are far milder than the results of an adverse reaction" while discussing rotavirus as part of his argument that vaccines should not be administered.

Example Question #62 : How To Find Data Representation In Biology

An experiment was done to test the antibiotic resistance of the bacteria Pseudomonas flourescens and Escherichia coli by using the antibiotic disk sensitivity method. Four different antibiotics were tested on each bacterium. Media were prepared with each type of bacterium and a drop of each antibiotic was added to each corner of the plates, a different antibiotic in each corner. The cultures were observed for eighteen hours. After this period of time, the zones of inhibition (where the bacteria was not able to grow due to the antibiotic) were measured. The table below shows the results of the four antibiotics on the two bacteria, Pseudomonas flourescens and Escherichia coli.

 

 

Antibiotic 1

Antibiotic 2

Antibiotic 3

Antibiotic 4

Pseudomonas flourescens

11mm

2mm

5mm

20mm

Escherichia coli

 

10mm

8mm

3mm

10mm

Which antibiotic was the most effective? 

Possible Answers:

Antibiotic 4

Antibiotic 1

They were all equally effective

Antibiotic 3

Antibiotic 2

Correct answer:

Antibiotic 4

Explanation:

Antibiotic 4 was the most effective because it resulted in the greatest average zone of inhibition. The passage states that the zone of inhibition is the region where bacteria are unable to grow. The purpose of an antibiotic is to kill bacteria, preventing growth; thus, the larger the zone of inhibition, the more effective the antibiotic is at killing the bacteria.

Example Question #66 : Act Science

An experiment was done to test the antibiotic resistance of the bacteria Pseudomonas flourescens and Escherichia coli by using the antibiotic disk sensitivity method. Four different antibiotics were tested on each bacterium. Media were prepared with each type of bacterium and a drop of each antibiotic was added to each corner of the plates, a different antibiotic in each corner. The cultures were observed for eighteen hours. After this period of time, the zones of inhibition (where the bacteria was not able to grow due to the antibiotic) were measured. The table below shows the results of the four antibiotics on the two bacteria, Pseudomonas flourescens and Escherichia coli.

 

 

Antibiotic 1

Antibiotic 2

Antibiotic 3

Antibiotic 4

Pseudomonas flourescens

11mm

2mm

5mm

20mm

Escherichia coli

 

10mm

8mm

3mm

10mm

 

Which combination shows the strongest antibiotic resistance?  

Possible Answers:

Pseudomonas flourescens and Antibiotic 2

Pseudomonas flourescens and Antibiotic 4

Pseudomonas flourescens and Antibiotic 1

Escherichia coli and Antibiotic 3

Escherichia coli and Antibiotic 1

Correct answer:

Pseudomonas flourescens and Antibiotic 2

Explanation:

The passage says that the zone of inhibition is the region where bacteria cannot grow. The bacteria showing the greatest antibiotic resistance would have the smallest zone of inhibition. If a bacteria has resistance to an antibiotic, the antibiotic will not be effective at killing the bacteria and creating a zone of inhibition. Pseudomonas flourescens grown with Antibiotic 2 has the smallest zone of inhibition: 2mm.

Example Question #61 : Act Science

Scientists studied a species of termite and looked at their foraging habitats across the United States. The termite’s population in a given tree was measured by the level of decomposition within a tree, due to the termites eating the bark. The experiment also kept track of the level of shade tolerance for each species of tree. For the species of trees in this experiment, shade tolerance fell into two main categorizes- shade tolerant (ST) and intermediate shade (IS). Lastly, they recorded the average amount of rainfall in that given month for the species location being observed. The chart below summarizes the data. Scientists hypothesized that the level of decomposition would be highest in tree species with a higher average rainfall. In addition, they hypothesized that the trees allowing more shade would allow for more termites and, in turn, more decomposition. 

 

 

Tsuga canadensis

Morus rubra

Pinus

strobus

Acer rubrum

Arbutus

menziesii

Quercus

lobata

Juniperus

scopulorum

Decomposition

(in ccm)

2.38

3.21

1.01

.970

2.89

1.31

4.03

Shade tolerance

ST

ST

IS

IS

ST

IS

ST

Average rainfall

47.27

50.89

43.26

41.65

46.87

44.98

52.75

The relationship between average rainfall and the quantity of termites in a certain tree species is that __________

Possible Answers:

lower rates of rainfall accompany greater quantites of termites. 

higher rates of rainfall accompany lower quantites of termites. 

None of the answer choices listed

quantites of termites stay the same regardless of rainfall rates. 

higher rates of rainfall accompany greater quantites of termites. 

Correct answer:

higher rates of rainfall accompany greater quantites of termites. 

Explanation:

The tree species with the highest average rainfall (Morus rubra, Juniperus scopulorum, and Tsuga canadensis) have the highest level of decomposition (3.21, 4.03, and 2.38.) Remember that the experiment uses the level of decomposition as a rough estimation of termite population. 

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