Question 1

During a study, scientists noted that people with more self-esteem tend to not be depressed and vice versa. Which of the following types of relationships did they observe?

Accepted Answer

Correlation is a statistical measure that indicates the extent to which two or more variables change together. A positive correlation indicates that the variables are increasing or decreasing together (in parallel). A negative correlation indicates that as one variable increases the other decreases.
Spontaneous events are based on some conditions becoming true, but not based on any timing criterion.
To determine the cause of something, ask why it happened. To determine the effect of a cause, ask what happened. Cause and effect relationships show a clear connection between the "what happened" and the "why it happened."
In statistics, a random effects model is a statistical model where the model parameters are random variables.

Question 2

Dandelions ? Snail ? Frog ? Bird ? Fox
Using the food chain above, which of the following terms best describes the trophic level of frogs?

Accepted Answer

Secondary consumers are organisms that eat primary consumers for energy. Primary consumers are always herbivores, or organisms that only eat autotrophic plants. However, secondary consumers can either be carnivores (only eat meat) or omnivores (eat both meat and plants).
Plants are called producers. This is because they produce their own food. They do this by using light energy from the Sun, carbon dioxide from the air and water from the soil to produce food - in the form of glucose/sugar.

Question 3

Review the data in this table, and then choose the statement that draws the best conclusion?

Accepted Answer

Correlation is a statistical measure that indicates the extent to which two or more variables change together. A positive correlation indicates that the variables are increasing or decreasing together (in parallel). A negative correlation indicates that as one variable increases the other decreases.
In this example, time spent sleeping correlated positively with the obtained test score.
In statistics, when the value of one event, or variable, increases or decreases as a result of other events, it is said there is causation. This is not the best conclusion for our example, since, for example, people who have slept 8 and 8.2 hours have the same test score.

Question 4

Why are control groups used in experiments?

Accepted Answer

A control group is used to ensure that the number of variables that influences a data set is minimized. This is done by comparing measured data to the control group, which has many fixed variables.

Question 5

Which of the following statements is false?

Accepted Answer

The goal of a double-blind experiment is to reduce or eliminate biases from both the researcher and their subjects. This is done by keeping which treatments patients receive a secret from both the researcher and the subject. Since the patients don't know what type of treatment they received, the researcher can determine if the placebo effect affects their results.

Question 6

Which of the following is true about control variables?

Accepted Answer

Control variables are constants in an experiment that help make comparisons to other pieces of data. By having one or more control variable, the effect of other variables can be determined in an experiment.

Question 7

Which of the following statements is true?

Accepted Answer

A double-blind experiment is an experiment where both the researcher and subject are unaware of the treatment that a test subject receives. This is different from a single-blind experiment, where only the subject is unaware. Double-blind experiments help to prevent unconscious researcher bias, which means the results will be more accurate, as there is no opportunity for those running the experiment to unconsciously influence or manipulate anything to achieve the desired results.
While it is true that a double-blind experiment is used to reduce researcher bias and increase overall accuracy, this does not necessarily mean that results are always 100% accurate. This is because there can be other unknown or unaccounted variables that influence the results, called lurking variables. However, the results of double-blind experiments will always be regarded as more accurate than those achieved with a single-blind experiment.
Important note: Not all experiments can be double-blind based on the nature of the study.

Question 8

To determine if tap water was making people sick, scientists asked one group of people to drink tap water for a week and another group to drink only bottled water. The results showed that the group that drank the tap water were sick after a week. What can be concluded from this experiment?

Accepted Answer

Although it seems likely that the tap water is causing an illness of some sort, there is not enough data linking the water to the sickness. For example, there could be another environmental factor making the people sick that wasn't accounted for in the study. Additionally, the scientists did not record or control any other aspect of the patients' diets, so another factor could have caused the sickness.

Question 9

A scientist collected the following set of data to examine the effects of exercise on patients' heart rates.
 Patients were tasked with running 1 mile everyday for three days in the presence of the scientists. They were required to run the entire mile and were not allowed to walk. At the end of each mile run, the scientists measured the heart rates of the patients. Which of the following conclusions can be drawn from this data?

Accepted Answer

From the data, it is clear that the heart rate of patients after running was much higher than their resting heart rates.
There is no information provided about the pace at which the patients ran the miles.
While it is certainly possible, and even likely, that running the miles increased the patients' fitness levels, there is no data provided above to support this claim.

Question 10

Steps involved in natural selection include:
1) Differing survival rates when faced with environmental challenges.
2) Preservation of genetic traits of best-adapted offspring.
3) Overproduction of offspring that have different variations in genetic traits.
Which of the following is the sequence in which these steps take place?

Accepted Answer

Natural selection is the process by which organisms that are better suited to their environment are able to survive and produce more offspring. As a result of natural selection, the proportion of organisms within a species that have favorable adaptations to a given environment will increase with each generation.
Organisms (within populations) have differences in appearance and behavior on an individual basis. These differences, or variations, can include characteristics such as body shape or size, skin or hair color, physical markings or structures, or behaviors such as methods of obtaining food.
Organisms, within a species, that possess physical and behavioral traits that allow them to be more successful in obtaining resources will be more likely to survive and reproduce.
When organisms are faced with environmental changes, we often see a shift in what is considered a "favorable" trait within the species. This then has an effect on the overall population of organisms in terms of their physical and behavioral characteristics.
These "best adapted" traits will be passed onto the next generations given that individuals with these traits will be more likely to survive and continue reproducing.

Question 11

When studying the effects of sunlight on a person's mood, scientists asked one group of patients to remain outside for one hour and a control group to remain inside all day. At the end of the experiment, 75% of the group that had received sunlight had a better mood. What can be concluded from these results?

Accepted Answer

This is an example of a poorly-constructed experiment since it relies on self-reporting. The scientists were not present to ensure that the patients actually stayed outdoors for one hour or that the control group stayed inside all day. The scientists also did not account for other possible variables that could affect their patients' moods.

Question 12

Which is the most appropriate unit to measure the weight of groceries in a store?

Accepted Answer

While describing various physical quantities, it is best to use appropriate units of measure. Using other units of measure to describe a quantity gives either very small or very large number value. It becomes difficult to estimate the magnitude of the quantity, if inappropriate units are used.
The appropriate scale for the measurement of the weight of groceries would the kilogram. This is because the weight of most groceries is a "medium range" weight, so that it would be difficult to determine its weight while reading on a smaller scale like the micro- or nanograms. Tons are used to measure extremely heavy things, such as elephants.

Question 13

Which of the following describes a 'control variable' in an experiment?

Accepted Answer

Control variables are unchanged during an experiment so that a scientist can determine how other variables change relative to it. It is important to have control variables because they help ensure that experimental results occur because of changes in other variables.

Question 14

Which of the following correctly describes a conclusion?

Accepted Answer

A conclusion is obtained after a scientist analyzes all of his or her data after conducting an experiment. It is a statement of whether the evidence collected during the experiment supports or disagrees with the original hypothesis. Conclusions are always listed at the end of a scientific report and summarize the major findings of an experimental study.

Question 15

A well-controlled experiment was conducted where researchers noted that a new antibiotic eliminated a bacterial sinus infection. Which of the following can be inferred from this result?

Accepted Answer

The most likely explanation for the elimination of the sinus infection is that the medicine killed the bacteria. Antibiotics are drugs that kill or halt the growth of bacteria, so this is the most likely explanation for the elimination of the sinus infection since the antibiotics do not have an influence on a person's allergies or DNA.

Question 16

Which of the following is the most plausible sequence of events?

Accepted Answer

Children who are born into families that prioritize a specific activity are typically more inclined to be exposed to that activity at a young age and after years of practice, they excel at that activity.
Ozone can make it more difficult for you to breathe deeply. Airborne particles, found in haze, smoke and airborne dust, present serious air quality problems. People with asthma are at greater risk from breathing in small particles
Usually, bee stings don't cause a serious reaction. However, if you're allergic to bee stings or have had several bee stings, you may experience a severe reaction such as poisoning. Bee poisoning requires immediate medical attention.Taking an antihistamine such as diphenhydramine (Benadryl) or a nonsedating one such as loratadine (Claritin) will help with itching and swelling.
Illegal wildlife trade is also often unsustainable, harming wild populations of animals and plants and pushing endangered species toward extinction. Endangered animals and plants are often the target of wildlife crime because of their rarity and increased economic value. The bans are implemented largely through the Convention on the International Trade in Endangered Species of Fauna and Flora (CITES) and supplemented through EU and US trade measures.

Question 17

Which of the following statements is true about understanding magnitude when describing relationships?

Accepted Answer

Correlation coefficient: A measure of the magnitude and direction of the relationship (the correlation) between two variables. The closer the correlation coefficient is to +1 or -1, the stronger the relationship. The units of length in the SI system, from smallest to largest, are as follows: nanometer, millimeters, centimeter, meter, kilometer. Therefore, the centimeter is smaller than a kilometer, but the nanometer is not larger than a centimeter. The scale of a graph is what you mark on the axes. It's the relation between the units you're using, and their representation on the graph i.e., the distance between marks. An order of magnitude is a factor of ten. A quantity growing by four orders of magnitude implies it has grown by a factor of 10,000 or 10⁴.

Question 18

Based on the graph, what can you conclude about the rate of robbery, burglary and theft and unemployment rate?

Accepted Answer

Unemployment has a direct connection with growing crime rates since with deterioration of living standards, the crime rates increase. Unemployment refers to joblessness. When, in spite of the will of the people to work, they do not find it, it amounts to unemployment.
Unemployment, in varying proportions, exists everywhere around the world and has several defined repercussions on the entire socio-economic and political setup. Of these, crime is often considered to be one of the greatest repercussions.
Unemployment may lead to several factors, which may, in turn, force people to take the path of crime. For instance, unemployment may lead to social vices, such as poverty and malnutrition, which may make some people turn towards crime.
When looking through the presented data, there is a clear connection between the rate of unemployment (how many people are without  jobs) and the rate of crime. The two data sets (lines) appear to follow a similar pattern of ups and downs, which suggests a correlation between the two. Based on the data, the rate of crime increases as unemployment increases and decreases as unemployment decreases.
The other answer options presented cannot be proven by the data in the graph and are merely suppositions about people's behavior based on looking at the graph.

Question 19

A study draws the conclusion that obesity is a significant cause of Type 2 diabetes. Which of the following experimental parameters would not build confidence that such a cause and effect relationship is likely true?

Accepted Answer

When conducting an experiment, you need to specify the sample groups you will be studying. The groups need to be a practical size so that it is manageable, but you also need enough participants that would allow the results to be statistically meaningful. A small sample size may not yield results that would build confidence in the relationship between the two variables since not enough people were studied.
Other important tenets of strong experimental design include the use of controls to prevent outside factors from influencing the outcomes (data) as well as considering all of the results that are generated from the experiment.

Question 20

Based on this table, which of the following statements is true?

Accepted Answer

The following table represents the 10 leading causes of death by age group in the US for 2016. The columns represent the different age groups and the rows start with the most common cause of death, leading to the least common one.
The number of unintentional injuries among children aged 1-4 is 1,261 and for children between 5-9 years is 789 cases. Therefore the number of unintentional injuries among 1 to 4-year-old children is greater than the number of unintentional injuries among 5 to 9-year-old young children.

Exam 4: ATI-TEAS-Science