TEAS Science Practice Test #3 — Questions and Answers

Question 1: A scientist found that when an invasive species was introduced into a river, the population of salmon native to the region decreased. The type of correlation between these two populations could best be described as

a direct relationship.
an inverse relationship. (Correct answer)
a direct and indirect relationship.
no decisive relationship.

Correct answer: an inverse relationship.

An inverse relationship (also known as a negative correlation) describes a situation where two variables move in opposite directions. In this case, the introduction and likely increase of an invasive species led to a decrease in the native salmon population. This indicates that as one population increased, the other declined, demonstrating an inverse correlation between their numbers.

Question 2: The addition of a catalyst to a chemical reaction will have what effect?

Increase the energy required for the reaction to take place.
Increase the time required for the reaction to take place.
Increase the rate at which the reaction takes place. (Correct answer)
Reduce the amount of products in the reaction.

Correct answer: Increase the rate at which the reaction takes place.

A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It achieves this by providing an alternative reaction pathway that has a lower activation energy. By lowering the energy barrier, more reactant molecules can overcome it and form products more quickly, thereby accelerating the overall reaction rate.

Question 3: The pharynx is part of what body system?

respiratory (Correct answer)
muscular
lymphatic
circulatory

Correct answer: respiratory

The pharynx is a muscular tube located behind the nose and mouth, connecting them to the esophagus and larynx. It serves as a common passageway for both air and food. Its primary role in conducting air to the larynx and lungs makes it an integral part of the respiratory system.

Question 4: Which of the following is true about eukaryotic cells?

They do not contain lysosomes.
They contain one chromosome.
They contain one chromosome.
They contain mitochondria. (Correct answer)

Correct answer: They contain mitochondria.

Eukaryotic cells are characterized by the presence of membrane-bound organelles, which include mitochondria. Mitochondria are crucial for cellular respiration, the process that generates ATP (energy) for the cell. This organelle is a defining feature that distinguishes eukaryotic cells from prokaryotic cells.

Question 5: What characteristic of an element determines its specific isotope?

Number of protons.
Number of neutrons. (Correct answer)
Number of electrons.
Number of quarks.

Correct answer: Number of neutrons.

The atomic number, which is determined by the number of protons, defines an element's identity. Isotopes of an element have the same number of protons but differ in their number of neutrons. Therefore, the number of neutrons determines the specific isotope of an element, affecting its atomic mass but not its chemical properties.

Question 6: What is NOT true about RNA?

It contains a sugar called ribose.
Thymine is not one of its base pairings.
It is unstable in alkaline conditions.
Its sugar is more reduced than DNA’s sugar. (Correct answer)

Correct answer: Its sugar is more reduced than DNA’s sugar.

RNA contains ribose sugar, which has a hydroxyl group (-OH) on its 2' carbon. In contrast, DNA contains deoxyribose sugar, which lacks this hydroxyl group, making it more reduced (fewer oxygen atoms) and chemically more stable than ribose. Therefore, stating RNA's sugar is more reduced than DNA's sugar is incorrect.

Question 7: Which of the following scenarios would NOT give a normal distribution?

A distribution of the yearly income of families in the U.S.
The distribution of heights in a large sample of people.
The percentage of toxic wastes and pollution in the atmosphere vs. the lifespan of organisms in the location. (Correct answer)
A curve with 97% of the population within the first two standard deviations.

Correct answer: The percentage of toxic wastes and pollution in the atmosphere vs. the lifespan of organisms in the location.

A normal distribution is a symmetrical, bell-shaped curve often observed in natural phenomena like heights or test scores. The relationship between toxic wastes/pollution and lifespan is unlikely to be symmetrical; increased toxins would generally lead to a skewed distribution with decreased lifespans, not a bell-shaped curve around a mean. This complex relationship would not typically fit the characteristics of a normal distribution.

Question 8: In a cell, the Golgi apparatus is found in what location?

Inside the nucleus
Inside the mitochondria
In the cell wall
In the cytoplasm (Correct answer)

Correct answer: In the cytoplasm

The Golgi apparatus is a membrane-bound organelle responsible for modifying, sorting, and packaging proteins and lipids for secretion or delivery to other organelles. In eukaryotic cells, the Golgi apparatus, along with other organelles, is suspended within the cytoplasm, the jelly-like substance that fills the cell and surrounds the nucleus.

Question 9: Which taxonomic rank is the next-smallest after Order?

Phylum
Family (Correct answer)
Species
Genus

Correct answer: Family

The Linnaean classification system organizes life into a hierarchical structure: Kingdom, Phylum, Class, Order, Family, Genus, Species. Following this sequence, Family is the taxonomic rank that is immediately smaller and more specific than Order.

Question 10: Which of the examples below best exemplifies the idea of carrying capacity?

A population of mosquito decreases because of a lack of water available following a drought-stricken summer.
A population of roaches decreases due to exposure to an insecticide resulting in the extermination of roaches in an area.
A population of rabbits increases from 4 rabbits, to 25 rabbits to 100 rabbits in three months.
A population of deer increases exponentially, but then decreases due to starvation, then increases slightly again. (Correct answer)

Correct answer: A population of deer increases exponentially, but then decreases due to starvation, then increases slightly again.

Carrying capacity is the maximum population size of a species that an environment can sustain indefinitely, given the available resources. The scenario where a deer population initially increases exponentially but then declines due to starvation (resource limitation) before potentially stabilizing, perfectly illustrates the concept of an environment's carrying capacity being reached and exceeded.

Question 11: Which is more likely to happen after people move in and out of a community near an open body of water?

the population will decrease if the rate of immigration is greater than the rate of emigration.
the population will increase if the rate of immigration is greater than the rate of emigration. (Correct answer)
the population will increase if the rate of immigration is less than the rate of emigration.
the population will remain the same if the rate of immigration is equal to the birth rate.

Correct answer: the population will increase if the rate of immigration is greater than the rate of emigration.

Population dynamics are influenced by birth rates, death rates, immigration (people moving in), and emigration (people moving out). If the rate of immigration into a community is greater than the rate of emigration from it, more individuals are entering than leaving. This net influx of individuals will lead to an overall increase in the community's population.

Question 12: Which of the following is most likely to be happening in populations that are supposedly in a zero growth phase?

the death and emigration rates equal the birth and immigration rates. (Correct answer)
the birth rate equals the immigration rate.
the death rate equals the emigration rate.
the infant mortality rate equals the emigration rate.

Correct answer: the death and emigration rates equal the birth and immigration rates.

A population in a zero growth phase experiences no net change in its total size. This occurs when the number of individuals added to the population (through births and immigration) is exactly balanced by the number of individuals removed from the population (through deaths and emigration). Essentially, the sum of additions equals the sum of removals.

Question 13: Which of the following will be brought on by an aortic dissection?

oxygenated blood would not be transported to the body’s cells. (Correct answer)
oxygenated blood would not be transported to the heart’s atria.
deoxygenated blood would not be transported to the heart.
deoxygenated blood would not be transported to the lungs.

Correct answer: oxygenated blood would not be transported to the body’s cells.

An aortic dissection is a serious condition where there is a tear in the inner layer of the aorta, the body's largest artery. The aorta is responsible for carrying oxygenated blood from the heart to all other parts of the body. A dissection impairs this crucial function, meaning oxygenated blood would not be effectively transported to the body's cells.

Question 14: Which of the following structures is crucial for regulating the peripheral nervous system's autonomic functions?

medulla oblongata (Correct answer)
hypothalamus
pons
thalamus

Correct answer: medulla oblongata

The medulla oblongata is a critical part of the brainstem that plays a vital role in regulating many involuntary autonomic functions essential for life. These functions include controlling heart rate, breathing, blood pressure, and reflexes like vomiting and swallowing, all of which are part of the peripheral nervous system's autonomic control.

Question 15: Which of the following would be less limiting than an organism's family under Linnaeus' classification scheme?

taxon
order (Correct answer)
genus
species

Correct answer: order

Linnaeus's classification system arranges organisms into a hierarchy from broadest to most specific: Kingdom, Phylum, Class, Order, Family, Genus, Species. An 'order' encompasses multiple 'families,' meaning it is a broader and therefore less limiting taxonomic rank than a family.

Question 16: Which of the following species demonstrates a high fitness level?

a deer that has 90% viability of all offspring. (Correct answer)
a mule that produces infertile offspring.
a turtle species that reproduces in low numbers.
a cow that has 100% viability for male offspring.

Correct answer: a deer that has 90% viability of all offspring.

In biology, fitness is defined by an organism's ability to survive and, crucially, to reproduce viable offspring that can also reproduce. A deer with 90% viability of its offspring demonstrates high reproductive success, ensuring a strong contribution of its genes to the next generation, which is a key indicator of high fitness.

Question 17: Which of the following characteristics sets eukaryotes apart from prokaryotes?

the presence of ribosomes.
the presence of DNA.
the presence of a nucleus. (Correct answer)
the presence of proteins.

Correct answer: the presence of a nucleus.

The most fundamental characteristic distinguishing eukaryotic cells from prokaryotic cells is the presence of a true, membrane-bound nucleus. Eukaryotes house their genetic material (DNA) within this nucleus, while prokaryotes lack a nucleus and their DNA is located in the cytoplasm.

Question 18: Which of the following organelles would be used in cellular respiration, the process that generates cellular energy?

mitochondria (Correct answer)
ribosome
nucleolus
chloroplast

Correct answer: mitochondria

Cellular respiration is the metabolic process that converts glucose and oxygen into ATP, the primary energy currency of the cell. This vital process primarily occurs within the mitochondria, often referred to as the 'powerhouses' of the cell, making them essential for generating cellular energy.

Question 19: Which of the following is accurate of both mitochondria and chloroplasts?

they have an impermeable membrane and contain single stranded DNA.
they have a double membrane and contain maternal DNA. (Correct answer)
they are both in animal cells.
they have a single membrane and contain only RNA.

Correct answer: they have a double membrane and contain maternal DNA.

Both mitochondria and chloroplasts are unique organelles that possess their own circular DNA, ribosomes, and are enclosed by a double membrane. They are believed to have originated from endosymbiotic events, and their DNA is typically inherited maternally, supporting their ancient bacterial origins.

Question 20: Which of the following, according to Darwin's research, best explains the differences in the finches he saw in the Galapagos islands?

the differing climates and vegetation on each island. (Correct answer)
the presence of humans on each island.
the amount of sunlight available on each island.
the presence of predators on each island.

Correct answer: the differing climates and vegetation on each island.

Darwin observed that the finches on the Galapagos Islands had distinct beak shapes and sizes, which were perfectly adapted to the specific food sources available on each island. These differences in climate and vegetation across the islands created varying environmental pressures, leading to the natural selection of different beak types best suited for survival and reproduction in each unique habitat.

Question 21: Which of the following germ layers divides to form the muscles during embryonic development?

ectoderm
interoderm
endoderm
mesoderm (Correct answer)

Correct answer: mesoderm

During embryonic development, the mesoderm is one of the three primary germ layers, located between the ectoderm and endoderm. This middle layer is responsible for forming a wide array of tissues and organs, including all types of muscles (skeletal, smooth, and cardiac), bones, cartilage, and the circulatory system.

TEAS Science Practice Test #3

A scientist found that when an invasive species was introduced into a river, the population of salmon native to the region decreased.
The type of correlation between these two populations could best be described as