Free HiSET Science Practice Questions

Sample Practice Questions

Try these 10 sample questions from the HiSET Science practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1A survey counts 240 frogs of one species in a pond covering 12 square meters. What is their population density?

   1. A.20 frogs per square meterCorrect answer: A
   2. B.12 frogs per square meter
   3. C.240 frogs per square meter
   4. D.2,880 frogs per square meter

   Explanation: OpenStax states, "population density, the number of individuals within a specific area or volume". Divide 240 individuals by 12 square meters to obtain 20 frogs per square meter.

   Reference: Biology 2e: Population Demography — Section 45.1, Population Size and Density

2. 2A sample has a mass of 36 g and occupies 12 cm³. What is its density?

   1. A.24 g/cm³
   2. B.12 g/cm³
   3. C.3 g/cm³Correct answer: C
   4. D.432 g/cm³

   Explanation: OpenStax states, "The density of a substance is the ratio of the mass of a sample of the substance to its volume". Dividing 36 g by 12 cm³ gives 3 g/cm³.

   Reference: Chemistry 2e: Measurements — Density

3. 3Which description best distinguishes a mineral from a rock?

   1. A.A mineral has an orderly internal structure; a rock is an aggregate of mineral matterCorrect answer: A
   2. B.A mineral is an aggregate of rocks; a rock is an individual mineral
   3. C.A mineral must contain several compounds; a rock must consist of a single element
   4. D.A mineral has no characteristic composition; a rock always has one

   Explanation: USGS states, "A mineral is a naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties." It also states, "A rock is an aggregate of one or more minerals, or a body of undifferentiated mineral matter."

   Reference: What Is the Difference Between a Rock and a Mineral? — Definition of mineral and rock

4. 4A complete census counts all 90 animals of the same species living in a forest. What does the number 90 describe?

   1. A.Population density
   2. B.Population sizeCorrect answer: B
   3. C.Age structure
   4. D.Mortality rate

   Explanation: OpenStax states, "population size (N), the total number of individuals". The count gives the total number of individuals, not a count per unit area.

   Reference: Biology 2e: Population Demography — Section 45.1, Population Size and Density

5. 5A uniform block is cut into two equal pieces at the same temperature. How does the density of either piece compare with the original block?

   1. A.It becomes four times as great
   2. B.It becomes half as great
   3. C.It becomes twice as great
   4. D.It remains the sameCorrect answer: D

   Explanation: OpenStax states, "The density of a substance is the ratio of the mass of a sample of the substance to its volume". Halving a uniform block halves both mass and volume, so their ratio remains unchanged.

   Reference: Chemistry 2e: Measurements — Density

6. 6A specimen formed when lava cooled at Earth's surface. What kind of rock is it?

   1. A.Intrusive igneous
   2. B.Extrusive igneousCorrect answer: B
   3. C.Clastic sedimentary
   4. D.Metamorphic

   Explanation: USGS states, "Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earth's surface". Cooling lava at the surface forms extrusive igneous rock.

   Reference: What Are Igneous Rocks? — Extrusive Igneous Rocks

7. 7In a closed population with no immigration or emigration, 50 individuals are born and 20 die during a year. What is the net population change?

   1. A.No change
   2. B.A decrease of 30
   3. C.An increase of 30Correct answer: C
   4. D.An increase of 50

   Explanation: OpenStax states, "the population size will increase if birth rates exceed death rates". With no migration, subtract 20 deaths from 50 births for a net increase of 30.

   Reference: Biology 2e: Population Demography — Demography

8. 8A fully submerged stone raises water in a graduated cylinder from 25 mL to 34 mL. What is the stone's volume?

   1. A.9 mLCorrect answer: A
   2. B.25 mL
   3. C.34 mL
   4. D.59 mL

   Explanation: OpenStax states, "displacing a volume of water equal to its own volume". The rise in water level is 34 minus 25, or 9 mL.

   Reference: Chemistry 2e: Measurements — Using Displacement of Water to Determine Density

9. 9Why do slowly cooled intrusive igneous rocks often have coarse mineral grains?

   1. A.Slow cooling dissolves crystals as soon as they form
   2. B.Slow cooling prevents crystals from forming
   3. C.Slow cooling allows more time for crystals to growCorrect answer: C
   4. D.Slow cooling shortens the time available for crystal growth

   Explanation: USGS states, "Slow cooling means the individual mineral grains have a very long time to grow". Long cooling times allow larger crystals to develop.

   Reference: What Are Igneous Rocks? — Intrusive Igneous Rocks

10. 10Which pattern describes a Type III survivorship curve?

    1. A.Most deaths occur in middle age
    2. B.Most individuals die at older ages
    3. C.Death occurs equally across ages
    4. D.Most individuals die at young agesCorrect answer: D

    Explanation: OpenStax states, "Trees, marine invertebrates, and most fishes exhibit a Type III survivorship curve because very few of these organisms survive their younger years". Type III shows high early mortality.

    Reference: Biology 2e: Population Demography — Section 45.1, Survivorship Curves