Study Guide

Sample Questions

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Competency 0001
Analyze the chemistry of living systems.

1. Commercial laundry detergents often contain enzymes to break down fabric stains. The addition of a lipase enzyme would be useful for treating a stain caused by which of the following substances?

  1. tomato
  2. blood
  3. grass
  4. oil
Correct Response: D. Enzymes are protein molecules that act as natural catalysts and lower the activation energy required by reactions. Lipase enzymes specifically interact with lipid molecules, such as oils, breaking down their hydrocarbon structure. This allows them to be more easily removed from fabrics.

Competency 0002
Analyze cell structure, function, bioenergetics, and cellular homeostasis.

2. The differentiation of early embryonic cells is most influenced by which of the following factors?

  1. the presence of maternal mRNA, proteins, and other substances in the cytoplasm of the unfertilized egg
  2. the loss of genetic material in some types of embryonic cells as the process of differentiation begins
  3. the physical movement of the egg within the mother, which results in implantation after fertilization
  4. the release of hormones from the mother, which act as signals to the cells of the developing embryo
Correct Response: A. Maternal mRNA, proteins, and other substances are present in the fertilized egg of many types of organisms. These molecules are referred to as cytoplasmic determinants and accumulate in certain areas within the developing embryo. As the cells of the growing embryo undergo cleavage, these cytoplasmic determinants are segregated into certain cells. The presence or absence of the cytoplasmic determinants affects subsequent cell differentiation.

Competency 0003
Demonstrate knowledge of the structures and functions of organisms, including their life cycles.

3. Which of the following tissue types reacts to the stimulus of a nerve impulse passing through a simple reflex arc?

  1. muscle
  2. blood
  3. brain
  4. epithelial
Correct Response: A. In a simple reflex arc, the body detects a stimulus and reacts automatically before the signal can be processed by the conscious part of brain. Usually, these actions are to prevent harm to the organism. During a reflex arc, the stimulus is conveyed to the spinal cord via sensory neurons, where the message is both carried to the brain and is partially redirected by relay neurons to the motor neurons in muscle, where a reactionary action then occurs.

Competency 0004
Analyze obtaining, storing, and using energy and matter to maintain homeostasis.

4. After an amoeba engulfs a bacterium, which of the following cell structures is directly involved in the digestive process?

  1. nucleus
  2. lysosome
  3. ribosome
  4. mitochondrion
Correct Response: B. Organelles called lysosomes contain digestive enzymes and play an important role in the digestive process of amoebas, a type of single-celled eukaryote. After a bacterium is engulfed, a food vacuole forms around the prey item. A lysosome then fuses with the food vacuole and digestive enzymes break down the bacterium, releasing nutrients to be utilized by the amoeba.

Competency 0005
Analyze populations and communities.

5. Use the graph below to answer the question that follows.

a graph of squirrel population changes over 7 years

A graphic is shown of the population size of squirrels over seven years. For the first year, the population rises from very low numbers to among the highest on the graph. Then, it lowers slightly before raising to about the same numbers between year 1 and 2. The same occurs between year 2 and 3. Just as the population is peaking in year 3, it plummets to about half its size before the year is halfway done. This puts the population's size at about its lowest point since founding when year 4 starts. Then, the population recovers slightly before lowering again between year 4 and 5. The same is repeated until year 7.

A population of squirrels living in a temperate forest utilizes acorns produced by oak trees as its primary food source and nest in the oak trees. Which of the following factors occurring in year 3 would result in the change in the carrying capacity shown on the graph?

  1. the occurrence of a drought that decreased acorn yield
  2. the gradual increase in number of deer also eating acorns
  3. the destruction of mature oak trees as the result of a fire
  4. the establishment of a new population of coyotes
Correct Response: C. Carrying capacity refers to the number of organisms that an environment can support based on environmental conditions and resource availability. When represented by a population curve, a population at carrying capacity often shows minor variations in an otherwise stable population size. A substantial decrease in population size that occurs over a short time period and that results in a new, lower carrying capacity is often the result of a sudden catastrophic event, such as a fire or other natural disaster.

Competency 0006
Demonstrate knowledge of ecosystems and biomes.

6. Which of the following changes in plant communities have been observed in North American forest ecosystems as a result of climate change?

  1. a decrease in the length of the growing season
  2. a delay in the development of leaves and flowers
  3. a latitudinal shift in the distribution of plant species
  4. an increase in the diversity of native species
Correct Response: C. One of the effects of climate change is a decrease in the number of days experiencing severely cold weather during the winter months. In North America, this has resulted in plants that are less frost-resistant being able to survive in latitudes further and further to the north as the decades have progressed.

Competency 0007
Analyze molecular genetics.

7. A strand of DNA begins with the nucleotide sequence  T A C A C C A C G A C C... . During replication, the "G" is not copied. This deletion would result in a:

  1. silent mutation.
  2. shift in the reading frame.
  3. substitution in the first amino acid.
  4. protein that is longer in length than normal.
Correct Response: B. The string of nucleotides that is read by the replication machinery is grouped into blocks of three nucleotides, each of which are codes for an amino acid. This pattern of groups of three nucleotides is called the reading frame. If one of the nucleotides is deleted, it changes how the nucleotides are grouped into sets of three, or shifts the reading frame. This will change which amino acids are coded for downstream of the deletion.

Competency 0008
Analyze patterns and processes of inheritance.

8. An advantage of sexual reproduction compared to asexual reproduction is that sexual reproduction:

  1. allows for more rapid colonization of new environments.
  2. requires less input from cellular energy.
  3. produces offspring with a shorter development time.
  4. increases the genetic diversity of offspring.
Correct Response: D. During sexual reproduction, the DNA from two parental cells is divided into four gametes as the result of meiosis and recombination. Each offspring thus receives only half of its DNA from each parent, with these halves combining to produce a new organism with a unique genetic makeup. In contrast, asexual reproduction does not involve the combination of genetic material from two parent organisms, so the resulting offspring exhibits a genetic make-up that is nearly an exact copy of the parental DNA. The variation that does exist is due to the random mutation associated with DNA replication.

Competency 0009
Demonstrate knowledge of biological evolution.

9. Natural selection differs from other processes of evolution, such as mutation, gene flow, recombination, and genetic drift, because natural selection:

  1. is nonrandom.
  2. primarily operates in large populations.
  3. is driven by adaptation.
  4. primarily operates over long time periods.
Correct Response: C. Natural selection is the process whereby forces, such as the environment or competing species, create a pressure that gradually changes the frequency of alleles in a population of a species. Generally, this means that, over time, the population becomes better adapted to that environment or better able to compete against other species. The other processes of evolution are random, like genetic drift, or are associated with other driving forces, such as mutations being caused by mutagens.

Competency 0010
Demonstrate knowledge of common ancestry and diversity.

10. Which of the following observations from the fossil record provides the strongest evidence that biological evolution has occurred?

  1. Transitional fossils share characteristics with similar species that lived in other time periods.
  2. Some fossil species are much more common than others at different points in time.
  3. Adaptive radiations are common throughout the fossil record.
  4. Few species present in the fossil record are still in existence.
Correct Response: A. A transitional fossil connects relative time periods in the fossil record and is any fossil that shows traits common to an ancestral fossilized species and its descendent groups. Any trait can be in common between the ancestral and descendent groups. These fossils are especially useful to connect groups with deep historical connections or that have other substantially different morphological features.

Competency 0011
Apply knowledge of chemistry concepts.

11. Which of the following substances is classified as a heterogeneous mixture?

  1. sand
  2. non-fat milk
  3. iodine
  4. table salt
Correct Response: A. A mixture consists of multiple substances that are not chemically combined. In the case of a heterogeneous mixture, the substances are not incorporated evenly, and the mixture has a non-uniform composition with clearly identifiable components, each of which having separate properties.

Competency 0012
Apply knowledge of physics concepts.

12. Two objects have charges of q subscript 1 and q subscript 2 respectively and are separated by a distance of 2 m so that they experience a force of magnitude F. The situation changes so that the distance between the objects is reduced to 1 m, and the charge of the first object is doubled. Which of the following expressions best represents the electric force between the two objects in the new situation?

  1. 2F
  2. 4F
  3. 8F
  4. 16F
Correct Response: C. Coulomb's law can be used to quantify the force between two charged objects using the equation F equals open parens K sub e Q sub 1 Q sub 2 close parens over open parens r squared close parens in which F is the force between the two charges, Q sub 1 and Q sub 2 are the values representing the amount of charge in each particle, r is the distance between the particles, and K sub E is Coulomb's constant. In this example, the distance is reduced by half and the charge on one of the objects is doubled, so these relative values can be used to determine the change in force by using the equation F equals 1 times 2 over 0.5 squared equals 2 over 0.25 equals 8 F.

Competency 0013
Apply knowledge of Earth science concepts.

13. Which of the following planets has an atmosphere that mainly consists of carbon dioxide?

  1. Saturn
  2. Mercury
  3. Jupiter
  4. Venus
Correct Response: D. The Venetian atmosphere is composed of approximately 96.5 percent carbon dioxide with nitrogen present as the second largest atmospheric component and trace gases comprising less than 1 percent of the atmosphere. As a result of the presence of large amounts of this greenhouse gas, Venus is the hottest planet in the solar system.