biology example keystones
Which statement best describes a direct role of ATP in a paramecium?
ATP provides the energy to move cilia.
Which mutation would most likely affect the organism's phenotype?
AUG-GCU-UGA
Which statement describes how cloning is different from selective breeding?
Cloning results in offspring genetically identical to the parents.
Which statement best describes how organisms use DNA and amino acids to synthesize a protein?
DNA is transcribed into mRNA, which is translated by the ribosome to produce an amino acid chain.
An ecologist wanted to know how many plants lived in a particular prairie. Instead of counting all the plants, the ecologist used a sample area. The ecologist placed a grid that was ten meters by ten meters in a random location in the prairie and counted the number of individual plants of the various species. Data were collected and recorded. Describe an observation from the prairie sample study.
Describing the number of plant individuals in the prairie (e.g., there are 2 wild bergamot in the prairie sample area)
Which statement best describes how geographic isolation can contribute to land animal speciation?
Geographic isolation physically separates populations and prevents them from interacting.
A male pistol shrimp with protective eye tissue pockets mates with a female shrimp without protective eye tissue pockets. All of the offspring have eye tissue pockets. Which statement is the most likely conclusion that can be made about the eye tissue pocket trait in pistol shrimp?
It is a dominant, autosomal trait.
Which process best describes the assembly of proteins from amino acids?
Monomers are linked to form a polymer.
Asian carp are an invasive species of fish. These large fish eat up to 40% of their body weight per day by feeding on phytoplankton. The carp also reproduce quickly. If these fish were to enter Lake Erie, how would the Presque Isle coastal ecosystem most likely be affected?
Most consumers in the ecosystem would face a shortage of food, and larger fish, such as walleye, would be unable to thrive.
Explain how natural selection could lead to the trait distribution shown in the circle graph.
Natural selection causes desirable traits to increase in frequency in the population, so trait 1 is likely the trait most favored by natural selection because individuals with this trait are more likely to survive and reproduce.
A student made lists of structures observed in cells from two different organisms. Which statement describes the most likely difference in the way that organism 1 and organism 2 obtain energy?
Only organism 1 uses solar energy to make energy-rich compounds.
Compare how both prokaryotes and eukaryotes use two of the cell structures listed and describe the common functions of these structures.
Plasma membrane - controls what moves in and out of the cell or provides a barrier around the cell or gives structural support to the cell
Ash from a volcanic eruption decreases the amount of available solar energy for a region. Which statement describes how a decrease in available sunlight will most likely affect ecosystems of this region?
Producer populations will decrease, causing a decrease in consumer populations.
Compare how both prokaryotes and eukaryotes use two of the cell structures listed and describe the common functions of these structures.
Ribosomes - synthesize proteins or perform translation
The genetic event shown in the diagram can occur during meiosis. Which statement best describes this type of event?
Segments of homologous chromosomes are exchanged, resulting in cells that will be genetically different.
The diagram shows the forelimbs of three animals. Which statement best describes the bones in the animals?
Similar bones in different organisms may have different functions.
Which statement best compares a carbohydrate and a nucleic acid?
The bonds in a carbohydrate store energy, and the sequence of nucleotides in a nucleic acid stores genetic information.
Some characteristics of life are shared by all organisms on Earth. Select two observations from the list and explain how each observation provides evidence to support a specific characteristic of life.
The rabbit is eating grass to obtain energy. Living organisms reproduce, and the robin reproduces by laying eggs
A scientist observed that during the course of a chemical reaction the number of ATP molecules was reduced. What did the scientist most likely learn from the observation?
The reaction required an input of energy.
Given the properties of the medicine Y molecule, which mechanism is most likely responsible for medicine Y's entry into cells?
active transport
lungs and capillaries both have porous linings that allow certain substances to move into or out of the structures. which function do these porous linings most likely serve in living organisms?
gas exchange
Which set of ecological organization levels is most likely to contain the largest variety of species?
multiple biomes in a biosphere
Two closely related shrimp species have habitats and niches that partially overlap. Which factor most likely caused the divergence of the shrimp into separate species?
reproductive isolation
The element carbon has multiple bonding patterns. Which bonding pattern cannot be formed by carbon?
C≡C≡C
Before cellular division, the cell must duplicate its DNA so that daughter cells will contain complete copies of the DNA. Which characteristic of DNA makes it most suitable as a molecule for this role?
DNA is made of two strands of complementary nucleotides.
Describe how electrons are involved in the formation of biological macromolecules.
Electrons are involved in forming covalent bonds between atoms, and covalent bonds are required to form biological macromolecules.
Which statement best describes a function of the proteins embedded in the plasma membrane of cells?
They selectively allow certain particles into and out of the cell.
Which student correctly compared the outcomes of meiosis and mitosis?
student 3
Four students classified the main energy conversions that occur during photosynthesis and cellular respiration. Which student best classified the energy conversions that occur in the two processes?
student 4
Which of the following is most involved in providing structure for a plasma membrane?
the arrangement of the hydrophobic and hydrophilic ends of the phospholipids
Which property of water is most responsible for plants being able to transport water from their roots to their leaves?
the attraction between molecules
During a cell division cycle, chromosome segments from two homologous chromosomes exchange places. Which result is most likely to occur following this cycle?
A change in gene location will occur on both chromosomes.
Explain how Enzyme A acts as a catalyst in the reaction. Be sure to include energy and time in your answer
Enzyme A acts as a catalyst by reducing the activation energy, or the energy that is needed to get the reaction started. (When the substrates attach to the enzyme's active sites, they are brought close together, facilitating the reaction.) The reaction takes less time to occur ("the reaction is faster" is also acceptable).
Lipase is an enzyme that breaks down lipids in the digestive system of humans. It functions best at a pH range of 4.0 to 5.0. When a person takes an antacid tablet to relieve heartburn, the antacid increases the pH to around 7 in certain areas of the digestive system. Which initial effect would most likely be caused by a change in pH?
Fewer lipids would be digested.
Microbes in the digestive system break down food, which allows nutrients to be absorbed by the body's cells. How will these body cells most likely be affected if an individual suffers from a high fever?
The body cells will bring in fewer nutrient molecules because the transport proteins lose their proper shape due to the high temperature.
Describe how the cell structures in this list can be used to classify the cell as either prokaryotic or eukaryotic. Use examples of the structures that would help identify the cell in your answer.
The cell is eukaryotic because it has a nucleus
An inversion occurs along part of a chromosome. How does the inversion most likely affect the region in which it occurs?
The information in the region is read differently during transcription.
Describe how the altering of the plant's genome by the scientists is similar to naturally occurring genetic mutations.
The naturally occurring mutation could cause a similar effect as the scientific duplicating of a gene.
The map shows some information about two ecosystems. Describe an abiotic characteristic that is similar in both the desert and the rainforest.
The presence of air is an abiotic characteristic that is similar in both a desert and a rainforest
Some scientists include the ability to adapt and evolve as a characteristic of life. Explain why the student would not likely make an observation at the park that would provide evidence to support this as a characteristic of life.
The process of evolving generally takes a long time and is carried out by a group of organisms over many generations, so this could not be observed during one park visit
Describe two characteristics of the substance that could be observed to indicate whether it is living or nonliving.
The substance is made of cells / is multicellular. The substance contains genetic material (DNA)
Which labels correctly complete the diagram?
Y is transcription, and Z is translation.
Plants are dependent on water. In most plants, water is absorbed by the roots and then moves up the stem of the plant and into the leaves by capillary action. Which properties of water are most responsible for the capillary action in plants?
adhesion and cohesion
At a point in the cell cycle, chromosomes have aligned near the middle of a cell. Which sequence of events will the cell need to complete to produce two identical daughter cells?
anaphase telophase cytokinesis
Many scientists have concluded that whales and dolphins have a more recent, common ancestor than do whales and sharks. Which characteristic most likely allowed scientists to make this conclusion?
anatomical structure
Orchids living in tropical rainforests often grow on the branches of trees to access sunlight. The trees are not affected by the orchids. Which term best classifies the relationship between the orchids and the trees?
commensalism
Tadpoles grown in ponds with high densities of tadpoles have lower survival and growth rates than tadpoles grown in ponds with lower densities of tadpoles. Which interaction between tadpoles grown in high-tadpole-density ponds would most likely cause the decreased survival and growth rates?
competition
Which characteristic is shared by both prokaryotes and eukaryotes?
contain genetic material
Which biological molecules are most likely represented by molecules 1 and 2?
molecule 1: lipid molecule 2: nucleic acid
A scientist observes a single-celled organism with several long, whip-like tails. Which function do the whip-like tails most likely perform for the organism?
movement through an environment
Which activity would a cell be unable to perform if a mutation occurred that caused the Golgi apparatus to stop functioning?
packaging proteins for transport out of the cell
Which action must occur for an enzyme to catalyze a chemical reaction?
A substrate must bind to an active site of the enzyme.
Which statement best describes how channel and carrier proteins in the plasma membrane are similar?
Both allow for the flow of molecules into and out of a cell.
Which statement best describes the outcomes of both meiosis and mitosis?
Cell division results in daughter cells that contain DNA.
Explain how altering the genome of a species has impacted the field of medicine.
It allows for more treatment options for genetic disorders using techniques like gene therapy.
Identify the maximum number of bonds one carbon atom can form.
One carbon atom can form a maximum of four bonds
What is the main purpose for initiating the production of folding helpers in a cell?
maintaining homeostasis
In order for medicine X to produce the effects that the researchers observed, it must have entered into which part of the targeted cells?
nucleus
Which sequence of steps is needed for the scientist's hypothesis about the absence of amphipods to eventually become a theory?
5, 1, 4, 2, 3
Describe a biotic characteristic that is unique to either a desert or a rainforest ecosystem.
A biotic characteristic that is unique to a rainforest ecosystem is the presence of bromeliads
Which condition would most likely result in an increase in the phenotypic variation within a population?
A mutation leads to individuals with genetic differences.
Which population description is most likely represented by the graph?
A population of birds quickly increases but then becomes stable due to limiting factors in the environment
Which statement best describes a relationship between enzymes and a simple biological reaction?
A reaction rate can be increased when the specific enzyme for a biological reaction is present.
Describe an inference from the prairie sample study.
A statement that relates the sample area to the entire prairie (e.g., The plants that have the most individuals in the prairie sample area have the most individuals in the entire prairie.)
The DNA Replication diagram is incomplete. Which nucleotide sequence accurately shows the DNA strand that would be produced during DNA replication?
AGGT
which of the following is essential to proper functioning of all prokaryotic and eukaryotic organisms?
ATP
Which statement correctly describes how a protein is formed?
Amino acids are bonded together in a long chain to form a new molecule.
Describe a difference between any observation and any inference.
An observation is a statement about the data that were measured, collected, perceived, or noticed using one of the five senses, but an inference is an assumption, not necessarily a fact, that is based on evidence gathered through observation.
Carbon is often considered the backbone of biological macromolecules. However, hydrogen is the most abundant element in the universe. Explain why the backbone of large macromolecules is made of carbon atoms rather than hydrogen atoms.
Because carbon atoms make four covalent bonds, they can form many types of backbones with many other atoms attached. Hydrogen can only make one covalent bond, so it cannot form chains or backbones.
Carbon can combine with many different elements but frequently combines with oxygen, hydrogen, and nitrogen to form organic molecules. Which statement best explains why carbon is able to form a large number of different molecules?
Carbon can form four covalent bonds.
Scientists predict that over time 0% of the population will have trait 2. Explain why this change in trait distribution could result in negative consequences for the population.
Having no individuals with trait 2 could have negative consequences for the population because genetic diversity is beneficial. If the environment changes in some way, it is possible that trait 2 would be the better trait to have in that new environment.
How does a mitochondrion facilitate the movement of some materials between cells?
It supplies the energy needed for moving molecules through membranes.
Describe how one part of Mendel's conclusion is consistent with current scientific knowledge of inheritance.
Mendel's "factors" are what we now call "alleles." We now know that alleles are found on chromosomes and that, in each cell of an individual, one set of chromosomes is from the mother and one set is from the father. So for each trait, an individual inherits one allele for that trait from the mother and one from the father.
Describe how one part of Mendel's conclusion is consistent with current scientific knowledge of inheritance.
Mendel's "factors" are what we now call "alleles." We now know that alleles are found on chromosomes and that, in each cell of an individual, one set of chromosomes is from the mother and one set is from the father. So for each trait, an individual inherits one allele for that trait from the mother and one from the father.
Some pistol shrimp within a population do not have eye tissue pockets. What role will natural selection most likely have in the frequency of the alleles responsible for the presence of tissue pockets in the shrimp population over time?
Natural selection will increase the allele frequency for tissue pockets because they are beneficial to the shrimp.
A cell in the leaf of a green plant performs both photosynthesis and cellular respiration, often at the same time. Which statement best describes how these processes are related to each other?
Products of one process are used as some of the reactants for the other process.
Describe an investigation that could be performed to classify the substance as living or nonliving.
Provide the substance with nutrients and check for growth (change in number or size of cells) over time
Select three changes experienced by the students and explain how each change can represent a homeostatic mechanism.
Sweating is a response to increased temperature. The evaporation of sweat cools the body (lowers the temperature). • Muscle cramps are a response to depleted electrolytes, dehydration, depletion of ATP, or build-up of lactic acid. The cramps will cause the person to slow down or stop, thus reducing the depletion of electrolytes, water, and ATP. • Decreased energy is a response to insufficient oxygenation of tissues, or depletion of fuel (glucose) or water. Fatigue will cause the person to slow down or stop, allowing time for the body to stabilize.
Which statement best explains why the carotenoid gene has been present in pea aphids for millions of years?
The HGT process introduced a benefit for survival and led to greater reproductive success in pea aphids with the carotenoid gene.
A student listed characteristics of a classroom aquarium ecosystem. Which characteristic is a biotic component of the aquarium ecosystem?
The ammonia is controlled with a filter that uses two types of bacteria.
Each cell in the human body contains thousands of different enzymes responsible for regulating reactions within the cell. Which statement explains why a single enzyme is unable to regulate a variety of reactions?
The binding of a substrate and an enzyme is specific.
In order to study genetic mutations, scientists must study genetic material. Which statement describes the genetic material scientists are most likely studying?
They study chromosomes that contain genes, which are DNA segments.
Explain how this process could impact agriculture in the United States.
This process could impact agriculture by reducing the demand for fossil fuels. Currently, fossil fuels are used extensively in agriculture, but if plants produce oil on a large scale, then the agricultural industry becomes more sustainable in terms of its fuel use.
Use information from the circle graph to infer which trait is most likely favored by natural selection.
Trait 1 is most likely favored by natural selection, since it is the more common trait.
Which statement best explains how organisms accomplish passing on traits to their offspring?
Traits are inherited by the transfer of genetic material from parent to offspring.
Since Mendel's paper was published, other forms of inheritance have been discovered. Describe two examples of how Mendel's conclusion does not fully explain the current scientific understanding of inheritance.
Traits that show incomplete dominance are not explained by Mendel's conclusions. In incomplete dominance, heterozygotes have a phenotype that is like a blend of the "recessive" and "dominant" phenotypes (e.g., displays an intermediate coloration between the dominant color and recessive color, such as red flower color, pink flower color, and white flower color for a species of plant). • Traits that show co-dominance are not explained by Mendel's conclusions. In co-dominance, heterozygotes have a phenotype that displays both the "recessive" and "dominant" phenotypes (e.g., a black rooster and white hen have "checkered" offspring).
Since Mendel's paper was published, other forms of inheritance have been discovered. Describe two examples of how Mendel's conclusion does not fully explain the current scientific understanding of inheritance.
Traits that show incomplete dominance are not explained by Mendel's conclusions. In incomplete dominance, heterozygotes have a phenotype that is like a blend of the "recessive" and "dominant" phenotypes (e.g., displays an intermediate coloration between the dominant color and recessive color, such as red flower color, pink flower color, and white flower color for a species of plant). • Traits that show co-dominance are not explained by Mendel's conclusions. In co-dominance, heterozygotes have a phenotype that displays both the "recessive" and "dominant" phenotypes (e.g., a black rooster and white hen have "checkered" offspring).
Trees are typically able to transport water from their roots to their stems and leaves. Which statement describes the property of water that most supports the transportation of water to all parts of a tree?
Water has strong attractions to itself and many other molecules.
Describe a relationship between a biotic component and an abiotic component in either a desert or a rainforest ecosystem.
Water is an abiotic component that must be ingested by all animals in either a desert or rainforest ecosystem
Whales have vestigial femurs and pelvic bones. Which statement explains why the vestigial structures are most likely present in whales?
Whales evolved over time from ancestors that lived on land.
Conditions around an enzyme change and affect the shape of the enzyme's active sites. Predict how this would affect the enzyme's ability to catalyze the reaction.
When the shape of an enzyme's active site is changed, the substrate cannot attach to the active site; it will not "fit." The enzyme would not be able to catalyze the reaction.
Energy pyramids describe food and energy relationships within an ecosystem. Which factor most likely limits the number of levels an energy pyramid can have?
energy loss between each level of organisms
which statement best compares eukaryotic cells and prokaryotic cells?
eukaryoyic cells contain membrane-bound organelles, and prokaryotic cells do not
Which cell process is best modeled by the diagram?
exocytosis
HGT can occur naturally in the wild but can also be accomplished in a laboratory setting. Which laboratory procedure most closely resembles the process of HGT?
inserting DNA from a bacterium into a corn plant
The shivering mechanism in bumblebees often serves the same purpose as it does in mammals. During which condition will the action of shivering most help a bumblebee to maintain homeostasis?
low environmental temperature
Which sequence best orders ecological categories from the one with the fewest number of individuals to the one with the greatest number of individuals?
population, community, ecosystem, biome
A student looking through a microscope records observations about a cell. Which stage of the cell cycle has the student described?
prophase