Biology Practice Questions

Strep throat is a common human illness often caused by the bacterium Streptococcus pyogenes. Which term best classifies the colonies of Streptococcus pyogenes in a person with strep throat? A. a population B. an organelle C. a community D. an ecosystem

A A. Key: A population is composed of individuals of the same species (Streptococcus pyogenes bacteria colonies) within a habitat (a person's throat). B. An organelle is a component of a cell. C. A community is represented by different populations interacting within the same habitat. D. An ecosystem includes all the living parts of a habitat along with the nonliving parts of the habitat that support life.

Which structure and function are common to all plants and some protists and distinguish them from all animals? A. chloroplasts that conduct photosynthesis B. mitochondria that conduct photosynthesis C. chloroplasts that conduct cellular respiration D. mitochondria that conduct cellular respiration

A A. Key: Chloroplasts, which are absent in all animal cells, convert light energy into chemical energy within all plants and some protists. B. Mitochondria perform cellular respiration in all eukaryotic cells, not photosynthesis. C. Chloroplasts, which are absent in all animal cells, perform photosynthesis—not cellular respiration. D. Mitochondria perform cellular respiration, and they are a shared characteristic among plants, protists, and animals.

Which statement best describes the process by which the millions of body cells that form a housefly can all contain the same genetic information? A. Original DNA is duplicated during replication and then distributed into two new cells. B. Original RNA is duplicated during replication and then distributed into two new cells. C. Original DNA is duplicated during replication and then distributed into four new cells. D. Original RNA is duplicated during replication and then distributed into four new cells.

A A. Key: DNA replication produces two copies of genetic information that are identical to the original DNA and are distributed into two new cells. B. DNA is duplicated during replication, not RNA. C. DNA replication produces two copies that are distributed to two new cells, not four. D. DNA, not RNA, is duplicated during replication and distributed to two new cells.

A G T G C C G A C arrow original strand A G G C C G A C arrow altered strand 4. A section of DNA in a cell is altered. Which mutation is being illustrated in the DNA section above? A. deletion B. insertion C. duplication D. nondisjunction

A A. Key: The altered strand of DNA is shorter than the original strand; this suggests that one or more bases were deleted. B. An insertion mutation involves the addition of one or more bases to the DNA strand, making it longer. C. A duplication occurs when a section of DNA is copied one or more times, making the strand longer. D. Nondisjunction results in one daughter cell having too many chromosomes or chromatids and the other having none.

Which statement describes how a mutation would most likely affect a population? A. Genotypic variation will increase in the population. B. Genotypic variation will decrease in the population. C. The occurrence of a preexisting gene will increase in the population. D. The occurrence of a preexisting gene will decrease in the population.

A A. Key: When a mutation occurs within genes, it generates new genotypic variations within the population. B. Mutations typically increase, not decrease, genetic variation. C. There is not enough information provided to predict frequency changes of preexisting genes. D. There is not enough information provided to predict frequency changes of preexisting genes.

The enzyme pepsin is found in the stomach. Which medicine is most likely to directly interfere with pepsin's function? A. a medicine that affects pH B. a medicine that prevents clotting C. a medicine that blocks neural impulses D. a medicine that lowers cholesterol levels

A The enzyme pepsin is found in the stomach. Which medicine is most likely to directly interfere with pepsin's function? A. a medicine that affects pH B. a medicine that prevents clotting C. a medicine that blocks neural impulses D. a medicine that lowers cholesterol levels

Which process uses the products of photosynthesis as reactants? A. active transport B. cellular respiration C. DNA replication D. protein synthesis

B A. ATP, a product of cellular respiration, is used to fuel the process of active transport. B. Key: Glucose and oxygen are products of photosynthesis that are also reactants in cellular respiration. C. DNA replication is a semiconservative process that uses a single DNA molecule to produce two identical DNA double-helix molecules. D. The reactants in protein synthesis are amino acids, not the glucose and oxygen products of photosynthesis.

Which statement best describes how antibiotics affect cellular homeostasis? A. Antibiotics remove chloroplasts from plant cells to cause starvation. B. Antibiotics interfere with the transport of intracellular and extracellular materials. C. Antibiotics increase the rate of DNA replication in human cells by forming nucleotides. D. Antibiotics decrease the rate of cellular respiration in animal cells by producing oxygen

B A. Antibiotics work on bacterial cells, not plant cells. Antibiotics do not remove chloroplasts. B. Key: Homeostasis is maintained by different processes to regulate an organism's internal environment. The antibiotic action described in the scenario causes the cell wall to rupture and the cell to burst, so there can no longer be regulation of transport across the plasma membrane. C. Antibiotics do not affect the rate of DNA replication and do not function against human cells. D. Antibiotics do not produce oxygen and do not function against animal cells

. Which characteristic allows carbon atoms to form chains and rings with other carbon atoms? A. Carbon has several forms. B. Carbon can form four covalent bonds. C. Carbon is the fourth most abundant element in the universe. D. Carbon is a structural part of lipids, carbohydrates, proteins, and nucleic acids.

B A. Carbon has several forms, which is a result of its ability to form chains and rings with other carbon atoms. B. Key: Carbon forms a variety of chains and shapes because it can form four covalent bonds with its four valence electrons. C. Carbon's abundance makes it available for reactions, but carbon's chemical properties permit its bonding variety. D. Carbon's presence in the structures of major macromolecules is a result of its ability to form different types of bonds.

Which statement best describes a contribution that decomposers make to an ecosystem? A. They reduce the atomic mass of carbon atoms. B. They increase the recycling of carbon-containing molecules. C. They reduce the total number of carbon atoms in the atmosphere. D. They increase the total number of carbon nuclei within the atoms

B A. Decomposers release carbon into the atmosphere through respiration, but they do not change carbon's atomic mass. B. Key: Decomposers break down remains of once-living organisms, thereby releasing the carbon from those organisms back into the atmosphere during respiration. C. Decomposers add carbon atoms to the atmosphere when they release carbon during respiration. D. Each carbon atom has a single nucleus, which is unchanged by decomposers.

The presence of a specific trait is genetically inherited. There are only two possible outcomes for this trait: an individual either inherits the trait or does not inherit the trait. Which statement best describes how parents influence this trait? A. Each parent contributes two genes for this trait. B. Each parent contributes one allele for this trait. C. Each parent contributes two chromosomes for this trait. D. Each parent contributes one nitrogenous base for this trait

B A. Each parent contributes one gene for the trait, not two. B. Key: Each parent contributes one allele for the trait; alleles are different forms of the same gene. C. Each parent contributes half of the chromosomes to an offspring individual, and the chromosomes contain genes that code for specific traits. D. Each parent contributes many nitrogenous bases that compose the large and complex DNA molecule containing thousands of genes that code for traits.

The title of the diagram is, Cellulose Model. The diagram shows a chain consisting of multiple three part sequences of a rectangle connected to a hexagon connected to the letter "O". There are six rectangles, six hexagons, and five "Os" shown. 4. Cellulose is a carbohydrate and a polymer of glucose. Which statement best describes how cellulose is formed within living organisms? A. It is assembled by bonding individual atoms. B. It is constructed by connecting smaller monomer subunits. C. It is the product of the decomposition of a much larger molecule. D. It is the result of a physical change that alters the shape of a compound.

B A. Glucose is a monomer assembled by bonding individual atoms; cellulose is a polymer of glucose monomers. B. Key: Cellulose is a polymer, which is formed when many glucose monomers bond together. C. During decomposition, a cellulose polymer breaks down into smaller monomer subunits. D. Chemical changes that involve new bond formations between monomers produce polymers

Which statement is true for all prokaryotic and eukaryotic organisms? A. Both types of organisms transform energy from sunlight into chemical energy. B. Both types of organisms assemble proteins through transcription and translation. C. Both types of organisms are made of cells, tissues, and organs that work together. D. Both types of organisms have DNA contained within a nucleus as genetic material.

B A. Only some prokaryotic and eukaryotic organisms can transform energy from sunlight into chemical energy. B. Key: Both prokaryotic and eukaryotic organisms assemble proteins using transcription and translation involving RNA and ribosomes. C. Prokaryotes are single-celled organisms. D. Prokaryotes have genetic material within circular strands of DNA, but prokaryotes lack a nucleus.

Which transport mechanisms require the formation of a vesicle to transport material into or out of a cell? A. diffusion and osmosis B. exocytosis and endocytosis C. exocytosis and calcium pumps D. diffusion and facilitated diffusion

B A. Particle transport during diffusion and osmosis depend on the solute concentration inside and outside a cell. B. Key: Exocytosis and endocytosis both require the formation of a vesicle to carry materials into or out of a cell. C. Exocytosis requires a vesicle for material transport, but calcium pumps require energy and protein channels. D. Particle transport during diffusion depends on the solute concentration inside and outside a cell, and facilitated diffusion requires a carrier protein in the plasma membrane.

The graph represents the number of light brown and dark brown organisms living on the bottom of a clear, sandy lake 20 years ago. Over time, the lake bottom has become covered with dark sand and sediment. Which change has most likely occurred in the population? A. The number of light-brown individuals increased. B. The number of dark-brown individuals increased. C. The number of light-brown and dark-brown individuals increased. D. The number of light-brown and dark-brown individuals became equal

B A. The number of light-brown individuals decreased because they blended in less with the dark sand and sediment. B. Key: The number of dark-brown individuals increased because they blended in with the dark sand and sediment—enabling them to survive and reproduce. C. The number of light-brown individuals decreased, but the number of dark-brown individuals increased. D. It is unlikely that the number of light- and dark-brown individuals became equal because they are unequally adapted to blend into the environment.

Most prokaryotes and eukaryotes maintain a reserve of ATP. Which feature of prokaryotes and eukaryotes makes the ATP reserve necessary? A. They have cell membranes. B. They can change over time. C. They use energy to function. D. They have the ability to reproduce

C A. Cell membranes permit the movement of certain materials in and out of the cell without energy. B. Change over time is not a process that occurs within an organism's lifetime. C. Key: ATP is the energy currency of a cell, and both prokaryotes and eukaryotes depend on ATP to fuel their cellular functions. D. Reproduction primarily involves the distribution of genetic material to offspring cells.

The Golgi apparatus is broken down during mitosis and then reformed. Which function would a cell be unable to perform during the time that its Golgi apparatus is broken down? A. copying genetic material to include in the new cell B. forming vesicles to import molecules into the cell C. processing and packaging proteins for cellular export D. correcting errors in the process of building a new cell

C A. Copying genetic material to include in a new cell occurs in the nucleus. B. Vesicle formation to bring materials into the cell occurs at the plasma membrane. C. Key: The Golgi apparatus is responsible for modifying and packaging proteins for secretion from the cell. D. Both the ribosomes and the endoplasmic reticulum play a role in checking proteins for errors.

Which statement best describes a relationship between mitochondria and chloroplasts? A. Mitochondria release chemical energy from molecules and store it in chloroplasts. B. Chloroplasts release chemical energy from molecules and store it in mitochondria. C. Mitochondria convert chemical energy into light energy that can be used by chloroplasts. D. Chloroplasts convert light energy into chemical energy that can be used by mitochondria.

D A. Mitochondria release chemical energy to fuel cell processes; it is not stored in chloroplasts. B. Chloroplasts convert light energy into chemical energy in the form of glucose. C. Chloroplasts use light energy originally from the Sun, not from mitochondria. D. Key: Chloroplasts convert light energy into chemical energy (glucose), which is used by the mitochondria.

Which statement describes one difference between mitosis and meiosis in animal cells? A. Mitosis produces sex cells, and meiosis produces diploid cells. B. Mitosis produces haploid cells, and meiosis produces somatic cells. C. Mitosis produces four daughter cells, and meiosis produces two diploid cells. D. Mitosis produces two daughter cells, and meiosis produces four daughter cells.

D A. Mitosis produces somatic cells, and meiosis produces haploid cells. B. Mitosis produces diploid cells, and meiosis produces sex cells. C. Mitosis produces two diploid daughter cells, and meiosis produces four haploid daughter cells. D. Key: Mitosis produces two diploid daughter cells; meiosis produces four haploid daughter cells.

The Isthmus of Panama is a narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean. It forms a land bridge that links North and South America. The formation of this isthmus separated two bodies of water that had previously been connected. How did the formation of this land bridge most likely influence the development of distinct marine species on either side of the land bridge? A. by decreasing genetic drift B. by causing a founder effect C. by increasing the rate of genetic mutation D. by preventing related populations from interacting

D A. Separating populations of marine species may initially reduce their sizes, thereby increasing genetic drift. B. A founder effect occurs when a population's size is rapidly and drastically reduced; in this case, the populations were separated gradually and not drastically reduced in size. C. The rate of genetic mutation is unlikely to be affected by the gradual separation of a population. D. Key: Speciation often occurs when populations separate and are no longer able to interbreed due to physical barriers.

The function of which human organ is most like the cell walls of bacteria? A. heart B. liver C. pancreas D. skin

D A. The heart does not provide protection as a regulatory structure. B. The liver does not provide protection as a regulatory structure. C. The pancreas does not provide protection as a regulatory structure. D. Key: The cell walls of bacteria act as regulatory structures similar to the skin of humans.

A. ATP, a product of cellular respiration, is used to fuel the process of active transport. B. Key: Glucose and oxygen are products of photosynthesis that are also reactants in cellular respiration. C. DNA replication is a semiconservative process that uses a single DNA molecule to produce two identical DNA double-helix molecules. D. The reactants in protein synthesis are amino acids, not the glucose and oxygen products of photosynthesis.

D A. The plasma membrane allows the flow of light into or out of a cell. B. Oxygen is a small molecule and constantly diffuses into the cell for use in cellular respiration. C. Heat is a form of energy that moves without restriction in and out of a cell. D. Key: Water flow into or out of a cell is limited; it depends on the solute concentration inside or outside the cell.

Many plants have a waxy coating on their leaves. Which statement describes the most likely structure and function of the waxy coating? A. The waxy coating is a protein that can help attract other organisms for pollination. B. The waxy coating is a protein that can help release waste molecules during transpiration. C. The waxy coating is a lipid that can help absorb more sunlight in hot environments. D. The waxy coating is a lipid that can help prevent excess water loss in dry environments.

D Many plants have a waxy coating on their leaves. Which statement describes the most likely structure and function of the waxy coating? A. The waxy coating is a protein that can help attract other organisms for pollination. B. The waxy coating is a protein that can help release waste molecules during transpiration. C. The waxy coating is a lipid that can help absorb more sunlight in hot environments. D. The waxy coating is a lipid that can help prevent excess water loss in dry environments.

. State officials are considering constructing a road through a forested wilderness area. This action will likely affect the forest ecosystem in various ways. Part A. Predict how the construction of a road could negatively affect plants in the forest ecosystem. Part B. Predict how the construction of a road could negatively affect animals in the forest ecosystem. Part C. Describe one way that the construction of a road could have a positive effect on the forest ecosystem.

Many plants that are already living in the forest will be destroyed and gotten rid of in order to make room for the new road. The forest will have less organisms, and if one species existed in a concentrated area that happened to be where the road was constructed, the forest will also have less species because some might be killed out entirely from that area. Many animals will lose their homes by the construction of a road. Animals that live in underground burrows might lose their homes because the road will be built right overtop of them. Animals that live in plants and trees might lose their homes because they will have to be cut down in order to make room for the road. Also, animals might experience food shortages, as there will be much less plants for them to eat. These plants would be removed for the construction of the road, and certain animals might depend on those plants for survival, whether it be for food or shelter. Building a road through the forest might have the positive effect of letting more light in. Because several trees will be cleared away, there will be more open space and more areas where the sun and sky are not blocked out. Therefore, more plants might be given access to this new light and will grow more rapidly as well as more healthily, and even taller. Also, different species of plants that require excessive amounts of sunlight will be able to grow in these areas that were not previously able to grow there due to the canopy of trees.