Biology Unit 2 Test

Organisms are classified based on whether they are made up of prokaryotic or eukaryotic cells. Which statement is correct about the organelles found in eukaryotic cells? A. Each type of organelle has a specialized function. B. All the organelles have a very similar size and shape. C. Each type of organelle can be found in all types of cells. D. All the organelles contain the same chemical compounds.

A. Each type of organelle has a specialized function.

The human body maintains a temperature of around 98.6 degrees at all times. Enzymes are involved in almost every chemical reaction in the body. Which of the following describes the connection between these two statements? A. Enzymes function best at a specific temperature. B. The body needs to be warm to prevent hypothermia. C. The body is kept relatively warm to prevent too much enzyme action. D. There is no connection between the two statements.

A. Enzymes function best at a specific temperature.

Like all theories, the cell theory is never accepted by scientists as an "absolute truth." Which statement best explains why? A. Future evidence may cause a theory to be modified or even rejected. B. A scientific theory is not based on experimental evidence or observations. C. A theory is only a collection of hypotheses that have been verified by experimentation. D. A theory evolves from collecting information, forming hypotheses, and then verifying the predictions of the hypotheses.

A. Future evidence may cause a theory to be modified or even rejected.

An allergic reaction causes the pH in a person's stomach to rise unexpectedly to 8. What effect would this change in pH have on pepsinogen, an enzyme that digests protein in the stomach? A. Pepsinogen would become completely inactive. B. Pepsinogen would convert proteins into amino acids. C. Pepsinogen would work more efficiently. D. Pepsinogen would prevent an allergic reaction to food

A. Pepsinogen would become completely inactive.

The effectiveness of enzymes as catalysts for metabolic processes is partly due to their structure. Which of the following describes the basic shape of an enzyme? A. Primary structure or linear chain B. Secondary structure or folding pattern C. Tertiary structure or globular shape D. Quaternary structure or two or more folded chains

A. Primary structure or linear chain

Which of the following is the most diverse group of macromolecules in both function and chemical structure? A. Proteins B. Lipids C. Carbohydrates D. Nucleic acids

A. Proteins

Which of the following is found in both prokaryotes and eukaryotes? A. Ribosomes B. Lysosomes C. Mitochondria D. Vacuole

A. Ribosomes

Students are given data from an investigation that identified some of the chemical elements present in four different samples. Which sample was most likely DNA? A. Sample 1 - Hydrogen, phosphorus, and nitrogen B. Sample 2 - Aluminum, silicon, and copper C. Sample 3 - Calcium, potassium, and nitrogen D. Sample 4 - Iron, oxygen, and magnesium

A. Sample 1 - Hydrogen, phosphorus, and nitrogen

The development of the cell theory was the result of which of the following? A. The work of a series of scientists over many years B. The invention of the microscope C. The discovery that all plants are composed of cells D. Virchow's idea that all cells must come from already existing cells

A. The work of a series of scientists over many years

What is one of the functions of nucleic acids? A. They transmit genetic information. B. They help produce energy within the cell. C. They regulate the flow of materials into the cell. D. They energize chemical reactions within the cells.

A. They transmit genetic information.

Like complex carbohydrates, proteins are macromolecules that serve many functions and can be chemically broken down and restructured. Both proteins and complex carbohydrates are which of the following? A. polymers of smaller subunits B. sequence of sugars C. lipids of large molecules D. nucleotides of DNA

A. polymers of smaller subunits

Baby food manufacturers sometimes use proteases in their products. Proteases catalyze the breakdown of the proteins in these foods, making digestion easier for infants. Proteases are which of the following types of molecules? A. protein B. fatty acid C. carbohydrate D. nucleic acid

A. protein

Stacey made a list of things she saw in a cell she was observing under the microscope. Stacey wrote down the following description of what she observed. 1. A large nucleus is visible in the center of the cell. 2. The cell is surrounded by a cell membrane. 3. The cell has the shape of a rectangle. 4. What appears to be a large space can be seen inside the cell. 5. The cell does not show any movement. 6. Increasing the light source reveals green dots inside the cell. Which statements did Stacey use to conclude that she was looking at a plant cell? A. 1, 3, and 5 B. 3, 4, and 6 C. 2, 4, and 6 D. 1, 5, and 6

B. 3, 4, and 6

Which formula below shows a carbohydrate? A. C2H2O2 B. C6H12O6 C. C21H38O6 D. C4N2H6O3 and 2 R groups

B. C6H12O6

Using a microscope in the science lab, Jill observed two unknown cells: Cell 1 and Cell 2. Cell 1 she identified as a plant cell and Cell 2 as an animal cell. Her teacher told her she identified the cells correctly. What did Jill most likely observe to correctly identify the cells? A. Cell 2 had a cell membrane and Cell 1 did not. B. Cell 1 had a cell wall and Cell 2 did not. C. Cell 2 had a chloroplast and Cell 1 did not. D. Cell 1 had a nucleus and Cell 2 did not.

B. Cell 1 had a cell wall and Cell 2 did not.

The illustration below shows the pigmented organelle in which photosynthesis takes place. What are these organelles called? A. Chlorophyll B. Chloroplasts C. Cristae D. Mitochondria (picture on classroom exit slips for October 4)

B. Chloroplasts

Some components of cells are listed. Which of the components could be observed using a microscope in a prepared slide of leaf epidermal cells but not in a prepared slide of human cheek cells? 1. Cytoplasm 2. Nucleus 3. Chloroplasts 4. Cell Wall 5. Cell Membrane A. Components 2 and 3 only B. Components 3 and 4 only C. Components 1, 2, and 3 only D. Components 1 and 5 only

B. Components 3 and 4 only

Each microscope has its advantages and disadvantages. Which microscope has allowed scientists to conduct systematic observations and provided them with the closest view of the structure of cells? A. Stereomicroscope B. Electron microscope C. Phase contrast microscope D. Compound light microscope

B. Electron microscope

Starch has several advantages as a polymer of glucose molecules. For example, starch can coil into a compact shape and is insoluble in water. These characteristics help starch perform its principal function. What is that function? A. Energy storage in animals B. Energy storage in plants C. Transport form of proteins in animals D. Support structure in plant

B. Energy storage in plants

Oils and waxes are formed from which of the following macromolecules? A. Monosaccharides B. Fatty acids C. Amino acids D. Nucleotides

B. Fatty acids

The invention of the microscope played an important part in developing the cell theory through the extensive design of investigations that confirmed observations with evidence. Which of the following is the most accurate statement about the nature and practice of science? A. Technology is required for gathering any data and the development of a scientific theory. B. New scientific information and/or continuous investigations influence the development of scientific theories. C. Scientific theories are ideas that have not been tested enough to become scientific laws. D. Scientific laws and theories both represent scientific information that is absolute and never changing.

B. New scientific information and/or continuous investigations influence the development of scientific theories.

Pepsin is an enzyme that works in the stomach. Pepsin breaks down proteins and is most efficient in an acidic environment. How will the addition of an antacid into the stomach affect pepsin's efficiency? A. Pepsin will work better with the addition of the antacid. B. Pepsin will not work as well because the stomach contents will become more basic. C. Pepsin will not work as well because the stomach contents will become more acidic. D. Pepsin will work just as efficiently because the antacid does not change the stomach contents.

B. Pepsin will not work as well because the stomach contents will become more basic.

Which type of molecule is used for catalyzing chemical reactions in the cell? A. Lipids B. Proteins C. Nucleic acids D. Carbohydrates

B. Proteins (1)

Which type of organic molecule is formed by strings of amino acids combined using dehydration synthesis? A. Lipids B. Proteins C. Nucleic acids D. Carbohydrates

B. Proteins (2)

An advertisement for a health supplement for dogs claims to build lean muscle and strengthen tendons and ligaments, as well as provide energy. Which two biomolecules must the supplement contain to provide these benefits? A. Carbohydrates and lipids B. Proteins and carbohydrates C. Nucleic acids and carbohydrates D. Lipids and nucleic acids

B. Proteins and carbohydrates

Robert Hooke first used the term cell in 1665. However, nearly 200 years passed before scientists developed the cell theory. Why did it take so long between the first use of the term cell and the development of the cell theory? A. Microscopes were not available for scientists to study the cellular structure of organisms. B. Scientists had to make many observations of various organisms before they could establish a theory. C. The development of the cell theory depended on scientists first developing the germ theory of disease. D. Scientists were more interested in studying the relationship of organisms to their environment rather than their structure.

B. Scientists had to make many observations of various organisms before they could establish a theory

Which of the following resulted from the invention of the microscope? A. The development of the theory of evolution B. The development of the cell theory C. Proof that cells can form spontaneously D. Proof that all cells have the same basic structure

B. The development of the cell theory

Water has special properties that make it essential for life on Earth. One of these properties is the behavior of water in its solid form as ice. Which of the following statements best explains why salt is poured on icy roads and sidewalks in the winter? A. The salt raises the freezing point of water. B. The salt lowers the freezing point of water. C. Saltwater cannot freeze at any temperature. D. Fresh water will not mix with saltwater.

B. The salt lowers the freezing point of water.

A plant and an animal are both living things. According to the cell theory, what can you conclude about these two very different organisms? A. Plants have cells but animals do not. B. They are both made of one or more cells. C. They both come from the same kind of cell. D. They both come from a non-living organism.

B. They are both made of one or more cells.

The table below shows the magnification of different types of microscopes. What can be concluded from this table? A. Compound microscopes have unlimited use. B. Transmission electron microscopes provide the most detail. C. Scanning electron microscopes provide the lowest resolution. D. All types of microscopes can be used to study the smallest details. (table on exit slip for October 1)

B. Transmission electron microscopes provide the most detail.

Ovalbumin is a protein found in eggs. Which of the following best describes the molecular structure of ovalbumin? A. a group of six carbon atoms joined in a ring. B. a chain of amino acids folded and twisted into a molecule C. a set of three fatty acids attached to a molecule of glycerol D. a sequence of nitrogenous bases attached to a sugar phosphate backbone

B. a chain of amino acids folded and twisted into a molecule

In pure water, a red blood cell from an animal will swell and burst, but a leaf cell from a plant will not. Which structure in the leaf cell is responsible for this difference? A. cell membrane B. cell wall C. mitochondrion D. nucleus

B. cell wall

The diagram below shows a monomer of a macromolecule. Which type of molecule contains these monomers? A. carbohydrates B. proteins C. nucleic acid D. lipid (has a picture on classroom for September 24)

B. proteins

Which of the following contain complex, membrane-bound organelles? 1. Bacteria 2. Viruses 3. Eukaryotic 4. Prokaryotic A. 1 and 2 B. 2 and 4 C. 3 only D. 4 only

C. 3 only

A key difference between plant and animal cells is that plant cells have cell walls and animal cells do not. This difference results in which of the following? A. Plant cells can form themselves into many different shapes in order to perform different functions. B. Plant cells cannot transport materials among other cells. C. Animal cells have increased flexibility for advanced cell or tissue specialization. D. Animal cells depend entirely upon cell membranes for structural support.

C. Animal cells have increased flexibility for advanced cell or tissue specialization

The endosymbiotic theory was proposed because mitochondria, chloroplasts, and free-living prokaryotes have similar A. Cell walls. B. Cell membranes. C. Cell DNA. D. Vacuoles.

C. Cell DNA

Organisms are classified as either prokaryotes or eukaryotes. Which of the following would you find in all prokaryotic cells and eukaryotic cells? A. Nucleus B. Cell wall C. Cytoplasm D. Mitochondria

C. Cytoplasm

Which of the following molecules is NOT a polymer? A. Cellulose B. Protein C. Glucose D. Glycogen

C. Glucose

Which of the following is NOT a principle included in the modern cell theory? A. New cells are formed only by the division of a pre-existing cell. B. The cell is the basic unit of structure and function for all organisms. C. Living cells appear spontaneously from non-living matter. D. All living things are composed of one or more cells.

C. Living cells appear spontaneously from non-living matter.

Which of the following structures is the best comparison of prokaryotes and eukaryotes? A. Prokaryotes are incapable of movement, while eukaryotes use flagella for movement. B. Prokaryotes have many internal membranes and compartments while eukaryotes have a large central vacuole. C. Prokaryotes have a few specialized structures while eukaryotes contain distinct organelles bound by a membrane. D. Prokaryotes have a pliable cell membrane while eukaryotes have a rigid cell wall.

C. Prokaryotes have a few specialized structures while eukaryotes contain distinct organelles bound by a membrane.

Many of the proteins in the human body are enzymes that catalyze chemical reactions. What is the relationship between enzymes and activation energy? A. When an enzyme catalyzes a reaction, it increases the activation energy of the reaction. B. When an enzyme catalyzes a reaction, it increases the activation energy of the product. C. When an enzyme catalyzes a reaction, it decreases the activation energy of the reaction. D. When an enzyme catalyzes a reaction, it does not affect the activation energy of the reaction.

C. When an enzyme catalyzes a reaction, it decreases the activation energy of the reaction.

Which type of molecule, shown below, stores and transmits genetic information in a cell? A. lipids B. proteins C. nucleic acids D. carbohydrates (has a picture on classroom for exit slip for September 27)

C. nucleic acids

Enzymes are important catalysts that change the rate of chemical reactions in cells. How do enzymes accomplish this important function? A. By preventing molecules from colliding B. By providing all the proteins required for a metabolic reaction C. By raising the required activation energy for a metabolic reaction D. By lowering the required activation energy for a metabolic reaction

D. By lowering the required activation energy for a metabolic reaction

Carbohydrates are excellent energy storage molecules. Why? A. The class of carbohydrates called disaccharides transport glucose from place to place in organisms. B. Sugars often serve as the building blocks for larger molecules. C. Carbohydrates consist of long chains of monomers. D. Carbohydrates contain many carbon-hydrogen bonds.

D. Carbohydrates contain many carbon-hydrogen bonds

Enzymes and nucleic acids have different functions. Which of the following best describes the difference between their functions? A. Enzymes are proteins that store the genetic code for protein synthesis while nucleic acids catalyze metabolic reactions. B. Enzymes store energy while nucleic acids release energy. C. Enzymes compose the bilayer formation of cell membranes while nucleic acids transport materials between cells. D. Enzymes are proteins that catalyze metabolic reactions while nucleic acids store the genetic code for protein synthesis.

D. Enzymes are proteins that catalyze metabolic reactions while nucleic acids store the genetic code for protein synthesis.

The endosymbiont theory is an explanation for some of the changes that occurred between the earliest cells on Earth and current cells on Earth. This theory, which is supported by a vast amount of scientific evidence, explains that mitochondria and chloroplasts had their origins as free-living organisms that were later incorporated into cells. How might further evidence change this theory? A. If more evidence supports the endosymbiont theory, it will become a scientific law. B. If more evidence supports the endosymbiont theory, it will become a scientific hypothesis. C. Evidence that does not support the theory will be disregarded because theories cannot be revised. D. Evidence that does not support the theory could cause the theory to be revised.

D. Evidence that does not support the theory could cause the theory to be revised.

Two of the four principal classes of organic compounds are proteins and nucleic acids. What is the relationship between proteins and nucleic acids? A. Nucleic acids use proteins for energy B. Nucleic acids are a subset of proteins C. Proteins are long polymers of nucleic acids D. Nucleic acids contain the information to make proteins

D. Nucleic acids contain the information to make proteins

Some bacteria live in hot springs. Their cells contain enzymes that function best at temperatures of 70 °C or higher. At the temperature of 50 °C, how will the enzymes in these bacterial cells most likely be affected? A. The enzymes will be destroyed by lysosomes. B. The enzymes will lose their bond structure and fall apart. C. The enzymes will require less energy to function than at 70 °C. D. The enzymes will not increase the rate of reactions as much as they would at 70 °C.

D. The enzymes will not increase the rate of reactions as much as they would at 70 °C.

A student conducts an experiment to measure the effect of temperature on the rate of catalyzed reaction for the stomach enzyme pepsin. Which graph shows the most likely result of this experiment (human body temperature is 37°C)? (all the pictures are one bell-ringer for September 30)

D. The graph has a higher incline

Many plants have waxy coatings on some surfaces. This coating reduces water loss because it is not water-permeable. This waxy coating is which of the following types of organic molecules? A. protein B. carbohydrate C. nucleic acid D. lipid

D. lipid