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WorksheetsBiology Keystone Review
Total questions: 86
Worksheet time: 1hrs 22mins
Which action must occur for an enzyme to catalyze a chemical reaction?
a competitive inhibitor must first bind to an active site
a substrate must bind to an active site of the enzyme
a substrate must bind to an allosteric site of the enzyme
a noncompetitve inhibitor must first bind to an active site
Which characteristic is shared by both prokaryotes and eukaryotes?
have organ systems
make their own food
contain genetic material
need oxygen gas to breathe
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 forms only ionic bonds
carbon can form only ring structures
carbon can form four covalent bonds
carbon forms small, simple structures
Which statement correctly describes how a protein is formed?
a monosaccharide bonded to a side chain is broken apart
amino acids are bonded together in a long chain to form a new molecule
a molecule containing glycerol bonded to three fatty acids is broken apart
a nitrogenous base, a sugar, and a phosphate group combine to form a new molecule
Which biological molecules are most likely represented by molecules 1 and 2?
Molecule #1. made mostly of carbon with two nonpolar chains & a polar head ; main component of cell membrane
Molecule #2. polar molecule made of repeating units of sugar bonded to a phosphate & a nitrogenous base; stores genetic information
molecule 1: lipid molecule; molecule 2: nucleic acid
molecule 1: lipid molecule; molecule 2: protein
molecule 1: carbohydrate; molecule 2 nucleic acid
molecule 1; carbohydrate; molecule 2 protein
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?
more lipids would be digested
fewer lipids would be digested
the production of lipase molecules would increase
the production of lipase molecules would decrease
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?
Organisms #1: cell wall • endoplasmic reticulum • Golgi body • chloroplasts • mitochondria • nucleus • ribosomes • vacuole
Organism #2: cell membrane • endoplasmic reticulum • Golgi body • mitochondria • nucleus • ribosomes
Only organism 1 uses solar energy to make energy-rich compounds
Only organism 1 stores solar energy until it is needed for its life processes.
Only organism 2 produces molecules for long-term energy storage.
Only organism 2 transforms food energy into ATP during cellular respiration.
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?
Both processes produce carbon dioxide.
Both processes require energy directly from the Sun.
Products of one process are used as some of the reactants for the other process.
Thermal energy from one process is used as the energy source for the other process.
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 produced water
the reaction consumed water
the reaction caused an output of energy
the reaction required an input of energy
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.
Both directly connect the membrane to the nucleus of a cell.
Both use energy to continuously move water molecules out of a cell
Both cause the phospholipid bilayer to form a rigid membrane for a cell.
Which cell process is best modeled by the diagram?
osmosis
exocytosis
passive transport
facilitated diffusion
Some human diseases involve the unregulated growth of cells. Although some patients are not affected by these growths, many are harmed. Cells in harmful growths divide uncontrollably and can eventually invade other cells, tissues, and organs of the body. Some patients carry a mutation on one or more growth-suppressor genes (GSGs). GSGs help to repair damage to DNA. This mutation decreases the individual’s ability to fight these harmful growths. Recently, researchers reported on the results of using a combination of two types of medicine to treat patients with unregulated growths caused by a lack of functioning GSGs. When medicine X (large molecule, damages DNA) and medicine Y (large molecule, decreases enzyme activity) are used together, they cause the cell processes in the targeted cells to fail.
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
ribosomes
golgi apparatus
rough endoplasmic reticulum
Some human diseases involve the unregulated growth of cells. Although some patients are not affected by these growths, many are harmed. Cells in harmful growths divide uncontrollably and can eventually invade other cells, tissues, and organs of the body. Some patients carry a mutation on one or more growth-suppressor genes (GSGs). GSGs help to repair damage to DNA. This mutation decreases the individual’s ability to fight these harmful growths. Recently, researchers reported on the results of using a combination of two types of medicine to treat patients with unregulated growths caused by a lack of functioning GSGs. When medicine X (large molecule, damages DNA) and medicine Y (large molecule, decreases enzyme activity) are used together, they cause the cell processes in the targeted cells to fail.
Given the properties of the medicine Y molecule, which mechanism is most likely responsible for medicine Y’s entry into cells?
osmosis
exocytosis
active transport
simple diffusion
A group of students is given a sample of an unknown substance. The students are asked to gather evidence to determine whether the substance is living or nonliving. The students take a small sample of the substance and observe it using a microscope. What are two characteristics of the substance that could be observed to indicate whether it is living or nonliving.
the substance is made up of cells
the substance responds to stimuli
the substance is made up of carbon atoms
the substance is green
Most prokaryotes and eukaryotes maintain a reserve of ATP. Which feature of prokaryotes and eukaryotes makes the ATP reserve necessary?
they have cell membranes
they can change over time
they use energy to function
they have the ability to reproduce
Which structure and function are common to all plants and some protists and distinguish them from all animals?
chloroplasts that conduct photosynthesis
mitochondria that conduct photosynthesis
chloroplasts that conduct cellular respiration
mitochondria that conduct cellular respiration
Which characteristic allows carbon atoms to form chains and rings with other carbon atoms?
carbon has several forms
Carbon can form four covalent bonds
Carbon is the fourth most abundant element in the universe.
Carbon is a structural part of lipids, carbohydrates, proteins, and nucleic acids
Cellulose is a carbohydrate and a polymer of glucose. Which statement best describes how cellulose is formed within living organisms?
It is assembled by bonding individual atoms.
It is constructed by connecting smaller monomer subunits.
It is the product of the decomposition of a much larger molecule.
It is the result of a physical change that alters the shape of a compound.
Many plants have a waxy coating on their leaves. Which statement describes the most likely structure and function of the waxy coating?
The waxy coating is a protein that can help attract other organisms for pollination
The waxy coating is a protein that can help release waste molecules during transpiration
. The waxy coating is a lipid that can help absorb more sunlight in hot environments
The waxy coating is a lipid that can help prevent excess water loss in dry environments.
The enzyme pepsin is found in the stomach. Which medicine is most likely to directly interfere with pepsin’s function?
a medicine that affects pH
a medicine that prevents clotting
a medicine that blocks neural impulses
a medicine that lowers cholesterol levels
Which statement best describes a relationship between mitochondria and chloroplasts?
Mitochondria release chemical energy from molecules and store it in chloroplasts.
Chloroplasts release chemical energy from molecules and store it in mitochondria.
Mitochondria convert chemical energy into light energy that can be used by chloroplasts.
Chloroplasts convert light energy into chemical energy that can be used by mitochondria.
Which process uses the products of photosynthesis as reactants?
active transport
cellular respiration
DNA replication
protein synthesis
Which action is prevented by the plasma membrane?
the flow of light into or out of the cell
the flow of oxygen into or out of the cell
unlimited flow of heat into or out of the cell
unlimited flow of water into or out of the cell
Which transport mechanisms require the formation of a vesicle to transport material into or out of a cell?
diffusion and osmosis
exocytosis and endocytosis
exocytosis and calcium pumps
diffusion and facilitated diffusion
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?
copying genetic material to include in the new cell
forming vesicles to import molecules into the cell
processing and packaging proteins for cellular export
correcting errors in the process of building a new cell
Bacteria are single-celled microorganisms. The cell walls of these microorganisms serve as barriers to chemicals that might affect the processes that occur within a bacterial cell. Antibiotics are a type of substance used to stop bacterial growth. Some antibiotics cause the bacterial cell wall to rupture.
The function of which human organ is most like the cell walls of bacteria?
heart
liver
pancreas
skin
Which statement best describes how antibiotics affect cellular homeostasis?
Antibiotics remove chloroplasts from plant cells to cause starvation.
Antibiotics interfere with the transport of intracellular and extracellular materials.
Antibiotics increase the rate of DNA replication in human cells by forming nucleotides.
Antibiotics decrease the rate of cellular respiration in animal cells by producing oxygen.
Life functions are performed at many levels of biological organization. Which level of biological organization is the simplest level at which a structure can support life functions?
cell
tissue
organelle
organ system
The opening of the stomata allows water to evaporate from inside the leaf in a process known as transpiration. As this occurs, water molecules cling to one another and pull water in a continuous stream up the stem of the plant from the roots to the leaves. Which property of water makes this movement possible?
cohesion
freezing point
high specific heat
temperature-dependent density
In a Biological Reaction, tyrosine + valine + proline----> tyrosine, valine, proline bonded together by peptide bonds. Which statement best describes the event shown in the diagram?
Glucose is being synthesized in the chloroplast using nitrogen from plants.
Amino acid monomers are joining together to form a protein macromolecule.
A polymer in the nucleus is being broken into its individual monomer subunits.
Lipid molecules are forming fatty acid chains in a dehydration synthesis reaction.
Plant cells use sunlight to make their own food. Which structure allows plant cells to perform this function?
nucleus
vacuole
chloroplast
mitochondrion
Which statement best explains why cellular respiration in plants and other organisms is dependent on photosynthesis?
Photosynthesis is one of the final steps in cellular respiration.
Photosynthesis provides the materials that fuel cellular respiration.
Photosynthesis absorbs excess energy produced by cellular respiration.
Photosynthesis absorbs materials that are catalyzed during cellular respiration.
Molecules Needed for Protein Synthesis include
• mRNA • tRNA • amino acids • ATP molecules
A plant cell uses the molecules in the list to synthesize a protein. What role do the ATP molecules play in the protein synthesis process?
they provide energy
they increase activation energy
they convert energy into hereditary information
they absorb excess energy to prevent overheating
The indicated protein is part of a cell membrane. What is the most likely purpose of this protein?
It allows passage of particles into and out of the cell.
It manufactures phospholipids to repair membrane damage.
It releases stored chemical energy in membrane carbohydrates.
It attracts unbalanced electrical charges in the cell’s environment.
Which statement best describes how active transport differs from passive transport?
Only active transport requires ATP.
Only active transport moves small particles.
Only active transport relies on a plasma membrane.
Only active transport allows substances to leave a cell.
All living organisms must maintain homeostasis in order to survive. Which statement best describes one way humans maintain homeostasis?
Temperature is regulated by giving off carbon dioxide.
Water content is regulated by giving off carbon dioxide.
Temperature is regulated by sweating.
Water content is regulated by sweating.
Which characteristic of life is best shown by this diagram?
DNA is the genetic code in an organism.
An organism is made of one or more cells.
An organism responds to changes in its environment.
Changes occur in an organism as it grows and develops.
Which statement best explains why these cells have structural differences?
The cells have different functions.
The cells evolved in different organisms.
One of the cells develops into the other type of cell.
One of the cells is more primitive than the other cell.
Which of the following is a property of water that allows a water strider to walk on the surface of water?
solubility
cohesion
high specific heat
low freezing point
Which statement describes the formation of a protein molecule?
Amino acids combine to form a protein chain.
Fatty acid monomers dissolve to form a protein chain.
Fatty acid monomers combine to form a protein chain.
Amino acids dissolve monomers to form a protein chain.
Carbonic anhydrase is an enzyme involved in the reaction of carbon dioxide with water to form a molecule that dissolves well in the liquid part of blood. How does carbonic anhydrase affect this reaction?
by making the reaction reversible
by changing chemical products of the reaction
by increasing the time needed for the reaction to occur
by decreasing the amount of energy needed to complete the reaction
Which statement best describes this role of plastids in the plant cell?
Chloroplasts transform light energy into chemical energy.
Mitochondria transform light energy into chemical energy.
Chloroplasts transform chemical energy into electromagnetic energy.
Mitochondria transform chemical energy into electromagnetic energy.
Which two statements correctly describe one similarity and one difference between cellular respiration and photosynthesis?
1. Cellular respiration and photosynthesis both involve water.
2. Cellular respiration uses sugar, and photosynthesis produces sugar.
3. Cellular respiration and photosynthesis both use light to produce energy.
4. Cellular respiration requires light energy, and photosynthesis requires chemical energy.
1 and 4
1 and 2
2 and 3
3 and 4
What cell structure does all of the following:
• allows waste to exit the cell
• allows chemicals required for cellular respiration to enter the cell
• regulates movement of water into and out of the cell
lysosome
mitochondria
endoplasmic reticulum
plasma membrane
A jackrabbit has large ears containing blood vessels that help it maintain a constant body temperature by adjusting heat exchange with the surrounding environment. Which characteristic of life is best described by this example?
growth
energy use
organization
homeostasis
An exchange of genetic material between homologous chromosomes during Prophase I of meiosis; contributes to the genetic variability in gametes and in offspring
Crossing over
Nondisjunction
Gamete
Cytokinesis
The process in which DNA makes a duplicate copy of itself
Meiosis
Mitosis
DNA Replication
The process in which sister chromatids fail to separate during and after mitosis or meiosis
Meiosis
Nondisjunction
Crossing over
A change in the structure of a chromosome (e.g. deletion, inversion and translocation)
Cytokinesis
Nondisjunction
Chromosomal Mutation
A nuclear division resulting in the production of two somatic cells having the same genetic complement as the original cell
Meiosis
Mitosis
DNA replication
The longest lasting phase of the cell cycle in which a cell performs the majority of its functions, such as preparing for nuclear division and cytokinesis
Mitosis
Meiosis
Interphase
Using this diagram, which event most likely occurs next in mitosis?
The chromatin condenses
The nuclear envelope dissolves
The chromosomes double in number
The cell membrane pinches inward to divide the cytoplasm
Mitosis and meiosis are processes by which animal and plants cells divide. Which statement best describes a difference between mitosis and meiosis?
Meiosis is a multi-step process
Mitosis occurs only in eukaryotic cells
Meiosis is used in the repair of an organism
Mitosis produces genetically identical daughter cells
Which part of the apple flower produces cells by meiosis?
style- pollen tube grown down through style
anther- makes pollen containing sperm
stigma- traps pollen
filament- supports anther
Which statement best describes the phase of the cell cycle shown?
The cell is in prophase of MITOSIS because the number of chromosomes has doubled.
The cell is in prophase I of MEIOSIS because the number of chromosomes has doubled.
The cell is in telophase of MITOSIS because the cell is separating and contains two copies of each chromosome.
The cell is in telophase of MEIOSIS because the cell is separating and contains two copies of each chromosome.
