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154 Cards in this Set
- Front
- Back
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Which had to come first, invention of the microscope or development of our present cell theory? |
Invention of the microscope; microorganisms can be seen only with a microscope |
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A virus contains a DNA or RNA molecule surrounded by a protein coat. Viruses can only reproduce when inside a living cell. Are viruses alive? |
No; viruses cannot perform some of the basic functions of life (i.e. reproduction) on their own |
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Distinguish between magnification and resolution. |
Magnification involves making the image larger than the object; resolution is the ability to distinguish between objects that are very close together |
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Why are plant cells generally firmer than animal cells? |
A large water-filled vacuole presses up against the cell membrane and the cell wall creating turgor pressure |
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Distinguish between nucleoplasm and cytoplasm. |
Nucleoplasm is the substance inside the nucleus; cytoplasm includes the cytosol and organelles between the nuclear envelope and the cell membrane |
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Why do muscle cells contain more mitochondria than fat cells do? |
Because muscle cells use more energy than fat cells |
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What is the main difference between the structure of smooth endoplasmic reticulum and the structure of rough endoplasmic reticulum? |
Rough endoplasmic reticulum contains ribosomes; smooth endoplasmic reticulum does not |
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Distinguish between the functions of smooth endoplasmic reticulum and rough endoplasmic reticulum. |
Rough endoplasmic reticulum is a site of protein synthesis; smooth endoplasmic reticulum is thought to be a site of lipid synthesis |
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Why does a cell membrane not leak when it is punctured with a needle? |
Lipid and protein molecules of the phospholipid bilayer are in constant motion, and move in to fill the hole produced by the needle when it is removed |
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Describe apoptosis. |
Apoptosis is sometimes called cell suicide; lysosomes break open and digest the cell |
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KBr is an ionic compound. Name the bonds that hold the ions in KBr together. |
Ionic bonds |
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A glass can be filled with water above the rim without spilling. Why is this possible? |
Hydrogen bonds between water molecules hold the molecules together |
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Why is carbon so common in the molecules found in living organisms? |
Because it is the lightest element that can form four stable covalent bonds |
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What is the main difference between a monosaccharide and a disaccharide? |
A monosaccharide is a simple sugar (i.e. glucose); a disaccharide is a double sugar (i.e. maltose) |
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Why is it not a good idea to consume a diet rich in saturated fats and cholesterol? |
Because a diet rich in saturated fats and cholesterol has been linked to heart disease and stroke |
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What is an essential amino acid? |
An essential amino acid is an amino acid that cells cannot make from simpler substances; it must be obtained from ones diet |
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Why are prolonged high fevers dangerous? |
Because they may cause important enzymes to denature and lose their function |
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Distinguish between a polypeptide and a protein. |
A polypeptide is a chain of amino acids; a protein is a chain of amino acids that has taken on a three dimensional shape and a specific function |
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Define protein denaturation. |
Protein denaturation is a change in the shape of a protein that reduces its activity |
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Why does the amount of A always equal the amount of T in DNA? |
Because A always bonds to T, and C always bonds to G |
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What is the relationship between the nucleotide sequence in DNA and the amino acid sequence in a protein molecule? |
The nucleotide sequence in DNA determines the amino acid sequence in protein |
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Why do DNA molecules stay in the nucleus? |
To protect against DNA-destroying enzymes in the cytoplasm |
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Egg whites are liquid and are composed almost entirely of a protein called albumin. What happens to the albumin molecules in egg whites when an egg is fried? |
The albumin denatures |
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How is vegetable-oil margarine produced? |
Vegetable-oil is reacted with hydrogen |
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Why do producers add yellow food coloring to margarine? |
To make it look like butter |
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Hair is composed almost entirely of the protein keratin. When keratin is heated, its molecules are denatured and change their shape. How could this knowledge be put to practical use? |
Curly hair can be straightened, and straight hair can be curled |
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How are fruits and vegetables blanched? |
By placing them in boiling water for a brief period of time |
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Why would a food-processing company blanch potatoes before packaging them in transparent jars? |
Because blanching prevents the browning reaction |
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How does functional food differ from normal food? |
Functional food products claim to provide health effects in addition to the nutritional value of the food |
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Describe three common functional foods and the health claims associated with each. |
Ginkgo biloba "aids memory"; St. John's wort "balances personality"; Echinacea "relieves cold symptoms" |
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How is advertising linked to the problems associated with functional foods? |
Many believe that advertisers make unsubstantiated claims on food labels |
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List three medical conditions that developers of functional foods are targeting for functional-food production. |
Heart disease, osteoporosis, and high blood pressure |
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How can functional foods provide consumers with "too much of a good thing"? |
Some functional foods may produce effects that aggravate an already existing condition in a patient |
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What types of cells may be counted with a hemacytometer? |
Blood cells and yeast cells |
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What is the purpose of the grid etched into the base of a hemacytometer counting chamber? |
It helps the technician keep track of counted and uncounted cells |
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Describe one advantage and one disadvantage of using a Coulter Counter rather than a hemacytometer to count cells. |
A Coulter Counter counts cells more quickly than a technician with a hemacytometer can; a Coulter Counter cannot be used to count very small cells such as bacteria |
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What is a stem cell? |
A stem cell is an undifferentiated cell that has the potential to become any other type of cell |
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How may stem cells be used to help humans? |
Stem cells may be used to produce transplant tissues |
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Explain how genes determine whether a cell is a stem cell or a specialized cell. |
The types of genes that are active (turned on) determine the identity of a cell |
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What are fibroblasts? |
A fibroblast is a type of skin cell |
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Why are fibroblasts of interest to transplantation biologists? |
They may be transformed into a number of other cell types such as bone and cartilage cells |
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What medical advantages do fibroblasts have over stem cells in transplantation? |
Adult bodies have a relatively small number of stem cells, but a very large number of fibroblasts. Fibroblasts are easy to obtain because they are in easily accessible skin. |
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What are some of the uses of bone and cartilage cells that have been made from fibroblasts? |
They can be used to replace bone lost due to gum disease and cartilage lost due to osteoarthritis |
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How does an enzyme affect the activation energy of the chemical reaction it catalyzes? |
It reduces the activation energy of the reaction it catalyzes |
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Why can a living cell not use large amounts of heat to speed up its chemical reactions? |
Heat may denature vital enzymes and reduce their functions |
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Name one substance that moves through cell membranes by facilitated diffusion. |
Glucose in liver cells |
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Why do some people add salt to a steak only after it has been cooked? |
Salt may form a hypertonic solution with steak juices, drawing water out of steak tissue by osmosis, producing a dry steak |
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Chemical fertilizers are composed of salts that dissolve into soil moisture and then are absorbed by the root cells of plants. Why should you never overfertilize a plant? |
Fertilizer may form a hypertonic solution in the soil that may draw water out of plant cells by osmosis, causing plant cells to die |
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A particular fish egg may be released in a saltwater environment where its size remains constant because the concentration of salt inside the egg is equal to the concentration outside the egg. If you put the egg in fresh water, what would happen and why? |
Fish egg would take on water by osmosis and may swell and burst |
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How is the rate of diffusion affected by an increase in temperature? |
Rate of diffusion increases |
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How is the rate of diffusion affected by a decrease in the concentration gradient? |
Rate of diffusion decreases |
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Why is it safe to inject a solution of 5% glucose directly into a vein, but not a solution of 20% glucose? |
At 5%, osmosis will not occur; 20% would cause osmosis out of the blood cells |
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Why does salted popcorn dry your lips? |
Salt dissolves in saliva, forming a hypertonic solution that draws water out of skin by osmosis |
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How does the filter paper of a tea bag act as a selectively permeable membrane when the bag is placed in a cup of hot water? |
Filter paper allows some tea solutes through to the water in the cup, but holds back small particles |
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What visual evidence is there that diffusion comes to an end during the tea-brewing process? |
Water surrounding the tea bag becomes more colored, then at some point it remains the same color |
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How do the produce departments of grocery stores help keep vegetables looking fresh and feeling crispy? |
By spraying fresh water on the vegetables periodically |
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Name one substance that is actively transported through the cell membrane of an animal cell. |
Sodium ions |
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What would happen to the size of the cell membrane if a cell were to undergo a lot of endocytosis and no exocytosis? |
Cell membrane would decrease in size |
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List two substances that cells export to the extracellular fluid by exocytosis. |
Hormones, enzymes |
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Name three large groups of organisms that carry out photosynthesis. |
Plants, plantlike protists, cyanobacteria |
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What is the name of the pigment molecule in green plants that begins the reaction of photosynthesis? |
Chlorophyll |
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What are accessory pigments? What is their role in photosynthesis? |
Light-absorbing molecules in plants (other than chlorophyll); they transfer light energy to chlorophyll |
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Name two accessory pigments and their associated colors. |
Yellow xanthophylls and orange carotenoids |
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What happens to the oxygen molecules formed during photosynthesis? |
Released to the atmosphere by plants |
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Why is it possible for organisms to carry out photosynthesis and cellular respiration but not photosynthesis only? |
Photosynthesis does not produce enough ATP to power all of the cellular processes of life |
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What is the key difference between aerobic respiration and anaerobic respiration? |
Aerobic respiration uses oxygen; anaerobic respiration does not use oxygen |
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Describe three cell processes that require the use of ATP. |
Protein synthesis, cell division, phagocytosis |
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Where in a cell do the reactions of glycolysis occur? |
In the cytoplasm |
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In which organelle do the reactions of oxidative respiration occur? |
In the mitochondria |
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How many ATP molecules are created in glycolysis from one glucose molecule? |
2 ATP molecules |
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How many ATP molecules are created in the overall process of aerobic respiration from one glucose molecule? |
36 ATP molecules |
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What is the cause of the pain and stiffness felt after strenuous exercise? |
The action of lactic acid on nerve cells |
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How many ATP molecules does a yeast cell obtain from every glucose molecule that undergoes ethanol fermentation? |
2 ATP molecules |
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Describe two ways in which humans make use of ethanol fermentation. |
Winemaking, bread making |
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Calculate the total magnification of a compound microscope when a 15X ocular lens and a 100X objective lens are in place. |
1500X |
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What are the functions of amyloplasts and chromoplasts in plant cells? |
Amyloplasts store starch; chromoplasts store colored pigment molecules |
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Name one type of cell that contains lots of mitochondria, and one type that contains few mitochondria. |
Sperm cells contain a lot of mitochondria; fat cells contain few mitochondria |
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Describe the location of chlorophyll molecules in a photosynthesizing plant cell. |
Embedded in thylakoid membranes in chloroplasts |
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If skin cells contain all of the genetic information to be nerve cells, why don't skin cells act like nerve cells? |
A different set of genes are active in skin cells than in nerve cells |
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How are stem cells unlike skin cells and nerve cells? |
Stem cells are not specialized; they have the potential to become almost any type of specialized cell |
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What are the differences between an oxygen atom and an oxygen molecule? |
An atom is composed of a single atom, but a molecule contains two oxygen atoms attached by a double covalent bond |
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List the following chemical bonds in order of increasing strength, from left to right: ionic bond, covalent bond, hydrogen bond |
hydrogen bond, ionic bond, covalent bond |
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Why is water called the universal solvent? |
Water dissolves more solutes than any other solvent |
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What does the saying "like dissolves like" mean? Provide one example that illustrates the saying's meaning. |
Polar solvents dissolve polar (and ionic) solutes; nonpolar solvents dissolve nonpolar solutes. Oil does not dissolve in water; alcohol dissolves in water. |
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What is an acid-base buffer? |
A solution that may neutralize small amounts of acids and bases |
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What are the components of an acid-base buffer? |
Approximately equal concentrations of an acid and a base |
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Describe a buffer that exists in the human body. |
Carbonic acid-bicarbonate buffer |
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How do plant cells and humans use cellulose? |
Plant - build cell walls; Humans - prevent constipation |
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What are the differences between the fatty acids in the triglycerides of oils and the fatty acids in the triglycerides of butter? |
Oil triglycerides are unsaturated or polyunsaturated; butter triglycerides are saturated |
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What is done to the fatty acids in vegetable oil to convert them into margarine? |
Are hydrogenated to convert them into margarine |
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Describe one similarity and one difference between a steroid and a fatty acid. |
Both are hydrophobic; steroids are ring molecules, while fatty acids are linear molecules |
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How do plants and animals use waxes? |
Plants use wax to create waterproof coatings; animals such as bees use waxes to build honeycombs |
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Explain how so many different proteins can be made with only 20 different amino acids. |
Identity of a protein depends on the number and the sequence of amino acids in its structure |
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How is the information in DNA used in protein synthesis? |
Sequence of nucleotides in DNA determines the sequence of amino acids in proteins |
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Why is the three-dimensional shape of a protein important? |
Creates crevices that act as active sites where substrates attach |
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What happens to proteins in the human body when they are heated above 40C? Why is this dangerous? |
They become denatured; denatured enzymes lose activity and cannot catalyze reactions effectively |
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How does cooking affect the proteins in a steak? |
Denatures the proteins in a steak, making the steak easier to chew |
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Briefly describe the role of DNA and RNA in the processing of genetic information. |
DNA stores genetic information; RNA takes information from the nucleus to ribosomes, where it is used to produce proteins |
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What does mRNA stand for? What does it do? |
Messenger RNA; transports the genetic information in DNA from the nucleus to the ribosomes in the cytoplasm |
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What role does ATP play in living cells? |
Transfers energy to energy-requiring reactions in a cell |
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What eventually happens to a cell if it does not produce adequate amounts of ATP? |
The cell will die |
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When does simple diffusion end? |
When the solute concentration is uniform throughout |
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Why does simple diffusion end? |
Particles move in all directions at the same rate |
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Does active transport reach a state of dynamic equilibrium? |
No, active transport uses energy to pump solute particles against a concentration gradient, and may cause all particles to go one way |
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What is the key difference between the transmembrane protein carriers of facilitated diffusion and the transmembrane protein carriers of active transport? |
Protein carriers of active transport require the use of ATP; facilitated diffusion carriers do not use ATP |
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If oxygen is available, what happens to pyruvate after it is formed by glycolysis in the cytoplasm of a cell? |
Enters a mitochondrion and is processed through the reactions of oxidative respiration |
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What series of reactions is common to both aerobic and anaerobic respiration? |
Glycolysis |
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How many ATP molecules are produced from one molecule of glucose in anaerobic respiration? |
2 ATP molecules |
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Where and under what conditions does lactate fermentation occur in humans? |
Muscle cells during strenuous exercise |
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Describe two practical uses of chitin. |
Biodegradable surgical stitches and some types of contact lenses |
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Why is the classification of organisms important? |
Allows scientists around the world to be exact when they are identifying/categorizing the same organism |
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What is meant by the term binomial nomenclature? |
A method of naming organisms by using two Latin names: the genus and the species; both are italicized |
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What change resulted in the six-kingdom system replacing the five-kingdom system? |
All bacteria were classified in kingdom Monera; the division of bacteria into Archaebacteria and Eubacteria resulted in the creation of a six-kingdom system |
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List, in order from most to least general, the seven levels of classification. |
Kingdom - Phylum - Class - Order - Family - Genus - Species |
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Why aren't viruses placed within the normal classification system? |
Most scientists do not consider viruses to be living organisms; only living organisms are classified in taxonomy systems |
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Explain the statement "archaebacteria thrive on extremes." |
Most archaebacteria thrive under extreme conditions that other organisms could not tolerate, e.g., without oxygen, in extremely hot environments, in extremely salty environments |
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List six ways in which archaebacteria contribute to human society. |
Digestion of sewage and oil spills; alternative fuel source; cancer research; production of bioplastics; production of enzymes for food processing, purfume manufacture, pharmaceuticals, and enzymes used in molecular biology |
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Where would you expect to find anaerobic bacteria in nature? |
In the absence of oxygen, without air circulation, e.g., in the soil, inside the body, inside a sealed container (e.g., home canning) |
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Why is conjugation considered a form of reproduction? |
Genetic material is exchanged through the pilus; the new organisms are genetically different from their parents |
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List the advantages of UHT milk. |
Transported and stored without refrigeration; bacteria destroyed; unopened container has a shelf life of 9-12 months; no additives or preservatives added; nutritional value is identical to fresh milk |
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What is the purpose of aseptic packaging in the UHT process? |
Aseptic packaging is a safe way of transporting and storing a perishable product |
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How are the industrial uses of microorganisms similar to the actions of microorganisms in nature? |
As bacteria metabolize, enzymes are released; in nature these enzymes promote decay of organic matter; in industry, these enzymes are harvested to produce consumer products |
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Describe the symptoms of E. coli 0157:H7 poisoning. |
Vomiting, cramps, bloody diarrhea, fever, death in some cases |
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List the sources of E. coli 0157:H7 contamination. |
Ground beef, processed meats, sprouts, leafy green produce, unpasteurized milk and juice, contact with cattle; drinking inadequately chlorinated water or swimming in contaminated lakes |
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Make a list of all body defences that fight bacteria. |
External (i.e., skin, sweat, mucus, cilia, tears); lymphatic system (i.e., tonsils, adenoids, lymph nodes, thymus, spleen, lymphocytes, macrophages); third line of defense (i.e., antigens, memory cells, plasma cells, antibodies) |
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How are the lymphatic and circulatory systems connected? |
Through a special circulatory system of vessels and nodes |
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List the main modes of disease transmission. |
Moisture droplets in the air, dust particles, direct contact; fecal contamination, animal bites or wounds |
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Describe three ways that vaccines are administered. |
Orally or by injection; genetically engineered into foods that are then eaten (e.g., banana with hepatitis vaccine, potato with cholera vaccine); can also be absorbed through the skin or nasal passages |
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List four examples of antibiotics. |
Penicillin, streptomycin, tetracycline, ciprofloxacin |
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How could you explain the increase of infections in hospitals by antibiotic-resistant bacteria? |
Is related to the greater exposure of microorganisms to antibiotics; mutations occur with each exposure, and, before long, a large population of resistant bacteria exists |
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What is the main feature used to classify Euglena as a plantlike protist? List five other identifying features of this organism. |
Chloroplasts; other identifying features: 1 or 2 flagella; eyespot; pellicle; central nucleus; contractile and food vacuoles; and mitochondria |
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What is the most important structural difference between algae and Euglena? between algae and land plants? |
Euglena is a single-celled organism; algae are multicellular organisms. Algae have no tissue structure, unlike plants, which are highly specialized into tissues. |
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Name a protist that feeds by phagocytosis and explain how this happens. |
Amoeba; pseudopods move toward, flow around, and engulf food particles; cell membrane pinches off to form a vacuole around the food, and, inside, enzymes digest the food |
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How are the sporozoans "parasitic"? |
Require at least one host, often two, to complete their life cycles; in some cases, the parasite reproduces asexually in one host and sexually in the other |
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An amoeba reproduces by binary fission about once every 24 h. How many amoeba would be produced from an original cell in a month of 30 days, assuming all survived and reproduced? |
536,870,912 new organisms, assuming all survived and reproduced |
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What main feature is missing that prevents fungi from being included in the plant kingdom? |
Fungi are heterotrophs (consumers) and lack the structures and ability to produce food |
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Hypothesize why a slice of store-bought bread might grow mould more slowly than a slice of homemade bread. |
Commercially made bread contains preservatives and mould retardants to extend shelf life |
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What is the effect of pesticide use on the diversity of microorganisms? |
Reduces the diversity of microorganisms directly, as these chemicals kill organisms in the soil; nutrient cycling is reduced and plant growth is affected; changes are seen in the food chain |
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What advantages does human insulin have over insulin produced from pigs or cows? What are the disadvantages? |
Does not produce the side effects associated with insulin produced from pigs or cows; this technology is expensive and is not yet universally available |
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Why is a host cell unable to make its own proteins while the invading virus replicates? |
Invading virus takes over control of the host cell and directs it to expend energy making viral particles; normal functioning of the host cell stops |
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List as many products as you can that rely on a bacterium for part of their production. |
Alternate fuel sources, acetone, bioplastics, stonewashed jeans, enzymes used in food processing (dairy products, vinegar), perfume manufacture, antibiotics and other pharmaceuticals |
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List six features of fungi that originally placed them in the plant kingdom. |
Eukaryotic; many cell organelles; cell walls; most are anchored in soil or other substrate; non-motile; reproduction can be asexual, sexual, or both |
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Humans have applied chemicals to crops for centuries, to stimulate plant growth and to kill pests. What effect does this treatment have on microorganisms? |
Kills microorganisms in the soil and decreases the natural coating of microorganisms on leaf surfaces |
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What two general ways are used to classify organs into organ systems? |
Related functions (physiology) or structures (anatomy) |
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Give an example of an organ that plays a major role in more than one organ system. |
Pancreas (digestive and endocrine); liver (digestive and excretory); blood vessels (circulatory and respiratory) |
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List 10 medical procedures that can be performed by endoscopic surgery. |
Ligament repair; gallstone removal; kidney stone removal; hernia repairs; spleen, appendix, and uterus removal; correction of spinal injuries; bladder, eye, and colon procedures; correction of birth defects; heart procedures |
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Explain how the body adjusts to cold external temperatures. |
Cold temperatures cause muscles to twitch (shivering); a decrease in blood flow to body surfaces; an increase in heart rate |
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Explain the difference between sensory neurons and motor neurons. |
Sensory - carry impulses from receptors such as the eye and ear to the central nervous system (brain and/or spinal cord); motor - carry impulses from the central nervous system to muscles/glands |
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What is a hormone? |
A compound released by one type of cell that travels through the bloodstream |
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Distinguish between a hormonal response and a nervous response. |
Hormonal response is slower and longer-lasting than a nervous response |
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What are the effects of stimulants and of depressants on heart rate and breathing rate? |
Stimulants increase heart rate and breathing rate; depressants decrease heart rate and breathing rate |
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Describe the short-term and potential long-term effects of alcohol on the body. |
Short term - slower heart rate, slower breathing rate, increased urine output; long-term - cirrhosis |
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Explain addiction as a response to chemical disruption in the brain. |
Nerve cells in the brain adjust to long-term exposure to a drug by producing fewer neurotransmitter receptor molecules, causing neurons to become less sensitive to the drug |
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What are the main functions of the digestive system? Name the end products. |
Break food down into nutrients that are then absorbed and transported by the circulatory system; glucose, amino acids, fatty acids, and glycerol |
