3. We use the scientific method every day. Imagine your car doesn't start one morning before school. Which of these is a reasonable hypothesis regarding the problem?
B) I'm out of gas.
5. Carbon-14 is often used for carbon dating, where scientists measure the rate of carbon-14 decay to determine the age of items. It contains six protons and eight neutrons. During the process of carbon-14 decay, one of its eight neutrons becomes a proton and an electron is emitted. Which of the following is the BEST explanation of what has occurred?
B) The resulting atom is now a different element because the number of protons has changed.
9. Scientists now recommend a diet rich in antioxidants to stay healthy. What occurs at the atomic level to explain the reasoning behind this recommendation?
A) Antioxidants stop the chain reaction of cellular damage caused by free radicals.
11. The fact that salt dissolves in water is BEST explained by
B) the polar nature of water molecules.
12. Sweating is a useful cooling device for humans because
A) water takes up a great deal of heat in changing from its liquid state to its gaseous state.
****13. Which of the following correctly matches an organic polymer with its respective monomers?
A) protein and amino acids
****14. Which of the following BEST summarizes the relationship between dehydration reactions and hydrolysis?
A) Dehydration reactions assemble polymers and hydrolysis breaks them down.
15. Keratin and silk are examples of ___________ while glucose and sucrose are examples of _____________.
B) proteins; carbohydrates
****16. Why do cows have the ability to breakdown cellulose into glucose and humans can not digest cellulose?
C) Cows have special bacteria in their digestive tract that break down cellulose for them.
****17. Phospholipids are unusual and important to cell structure because
C) they have a polar and a nonpolar end.
****18. An example of a structural polysaccharide is____________, while an example of a disaccharide is __________.
B) chitin, table sugar
19. You go the store and buy some lard for cooking. You notice when you get home that the lard is solid at room temperature. What does this tell you about the fats in lard?
B) The lard is composed of saturated fats.
20. In a biological membrane, the phospholipids are arranged with the fatty acid chains facing the interior of the membrane. As a result, the interior of the membrane is
23. How is a denatured protein different from a normal protein?
B) A denatured protein has no secondary or tertiary structure.
25. You have discovered a new virus and have isolated its nucleic acids. What feature could you look for to determine if the nucleic acids of this virus are RNA or DNA?
C) If it is RNA, it will be single strand containing uracil.
26. Your friend is trying to learn about how to kill bacteria. She reads that preservatives such as citric acid are added to foods because the acidic environment kills bacteria by denaturing their proteins. She thinks this sounds like a lot of scientific jargon and asks if you know what this means. How can you explain?
B) Denaturing means that the proteins of the bacteria lose their structure and can't function, so the bacteria die.
27. The inner membrane of mitochondria have highly folded cristae, which is very similar to cells that line the intestine have many foldings in plasma membranes on the absorptive surface of the intestine. This is because
A) this will increase surface area to volume ratio, making chemical reactions effectively occur on the surfaces.
29. The cytoskeleton is to the cell what
A) bones are to humans.
B) a frame is to a house.
**D) A and B
****30. If all the lysosomes within a cell suddenly ruptured, what could occur?
A) The macromolecules in the cell cytosol would begin to degrade.
32. Researchers have been able to study the pathway of a secreted protein by "tagging" it with a fluorescent marker. Using this method, you would observe fluorescence moving from the ER to which organelle?
E) Golgi bodies
33. Which of the following is NOT TRUE about both mitochondria and chloroplasts?
B) Both capture the energy of sunlight to meet metabolic demands.
36. A biologist ground up some plant cells and then centrifuged the mixture. She obtained some organelles from the pellet in the test tube that took up CO2 and gave off O2. The organelles are most likely
37. DNA is located in which of the following?
A) prokaryotic cells
B) plant cells
C) animal cells
E) all of the above
****38. What is the function of a plant cell vacuole?
A) storage of nutrients
B) support of the cell
D) A and B
39. A cell from a wheat plant would contain which of the following?
A) Cell wall
D) A and B
E) A, B and C
2. The ________ portion of the cell membrane is responsible for the isolating functions of the membrane, while the ________ portion regulates exchange and communication with the environment.
A) lipid; protein
****3. According to the fluid mosaic model of cell membranes, which is the mosaic portion referred to?
5. About diffusion, which of the following statement is NOT right?
C) Diffusion can move molecules rapidly over long distances
7. Beaker A has a 10% sucrose solution, and beaker B has an 8% sucrose solution. Choose the correct statement.
B) Beaker B is hypotonic the Beaker A.
C) Beaker A is hypertonic to Beaker B.
*D) Both B and C are correct.
9. You fill a shallow tray with water and place a drop of red ink in one end of the tray and a drop of green ink in the other end. Which of the following is TRUE at equilibrium?
B) The red and green inks are both uniformly distributed throughout the tray.
10. Which of the following has potential energy?
A) water droplet on top of a waterfall
B) glucose molecule
C) 9V battery
D) all of the above
****12. When solid sodium hydroxide is added to water, the solution gets hot. This is an example of
B) an exergonic process.
13. Which of the following BEST illustrates the first law of thermodynamics?
A) the process of photosynthesis where solar energy is converted to chemical energy
B) the burning of fossil fuels to heat a home
C) the use of gasoline to allow your car to run
D) all of the above
18. Look at the chemical reaction curves below, which is an endergonic reaction?
The one starting high on the top and ending low with CO2+h2o
19. Sulfa antibiotics damage bacteria by affecting a certain bacterial enzyme. The sulfa antibiotic looks similar to a substrate normally required by the bacterial cells to live. The sulfa antibiotic occupies the active site of the required enzyme and blocks entry of its normal substrate. This prevents the bacteria from making nucleotides that are required for their reproduction and survival. Based on this information, the action of sulfa antibiotics is an example of
B) competitive inhibition
22. Imagine a plant in your garden doesn't receive an adequate amount of water. Which of the following would be most affected by this?
C) Both the light dependent and light independent reactions of photosynthesis
23. The pigment(s) that absorb light energy to drive photosynthesis is/are
D) A and B
****26. The final electron acceptor of ETC in cellular respiration is _______, while the final electron acceptor of ETCs in photosynthesis is _________.
C) O2 , NADP+
****28. The NADPH required for carbon dioxide fixation (C3 cycle) is formed
C) during the light reactions.
29. You are conducting an experiment to track what happens to the carbons from CO2 molecules used in the light independent reactions of photosynthesis. You add a radioactive tag to the carbons of the CO2 reactants and then collect the products following the reactions. Which products would then be radioactive?
35. When sprint, your muscle cells perform ___________ fermentation, while yeast cells perform ___________ fermentation.
B) lactic acid, alcohol
36. Which of the following are examples of an electron carrier molecule?
D) both A and C
37. How many ATPs does the aerobic respiration generate when break down one molecule of glucose?
C) 36-38 ATPs
39. The function of electron transport chains in both cellular respiration and photosynthesis is to
A) generate energy
****1. The sequence of subunits in the DNA "backbone" is
2. The DNA of a certain organism has adenine as 40% of its bases. What percentage of its bases would be cytosine?
3. In the comparison of a DNA molecule to a twisted ladder, the rungs of the ladder represent
A) nitrogenous bases linked together
6. Which of the following are NOT involved in the leading strand during DNA replication process?
B) DNA ligase
7. __________ breaks the hydrogen bonds between complementary base pairs during DNA replication.
A) DNA helicase
10. If the sequence of bases in a section of DNA is TAGGCTAA, what is the corresponding sequence of bases in mRNA?
Suppose one strand of a "mini-gene" has the following base sequence: TACCCGGATTCA
12. The polypeptide encoded by this gene has how many amino acids?
****13. The anticodon of the tRNA that carries the first amino acid will be
14. The transcription start site is ______ and termination site is ______; while translation starts with a _____ and end with a ______.
A) promoter, terminator, start codon, stop codon
The central dogma is a framework for understanding the transfer of sequence information between DNA, RNA and protein. (see the picture.) Please label the name of each process from 1-3: DNA with circle around it=>RNA=>Proteins
C) replication, transcription, translation
16. A part of an mRNA molecule with the following sequence (5'-CCGACG-3') is being translated by a ribosome. The following activated tRNA molecules are available. Two of them can correctly match the mRNA so that a dipeptide can form
tRNA anticodon Amino acid
The dipeptide that will form will be
19. Diploid cells of the fruit fly Drosophila have 8 chromosomes. How many chromosomes does a Drosophila gamete have?
****20. Homologous chromosomes
A) exchange materials and pair up in meiosis I
B) don't exist in gamete cells
C) consist of two chromosomes the same size and with the same genes
D) all of these.
****26. Which event doesn't show up in mitosis?
A) Crossing over
B) Separation of homologues
D) both A and B
27. What are the major sources of genetic variation in sexual reproduction?
A) shuffling of homologues during meiosis I B) crossing over
C) random fusion of gametes D) A, B, and C all contribute genetic variation.
****28. According to the Law of Segregation, in an organism with the genotype Aa
C) half the gametes will have A and half will have a.
30. If the allele for inflated pea pods (I) is dominant to the allele for constricted (i), the cross Ii x ii is expected to produce
C) half with inflated and half with constricted pods.
Use the information below to answer the next 2 questions:
Plant height: T= tall and t= short,
Flower color: P= purple flowers, p= white flowers
We cross a short plant that is heterozygous for flower color with a plant that is heterozygous for both plant height and flower color.
****31. What proportion of the offspring would we expect to be tall and have purple flowers?
32. What proportion of the offspring would we expect to be short and have white flowers?
33. If you cross pea plants that are heterozygous for purple flowers and yellow seeds (PpYy), and you examine 800 offspring for flower and seed color, about how many do you expect to have white flowers and green seeds?
34. In humans, the sex of the offspring is determined by the
D) sex chromosome carried by the sperm cell.
35. In snapdragons, red x white → pink. This pattern of inheritance is explained by
B) incomplete dominance.
37. You cross a pea plant with genotype of YYSs with one having Yyss. (Y = yellow, y = green; S = smooth, s = wrinkled, where yellow is dominant to green, smooth is dominant to wrinkled). Please answer the following question:
What is the percentage of the offspring with heterozygous for both traits?
38. A disorder caused by non-disjunction of chromosome 21 resulting in a trisomy 21 child is
B) Down syndrome