Review Questions Ch 1-11
Answers for all questions should be full and complete both for credit and for them to be useful preparation for the exam.
1. Describe the steps of the scientific method.
Observation of a phenomenon followed by the development of questions related to that phenomenon. Ex/ notice that my car won’t start – Why doesn’t my car start?
Research: Read the manual, talk to mechanics etc.
Formulation of a hypothesis: Form a supposition that concisely explains that observed phenomenon and is falsifiable (that is it can be tested and shown to be incorrect) Ex/ The battery is dead
Testing by experimentation: Design and carry out experiments that test the validity of the hypothesis. Be sure to establish a control to ensure that the variable tested is the variable responsible for your result. Ex/ Replace the battery and see if car starts. Test the battery in another car.
Development of a conclusiton: Evaluate the hypothesis in light of the data collected in experiments.
Communicate the results: Clearly and concisely state the previous research, methods of testing, and the results so that the results can be built upon.
2. Define the terms hypothesis, theory, and law.
A hypothesis is an educated guess based on observations. It must make a prediction(s) and it must be falsifiable (disprovable). A hypothesis cannot be proven to be true.
A theory is a hypothesis or related group of hypotheses that have been supported by repeated testing.
A law explains a body of observations where no exceptions have been found to the rule that it states. A law is generally able to be stated as a mathematical equation.
3. What are the common characteristics of all living things?
Living things are organized and complex.
Living things grow and reproduce.
Living things respond to stimuli.
Living things acquire and use material and energy.
Living things use DNA to store information.
4. Describe the levels of organization of life beginning with the smallest living unit and progressing up in complexity to ecosystems.
Cells: the smallest living unit. They are enclosed by a plasma membrane, use DNA as a hereditary blueprint, and obtain energy and nutrients from their environment.
Tissues: made up of multiple cells with a shared purpose
Organs: Structures made up of multiple types of tissues unified for a common purpose
Organ Systems: Systems made up of multiple organs unified for a common purpose
Organism: A living being made up of multiple organ systems working in unison
Population: All organisms of a single species living in a geographic area
Community: All of the populations in a given geographic area
Ecosystem: The biological community plus all of the abiotic factors (weather, soil type, etc) in a given geographic area
5. Compare and contrast DNA and RNA.
DNA and RNA are both nucleotides made up of a 5 carbon sugar, a phosphate group, and a Nitrogen containing base. The polymers of both are built by the bonding of the sugar of one nucleotide to the phosphate group of the next, and both play a role in the building of proteins.
DNA differs from RNA in several ways. The sugar found DNA is deoxyribose rather than the ribose found in RNA. DNA carries the genetic information needed for protein construction whereas RNA is directly involved in protein construction. DNA and RNA share three of their four bases. Both have adenine (A), guanine (G), and cytosine (C). The fourth base of DNA is thymine (T) whereas the fourth base in RNA is uracil (U). Each DNA molecule consists of two chains of nucleotides forming a double helix held together by hydrogen bonds. RNA consists of a single strand of nucleotides. There is only a single type of DNA and there are 3 types of RNA (mRNA, tRNA, rRNA) each with a specific function in protein synthesis.
6. Describe the 3 types of molecular bonds. Which is strongest and which is weakest?
The strongest of the molecular bonds is the covalent bond. Covalent bonds are formed by the sharing of outer valence electrons. Two electrons (one from each atom) are shared in a covalent bond. Covalent bonds can share electrons evenly in nonpolar bonds when the nuclei are of similar size or unequally in polar bonds when the nuclei are of very different sizes. Covalent bonds may share also share 4 (2 each) electrons in a double bond or 6 (3 each) in a triple bond. Most biological molecules contain covalent bonds.
Ionic bonds are formed by the electromagnetic attraction of oppositely charged ions. One atom loses one or more electrons creating a positive charge (+1 per electron lost) and emptying its outer valence. The other atom gains one or more electrons creating a negative charge (-1 per electron gained) filling its outer valence. The opposite charges of these ions attract one another binding them together in an ionic bond.
Hydrogen bonds are by far the weakest of the three molecular bonds, though when many of them act in concert the combined effect can be stronger than a single ionic bond. Hydrogen bonds are formed by the weak electromagnetic attraction between the positive end of one polar molecule to the negative end of another polar molecule, for example the weakly negatively charged oxygen end of a water molecule is attracted to one of the weakly positively charged hydrogen ends of another water molecule.
7. What properties of water make it important for life? Briefly describe each of these properties.
Slides 27-39 Ch01-04 Review presentation
8. How are biological molecules formed? How are they broken down?
Slides 47-49 Ch01-04 Review presentation
9. What is a plasma membrane? What is it composed of? What functions does it serve?
Slides 92-101 Ch01-04 Review presentation
10. Define diffusion and osmosis.
Slides 102-106 and 114 Ch01-04 Review presentation
11. Compare and contrast prokaryotic and eukaryotic cells.
Slides 136-143 Ch01-04 Review presentation
12. Define Energy, Chemical Energy, and Work.
Energy is the capacity to do work.
· Synthesizing molecules
· Moving objects
· Generating heat and light
Chemical energy is the energy that powers life
· The objects that move are electrons, which reposition during chemical reactions
Work is force acting over distance.
· Change in kinetic energy
13. What are the First and Second Laws of Thermodynamics and how do they impact growing complexity and decreasing entropy in living things?
Slides 5-8 Ch05-07 Review presentation
The earth is not a closed system. Solar energy is continuously being added to the earth. Without this continuous addition of energy the growing complexity and decreasing entropy in living things would not be possible.
14. Describe the process of photosynthesis. What is happening at a molecular and atomic level?
Slides 48-55, 74-76 Ch05-07 Review presentation
15. Compare and contrast exergonic and endergonic reactions and explain how they are related in coupled reactions.
Slides 9-20, 24-25 Ch05-07 Review presentation
16. Detail two coupled reactions involving ATP.
Slides 22-26 Ch05-07 Review presentation
17. What are enzymes and how do they function?
Slides 31-41 Ch05-07 Review presentation
18. What environmental factors effect enzyme function? How do they effect enzyme function?
Slides 46-47 Ch05-07 Review presentation
19. How does photosynthesis convert solar energy into energy usable by cells? Be specific. What are the chemical reactions?
Slides 48-55, 74-76 Ch05-07 Review presentation
20. What role does the color of photosynthetic pigments play in photosynthesis?
Slides 56-59 Slides 48-55, 74-76 Ch05-07 Review presentation
21. Compare and contrast photosynthesis and cellular respiration. Again be specific about reactions energy requirements etc.
Slides 52-56 and slides 87-94 Slides 48-55, 74-76 Ch05-07 Review presentation
22. How is cellular energy stored?
Slides 86-88 Slides 48-55, 74-76 Ch05-07 Review presentation
23. Compare and contrast cellular respiration and fermentation. Once again be specific. What chemical processes are occurring in each and how are those similar and/or different?
Slides 100-105 and slides 110-115 Slides 48-55, 74-76 Ch05-07 Review presentation
24. Describe the structure of DNA. Be sure to include what forms the skeleton and how are the strands held together?
Slides 3-5 and 74-78 Ch08-11 Review presentation
25. Compare and contrast chromosomes, chromatids, genes, and alleles.
Genes are segments of DNA that code for making one or more proteins. Each gene begins with a start codon that also signals the addition of methionene and ends with one of three stop codons.
Alleles are specific genes. Example: a gene may be responsible for fur color and alleles for that gene may code for brown or white color. There can be dozens of alleles for any particular gene.
Chromosomes are structures composed of DNA and proteins that contain multiple genes.
Chromatids are duplicated chromosomes connected by a centromere in preparation for mitosis.
26. Compare and contrast prokaryotic and eukaryotic cell division.
Slides 10-15, 20-23, and 27-33 Ch08-11 Review presentation
27. Compare and contrast mitosis and meiosis.
Slides 27-33 and 35-42 Ch08-11 Review presentation
28. Without genetic testing how could you determine if an organism is homozygous or heterozygous for a specific trait (ie hair color)?
If the individual expresses the recessive phenotype then it is certain that they are homozygous for the recessive character. If the individual expresses the dominant character you would need to look at the phenotypes of the previous and following generations. If one of the parents expresses the recessive phenotype then you can be certain that the individual is heterozygous. If any of the individuals children express the recessive character then you can be certain that the individual is heterozygous for the character. If both parents and all children express the dominant character then it is likely that the individual is homozygous, though you cannot be certain without genetic testing.
29. Describe three ways that genetic variability is increased.
Slides 39-42 Ch08-11 Review presentation
30. Two fruitflies are bred. One is true breeding for red eyes and one is true breeding for white eyes. Red eyes are dominant.
· What will the genotype and phenotype of the offspring be?
R / Rr / R / r / R / r
r / R / r / R / r
The genotype of all offspring will be heterozygous and all will express the dominant phenotype of red eyes.
· If two of the offspring of the above match are crossbred what will the genotype and phenotype of their offspring be?
R / rR / R / R / r / R
r / R / r / r / r
The genotypes of the offspring will be 1 homozygous dominant, 2 heterozygous, and one homozygous recessive. The phenotypic ration will be 3 dominant (red) to 1 recessive (white).
· How would the genotypes and phenotypes be different if red eye color was partially dominant producing pink eyes when heterozygous?
If red eye color was partially dominant then the 2 heterozygous offspring would have pink eyes rather than red eyes.
· If the red-eyed fruitfly has straight wings and the white-eyed fruitfly has wrinkled wings. (Straight wings are dominant.) What would the genotype and phenotype of the offspring be?
Parents: RRSS x rrss
R / S / R / S / R / S / R / Srs / Rr / Ss / Rr / Ss / Rr / Ss / Rr / Ss
rs / Rr / Ss / Rr / Ss / Rr / Ss / Rr / Ss
rs / Rr / Ss / Rr / Ss / Rr / Ss / Rr / Ss
rs / Rr / Ss / Rr / Ss / Rr / Ss / Rr / Ss
All offspring will be heterozygous for both traits and will express the dominant phenotype for both traits.
If the heterozygous offspring are crossed the results will be as follows:
Parents: RrSs x RrSs
R / S / R / s / r / S / r / sRS / RR / SS / RR / Ss / Rr / SS / Rr / Ss
Rs / RR / Ss / RR / ss / Rr / Ss / Rr / ss
rS / Rr / SS / Rr / Ss / rr / SS / rr / Ss
rs / Rr / Ss / Rr / ss / rr / Ss / rr / ss
The genotypic ratio can be read from the Punnet square. The phenotypic ratio will be 9:3:3:1 red/straight, red/wrinkled, white/straight, white/wrinkled.
31. Describe the process of DNA replication. What is meant by semiconservative replication? How are continuous synthesis and discontinuous synthesis involved in the process?
Slides 78-90 Ch08-11 Review presentation
32. Compare and contrast DNA and RNA.
DNA and RNA are both nucleotides made up of a 5 carbon sugar, a phosphate group, and a Nitrogen containing base. The polymers of both are built by the bonding of the sugar of one nucleotide to the phosphate group of the next, and both play a role in the building of proteins.
DNA differs from RNA in several ways. The sugar found DNA is deoxyribose rather than the ribose found in RNA. DNA carries the genetic information needed for protein construction whereas RNA is directly involved in protein construction. DNA and RNA share three of their four bases. Both have adenine (A), guanine (G), and cytosine (C). The fourth base of DNA is thymine (T) whereas the fourth base in RNA is uracil (U). Each DNA molecule consists of two chains of nucleotides forming a double helix held together by hydrogen bonds. RNA consists of a single strand of nucleotides. There is only a single type of DNA and there are 3 types of RNA (mRNA, tRNA, rRNA) each with a specific function in protein synthesis.