Cellular Respiration and Photosynthesis, Exams of Biology

Download Cellular Respiration and Photosynthesis and more Exams Biology in PDF only on Docsity! UA BSC 108 Exam 2 Verified 2024 1. How does asexual reproduction differ from sexual reproduction? - ANSWER-Asexual Reproduction involves one parent and produces offspring that are genetically identical to each other and to the parent. Sexual Reproduction involves two parents and produces offspring that are genetically unique. 1. What are alleles? - ANSWER-one of two alternate forms of gene that can have the same locus on homologous chromosomes and are responsible for alternative traits 1. What is the difference between aerobic and anaerobic respiration? - ANSWER- Aerobic respiration can only occur in the presence of oxygen, during aerobic respiration the reactants oxygen and glucose are turned into products carbon dioxide, water, and ATP. Anaerobic respiration occurs when oxygen is not present, occurs in two steps. Glycolysis produces ATP from the reactant glucose then fermentation created the lactic acid, or ethanol, depending on the type of fermentation. 10. Can a woman and a man both with Type A blood have a baby with Type O blood? Explain your answer. - ANSWER-A person with the blood type A can have one of two genotypes: AA, or AO. If the person has genotype AA it would be impossible for them to have a child with blood type O. If the person has genotype AO there would be a 50% chance of passing on the O allele. The father would also have to pass on an O allele for the child to have blood type O 10. The third stage of cellular respiration is electron transport. Where in the cell does electron transport take place? - ANSWER-inner membrane 10. What is meiosis? - ANSWER-a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cells 11. How does meiosis I differ from meiosis II? - ANSWER-In meiosis II chromosomes are further separated into sister chromatids. Meiosis I include crossing over or recombination of genetic material between chromosome pairs, while meiosis II does not 11. List the inputs and outputs of electron transport. - ANSWER-"Input- 10 NADH + H+, 2 FADH2 Output- 10 NAD+, 2FAD, H2O, 34 ATP" 11. What is pleiotropy? - ANSWER-when one gene influences two or more seemingly unrelated phenotypic traits. 12. Is oxygen required for electron transport? - ANSWER-yes 12. List three ways in which meiosis differs from mitosis. - ANSWER-Mitosis consists of one stage whereas meiosis consists of two stages. Mitosis produces diploid cells (46 chromosomes) whereas meiosis produces haploid cells (23 chromosomes). Mitosis produces two identical daughter cells whereas meiosis produces four genetically different daughter cells. 13. List three origins of genetic variation. - ANSWER-"a. Independent assortment of chromosomes b. Crossing Over c. Random Fertilization" 13. Which stage of cellular respiration generates the most ATP? - ANSWER-Electron Transport Chain 14. Describe fermentation in human muscle cells. - ANSWER-Under strenuous conditions, muscles spend ATP faster than the bloodstream can deliver O2, when this happen the muscles begin to work anaerobically. After around 15 second muscle cells begin to generate ATP by the fermentation process 14. How does crossing over contribute to genetic diversity? - ANSWER-by combining DNA from two parents into a single chromosome 15. What is nondisjunction? - ANSWER-An error in cell division that causes homologous chromosomes or sister chromatids to move to the same side of the dividing cell 2. Define homozygous and heterozygous. - ANSWER-"1) Homozygous- having identical alleles at corresponding chromosomal loci 2) Heterozygous- having two different alleles for a trait" 2. How do autotrophs differ from heterotrophs? - ANSWER-autotrophs make their own energy, heterotrophs must consume other organisms to get their energy 2. What are the two main phases of the eukaryotic cell cycle? - ANSWER-"a. Interphase b. Mitotic phase" 3. During which phase of the cell cycle does DNA duplicate? - ANSWER-interphase- chromosome duplication 3. State the law of segregation. - ANSWER-members of a pair of homologous chromosomes separate during the formation of gametes and are distributed to different gametes so that every gamete receives only one member of the pair 3. What is the function cellular respiration? - ANSWER-provides cells with energy they need to function 4. Contrast genotype and phenotype. - ANSWER-genotype is the genetic makeup of an organism. Phenotype is what an organism looks like as a consequence of its genotype photosystem then replaces the lost electrons by extracting new ones from water. This is the step that releases O2 during photosynthesis. 2. Energized electrons from the first photosystem pass down an electron transport chain to the second photosystem. The chloroplast uses the energy released by this electron "fall" to make ATP. 3. The second photosystem transfers its light-excited electrons to NADP+, reducing it to NADPH. List all products of the light reactions. carbon dioxide, water. Glucose, oxygen How and where does water enter a plant? - ANSWER-Water enters root hair cells by osmosis. List all products in the Calvin cycle. - ANSWER-"6 Turns of the Calvin Cycle→ 1 C₆H₁₂O₆ 6CO₂ → 1 C₆H₁₂O₆ 18 ATP + 12 NADPH → 1 C₆H₁₂O₆ Left over ATP is used elsewhere by the cell. " The Calvin cycle has three main stages. Name the stages and summarize the events of each stage. - ANSWER-"1) Carbon Fixation- The enzyme rubisco combines CO2 with 5-carbon sugar rubulose biphosphate (RuBP). The unstable product formed splits into 2 molecules of 3-carbon 3-phosphoglyceric acid (3-PGA). 2) Reduction- Energy from 6 molecules of ATP is used to oxidize NADPH to NADP+. Six molecules of 3-PGA are reduced, producing six molecules of energy-rich 3-carbon sugar G3P. 3) Release of one molecule of G3P- Five of the previously created G3Ps remain in the cycle, but one molecule is released. 4) Regeneration of RuBP - series of chemical reactions uses energy from ATP to rearrange the atoms of the 5 G3P molecules, (15 total carbons), which forms 3 RuBP molecules (15 total carbons). These will start another turn of the cycle. " What are the membranes inside chloroplasts called? - ANSWER-inner and outer membranes What environmental factor is C4 photosynthesis an adaptation for? - ANSWER-High levels of CO2 and drought environments Contrast carbon fixation in C4 and CAM plants. C4 plants initially attach CO2toPEP to form the four-carbon compound OAA using the enzyme PEP carboxylase. This takes place in the loosely packed cells called mesophyll cells. OAA is then pumped to another set of cells, the bundle sheath cells, which surround the leaf vein. There, it releases the CO2for use by Rubisco. By concentrating CO2in the bundle sheath cells, C4plants promote the efficient operation of the Calvin-Benson cycle and minimize photorespiration. CAM plants also initially attach CO2to PEP and form OAA. However, instead of fixing carbon during the day and pumping the OAA to other cells, CAM plants fix carbon at night and store the OAA in large vacuoles within the cell. This allows them to have their stomates open in the cool of the evening, avoiding water loss, and to use the CO2 for the Calvin-Benson cycle during the day, when it can be driven by the sun's energy. What is a photosynthetic autotroph? - ANSWER-An organism that makes its own food from inorganic ingredients. What is polygenic inheritance? - ANSWER-inheritance pattern of a trait controlled by two or more genes, genes may be the same of different chromosomes What is the fluid inside chloroplasts called? - ANSWER-Stroma What is the primary function of pigments in photosynthesis? Name the primary pigment used in photosynthesis. - ANSWER-Pigments absorb certain wavelengths. They are the means by which the energy of sunlight is captured for photosynthesis. The primary pigment used in photosynthesis is Chlorophylla-a. Why are leaves green? - ANSWER-Their green color is from chlorophyll, a pigment (light- absorbing molecule) in the chloroplasts that plays a central role in converting solar energy to chemical energy. Write the overall equation for photosynthesis. - ANSWER- 6CO2+6H2O→C6H12O6+6O2