Concept explainers
Videos
Introduction :
During cell division, the chromosomes separate and one of each of thesister chromatids going to opposite poles of the cell. As a result, eachnew cell has the correct number of chromosomes. Sometimes sister chromatids fail to separate properly during cell division. This condition is called nondisjunction. As a result of nondisjunction, the gametes will not have correct number of chromosomes. When one of these gametes fertilizes another gamete,the resulting offspring will not have the correct number of chromosomes.
Answer to Problem 25A
Correct answer :
The correct answer is option (C) The sister chromatids do not separate.
Explanation of Solution
Explanation/justification for the correct answer :
Option (C) Nondisjunction is a condition that occurs when the sister chromatids fail to separate during meiosis I or meiosis II. This result in incorrect number of chromosomes in the gametes. Thus, the correct answer is option (C).
The explanation for the incorrect answer :
Option (A). Cytokinesis does not occur properly. Cytokinesis is the division of cytoplasm. Division of cytoplasm is not associated with nondisjunction. Thus, this is an incorrect answer.
Option (B). The nucleoli do not disappear. The nucleoli and nuclear membrane disappear during prophase of cell division. Thus, this is an incorrect option.
Option (D). The chromosome do not condense properly. The condensation of chromosome does cause nondisjunction of chromosomes. Thus, this is an incorrect answer.
During cell division, the chromosomes separate and one of each of thesister chromatids going to opposite poles of the cell. As a result, eachnew cell has the correct number of chromosomes.Sometimes sister chromatids fail to separate properly during cell division. This condition is called nondisjunction. As a result of nondisjunction,the gametes will not have correct number of chromosomes. When one of these gametes fertilizes another gamete,the resulting offspring will not have the correct number of chromosomes.
Notice that nondisjunction can result in extra copies of a certain chromosome or only one copy of a particular chromosome in the
offspring. Having a set of three chromosomes of one kind is called trisomy. Having only one of a particular type of chromosome is called monosomy. Nondisjunction can occur in any organism in which gametes are produced through meiosis. In humans, alterations of chromosome number are associated with serious human disorders, which often are fatal.
Chapter 11 Solutions
Glencoe Biology, Florida Edition
Additional Science Textbook Solutions
Campbell Essential Biology (7th Edition)
Brock Biology of Microorganisms (15th Edition)
Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th Edition)
Organic Chemistry (8th Edition)
Microbiology: An Introduction
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
- Draw a rough sketch of the control and experimental data using a normal dose/response curve plot: i.e. % of total bound ligand vs. concentration. Indicate Kd and Bmax on this sketch. You don’t need to use exact numbers, but the relative proportions should be closearrow_forwardName something that could be happening to glutamate transporters that could have this effect on glutamate transport (i.e. the difference in glutamate transporters between control and experimental conditions). (Bonus: if you can also guess what the experimental condition is).arrow_forwarda. For the control condition, calculate Kd. Include units and show your work. b. For the control condition, calculate Bmax. Include units and show your work. c. For the experimental condition, calculate Kd. Include units and show your work. For the experimental condition, calculate Bmax. Include units and show your work.arrow_forward
- Now draw a rough sketch of what the control data might look like if in addition to the specific binding, there was also a considerable amount of nonspecific binding (again using a normal dose/response curve)arrow_forwarda. Which drug is the most potent? a,b,c,d,e b. Which drug has the highest efficacy?arrow_forwardThe shape of radishes may be long (SL/SL), oval (SL/SS), or round (SS/SS), and the color of radishes may be red (CR/CR), purple (CR/CW) or white (CW/CW). If a long, red radish plant is crossed with a round, white plant, what will be the appearance of the F1 and F2 generations?arrow_forward
- Nonearrow_forwardQuestion #3: In the KeyGene paper, the authors state that it would be useful if pollen from an apomict would transmit apomixis-inducing genes to the female in the cross (assuming the pollen is viable). Assuming there was just one gene conferring gametophytic obligate apomixis, and that the two parents are inbreds, what would be the consequences of such a cross if: a) The apomixis was a dominant trait? Indicate the genotypes and phenotypes (apomict or non- apomict) of the parents, F1 and F2 generations. Remember to include the expected genotypic and phenotypic ratios (or percentages) in the F1 and F2 generations, and to position the female first (left side) in the parental cross. b) The apomixis was a recessive trait? Indicate the genotypes and phenotypes (apomict or non- apomict) of the parents, F1 and F2 generations. Remember to include the expected genotypic and phenotypic ratios (or percentages) in the F1 and F2 generations, and to position the female first (left side) in the…arrow_forwardQuestion #5: Assume that two genes are identified that confer gametophytic facultative apomixis in soybean. The genes show independent assortment. Recessive alleles at both loci are required for the facultative apomixis. Facultative apomixis is triggered when the temperature at pollination is above 20 degrees C. At temperatures below 20 degrees C, all reproduction is sexual, independent of genotype. A facultative apomict male, capable of producing viable pollen, was crossed with a sexually reproducing female. Assuming the parents are completely inbred, what are the predicted phenotypic ratios (apomict: non-apomict) for the F1, F2, and DH (F1-derived) generations at each of the following temperatures*: a) 15°C? b) 25°C? *for full credit, show crosses and genotypes where appropriate. Remember to position the female first (left side) in the cross. Type your answer here:arrow_forward
- a. What percentage of a drug is eliminated after 4 half-lives? Please round to the nearest percent. b. What will happen to elimination of the drug in the previous question if the system is saturated? explain and show any math involvedarrow_forwardIf you wanted to reduce the difference between peak and trough levels that occur with repeated administration of a drug, how would you adjust the dose and dose interval without changing the plateau concentration (plateau is the average of peak and trough levels)? Select your answers for both dose and interval. Hint: It may be helpful to think about this problem using an example such as food. How would you eat if you wanted to maintain very steady hunger/satiety levels without changing your total caloric intake? Options: A. Dose; Increase dose B. Dose; Decrease dose C. Dose; Do not change dose D. Interval; Increase the interval between doses (give the drug less frequently) E. Interval; Decrease the interval between doses (give the drug more frequently) F. Interval; Do not change the intervalarrow_forwardWhat percentage of a drug is eliminated after 4 half-lives? Please round to the nearest percent. Show the matharrow_forward
Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSON
Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax
Anatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education