Genetics - Analysis and Principles

Biology

Quiz 3 :

Chromosome Transmission During Cell Division and Sexual Reproduction

Quiz 3 :

Chromosome Transmission During Cell Division and Sexual Reproduction

Question Type
search
arrow
A cell is diploid and contains three chromosomes per set. Draw the arrangement of chromosomes during metaphase of mitosis and metaphase of meiosis I and II. In your drawing, make one set dark and the other lighter.
Free
Essay
Answer:

Answer:

A diploid cell with three sets of chromosomes will be as follows in its three different metaphase stages of cell cycle:
1. Metaphase of mitosis: In this event, chromosomes containing sister chromatids are attached to the spindle microtubules raised from both the poles of the cell. The entire sister chromatids will align at metaphase plate, in order to get separated as two chromatids during anaphase.
img Metaphase of mitosis
2. Metaphase of meiosis I : In this event, tetrads of chromosomes are aligned on the metaphase plate and each pair of chromatids is attached only to single pole via the spindle microtubule. During this phase, synapsis occurs and crossing over takes place between the two sets of chromosomes.
img Metaphase of meiosis I
3. Metaphase of meiosis II: While reaching metaphse II, synapsis completes and crossing over takes place between the two sets of chromosomes. In addition, only half number of the chromosomes will remain, as one cell division has taken place soon after meiosis I. The resulting sister chromatids will align across the metaphase, with their kinetochores being attached to both the oles of the spindle via microtubules. (similar to metaphase of mitosis).
img Metaphase of meiosis II

Tags
Choose question tag
close menu
arrow
For the following events, specify whether they occur during mitosis, meiosis I, or meiosis II: A. Separation of conjoined chromatids within a pair of sister chromatids B. Pairing of homologous chromosomes C. Alignment of chromatids along the metaphase plate D. Attachment of sister chromatids to both poles
Free
Essay
Answer:

Answer:

img img img img img img img img img img img img img img img img img img img

Tags
Choose question tag
close menu
arrow
When studying living cells in a laboratory, researchers sometimes use drugs as a way to cause cells to remain in a particular phase of the cell cycle. For example, aphidicolin inhibits DNA synthesis in eukaryotic cells and causes them to remain in the G 1 phase because they cannot replicate their DNA. In what phase of the cell cycle-G 1 , S, G 2 , prophase, metaphase, anaphase, or telophase-would you expect somatic cells to stay if the following types of drug were added A. A drug that inhibits microtubule formation B. A drug that allows microtubules to form but prevents them from shortening C. A drug that inhibits cytokinesis D. A drug that prevents chromosomal condensation
Free
Essay
Answer:

Answer:

A drug named aphidicolin inhibits deoxyribonucleic acid synthesis
img in eukaryotic cells. It is observed that this drug causes DNA to remain in their G 1 phase, so that DNA replication may stop.
If such type of drug is administered, then several changes takes place in G 1 , S, G 2 , prophase, metaphase, anaphase, or telophase of cell cycle. The changes observed in somatic cells when following types of drugs are administered are as follows:
A drug inhibits microtubule formation- In this case drug will affect G 2 phase of the cell cycle that is it could not complete its prophasE.A drug that allows microtubules to form but prevents them from shortening- In this case metaphase is affected and the cell may possibly not enter anaphasE.A drug that inhibits cytokinesis- In this case, cell could not divide into two daughter cells, that is telophase is affecteD.A drug that prevents chromosomal condensation- In this case cell's G 2 phase is affected and it could not enter prophasE.

Tags
Choose question tag
close menu
arrow
With regard to sister chromatids, which phase of mitosis is the organization phase, and which is the separation phase
Essay
Answer:
Tags
Choose question tag
close menu
arrow
What is a homolog With regard to genes and alleles, how are homologs similar to and different from each other
Essay
Answer:
Tags
Choose question tag
close menu
arrow
In Figure 3.19, Morgan obtained a white-eyed male fly in a population containing many red-eyed flies that he thought were true-breeding. As mentioned in the experiment, he crossed this fly with several red-eyed sisters, and all the offspring had red eyes. But actually this is not quite true. Morgan observed 1237 red-eyed flies and 3 white-eyed males. Provide two or more explanations why he obtained 3 white-eyed males in the F 1 generation.
Essay
Answer:
Tags
Choose question tag
close menu
arrow
How would you set up crosses to determine if a gene was Y linked versus X linked
Essay
Answer:
Tags
Choose question tag
close menu
arrow
Occasionally during meiosis, a mistake can happen whereby a gamete may receive zero or two sex chromosomes rather than one. Calvin Bridges made a cross between white-eyed female flies and red-eyed male flies. As you would expect, most of the offspring were red-eyed females and white-eyed males. On rare occasions, however, he found a white-eyed female or a red-eyed male. These rare flies were not due to new gene mutations, but instead were due to mistakes during meiosis in the parent flies. Consider the mechanism of sex determination in fruit flies and propose how this could happen. In your answer, describe the sex chromosome composition of these rare flies.
Essay
Answer:
Tags
Choose question tag
close menu
arrow
In Morgan's experiments, which result do you think is the most convincing piece of evidence pointing to X-linkage of the eye color gene Explain your answer.
Essay
Answer:
Tags
Choose question tag
close menu
arrow
What is a sister chromatid Are sister chromatids genetically similar or identical Explain.
Essay
Answer:
Tags
Choose question tag
close menu
arrow
How does the attachment of kinetochore microtubules to the kinetochore differ in metaphase of meiosis I from metaphase of mitosis Discuss what you think would happen if a sister chromatid was not attached to a kinetochore microtubule.
Essay
Answer:
Tags
Choose question tag
close menu
arrow
With regard to thickness and length, what do you think the chromosomes would look like if you microscopically examined them during interphase How would that compare with their appearance during metaphase
Essay
Answer:
Tags
Choose question tag
close menu
arrow
White-eyed flies have a lower survival rate than red-eyed flies. Based on the data in Figure 3.18, what percentage of white-eyed flies survived compared with red-eyed flies, assuming 100% survival of red-eyed flies FIGURE 3.18 Inheritance pattern of an X-linked trait in fruit flies. img
Essay
Answer:
Tags
Choose question tag
close menu
arrow
The process of binary fission begins with a single mother cell and ends with two daughter cells. Would you expect the mother and daughter cells to be genetically identical Explain why or why not.
Essay
Answer:
Tags
Choose question tag
close menu
arrow
In his original studies of Figure 3.18, Morgan first suggested that the original white-eyed male had two copies of the white-eye allele. In this problem, let's assume that he meant the fly was X w Y w instead of X w Y. Are his data in Figure 3.18 consistent with this hypothesis What crosses would need to be made to rule out the possibility that the Y chromosome carries a copy of the eye color gene FIGURE 3.18 Inheritance pattern of an X-linked trait in fruit flies. img
Essay
Answer:
Tags
Choose question tag
close menu
arrow
Describe the key events during meiosis that result in a 50% reduction in the amount of genetic material per cell.
Essay
Answer:
Tags
Choose question tag
close menu
arrow
Discuss the principles of the chromosome theory of inheritance. Which principles were deduced via light microscopy, and which were deduced from crosses What modern techniques could be used to support the chromosome theory of inheritance
Essay
Answer:
Tags
Choose question tag
close menu
arrow
A species is diploid and has three chromosomes per set. Draw what the chromosomes would look like in the G 1 and G 2 phases of the cell cycle.
Essay
Answer:
Tags
Choose question tag
close menu
arrow
A diploid eukaryotic cell has 10 chromosomes (5 per set). As a group, take turns having one student draw the cell as it would look during a phase of mitosis, meiosis I, or meiosis II; then have the other students guess which phase it is.
Essay
Answer:
Tags
Choose question tag
close menu
arrow
Let's suppose that you have karyotyped a female fruit fly with red eyes and found that it has three X chromosomes instead of the normal two. Although you do not know its parents, you do know that this fly came from a mixed culture of flies in which some had red eyes, some had white eyes, and some had eosin eyes. Eosin is an allele of the same gene that has white and red alleles. Eosin is a pale orange color. The red allele is dominant and the white allele is recessive. The expression of the eosin allele, however, depends on the number of copies of the allele. When females have two copies of this allele, they have eosin eyes. When females are heterozygous for the eosin allele and white allele, they have light-eosin eyes. When females are heterozygous for the red allele and the eosin allele, they have red eyes. Males that have a single copy of eosin allele have light-eosin eyes. You cross this female with a white-eyed male and count the number of offspring. You may assume that this unusual female makes half of its gametes with one X chromosome and half of its gametes with two X chromosomes. The following results were obtained: img * A female offspring can be XXX, XX, or XXY. Explain the 3:1 ratio between female and male offspring. What was the genotype of the original mother, which had red eyes and three X chromosomes Construct a Punnett square that is consistent with these data.
Essay
Answer:
Tags
Choose question tag
close menu
Showing 1 - 20 of 46