Exam 8: The Cellular Basis of Reproduction and Inheritance

Which of the following statements regarding mitosis and meiosis is false?

If a chromosome fragment breaks off and then reattaches to the original chromosome but in the reverse direction, the resulting chromosomal abnormality is called a(n)

Plants grow taller through mitosis at the tips of their shoots (above ground) and at the tips of their roots (below ground). Here are two samples of tissue taken from a grass plant, one from the tip of the root and one from the mid part of the plant. Stage Sample 1 Sample 2 Interphase 74\% 98\% Prophase 18\% 0.5 Metaphase 4\% 0.2\% Anaphase 2\% 0.1\% Telophase 1\% 0.1\% -From the data shown what can you conclude about the amount of time these plant cells spend in various stages of the cell cycle?

You are observing a single cell under a microscope. You go home for the night, and the next day you see four cells. The four cells look similar, and when you stain them with a dye that binds to DNA they all appear to contain the same amount of DNA as the original cell. What likely happened overnight?

During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles?

Which of the following statements regarding cell division is false?

Which of the following features likely accounts for the difference between plant and animal cell cytokinesis?

Independent orientation of chromosomes at metaphase I results in an increase in the number of

A technique called flow cytometry is used by scientists and researchers to count or sort cells based on specific properties. By labeling cellular DNA with a fluorescent dye, flow cytometry can sort cells based on the amount of DNA present, thereby making it possible to distinguish between cells that are in different stages of the cell cycle. Flow cytometry is especially useful to the medical community because it can help with the diagnosis of certain types of cancers. Below is a typical set of data that you might obtain when running a flow cytometry experiment using a sample of healthy skin cells. Use this figure to help you answer the following questions. After reading the paragraph below, answer the questions that follow. -Which peak represents cells that contain the most DNA?

Cancer is not usually inherited because

When animal cells are grown in a petri dish, they typically stop dividing once they have formed a single, unbroken layer on the bottom of the dish. This arrest of division is an example of

Source: Adapted from C. A. Huether et al., Maternal age specific risk rate estimates for Down syndrome among live births in whites and other races from Ohio and Metropolitan Atlanta, 1970-1989, Journal of Medical Genetics 35: 482-90 (1998). Figure 8.20B Maternal age and incidence of Down syndrome -Many cancer drugs known as "antimitotics" target microtubules. What is the first stage of mitosis at which these drugs are likely to have an effect?

Mr. and Mrs. Smith have three sons in elementary school. Two of their children are progressing normally, but their youngest son, Charles, has been much slower than his siblings in developing speech and language skills. His parents are concerned that he has a learning disability and decide to investigate further. Since some learning disabilities can be genetically based, their pediatrician recommends a chromosomal analysis. The results show that Charles has a trisomy of the sex chromosomes, diagnosed as XYY. A mistake during sperm formation resulted in an extra copy of the Y chromosome. The extra copy was passed on to Charles during fertilization. Most often, this chromosomal change causes no unusual physical features or medical problems, but those with trisomy of the sex chromosomes may have a higher-than-normal risk of delays in learning development. -During which stage of meiosis could this mistake have occurred?

Which of the following statements regarding Down syndrome is false?

A technique called flow cytometry is used by scientists and researchers to count or sort cells based on specific properties. By labeling cellular DNA with a fluorescent dye, flow cytometry can sort cells based on the amount of DNA present, thereby making it possible to distinguish between cells that are in different stages of the cell cycle. Flow cytometry is especially useful to the medical community because it can help with the diagnosis of certain types of cancers. Below is a typical set of data that you might obtain when running a flow cytometry experiment using a sample of healthy skin cells. Use this figure to help you answer the following questions. After reading the paragraph below, answer the questions that follow. -If you used flow cytometry to sort a sample of cancerous cells that have been treated with a drug to prevent them from replicating their DNA, what peaks would you expect to see on the resulting flow cytometry data set?

Source: Adapted from C. A. Huether et al., Maternal age specific risk rate estimates for Down syndrome among live births in whites and other races from Ohio and Metropolitan Atlanta, 1970-1989, Journal of Medical Genetics 35: 482-90 (1998). Figure 8.20B Maternal age and incidence of Down syndrome -You see a cell with several nuclei and you know that something is different about cell division. What is the most likely explanation?

The genetic material is duplicated during

Eukaryotic cells spend most of their cell cycle in which phase?

Which of the following statements regarding the function of mitosis is false?

A cell that has a cell wall is undergoing cell division, and the following events are observed: the formation of a cell plate and the division of the cell into two daughter cells. What type of cell is being observed and what process(es) is it going through?