FiltersDone

Question type

Essay

Multiple Choice

Short Answer

True False

Matching

Exam 9: The Cell Cycle

Show Answer

Share

---

All types

Filters

Study FlashcardsPractice ExamLearn

Question 21

Multiple Choice

Review LaterAdd Note

Review Later

Density-dependent inhibition is explained by which of the following?

A) As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce growth factors.
B) As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor.
C) As cells become more numerous, the cell surface proteins of adjacent cells bind to each other and send signals that inhibit cell division.
D) As cells become more numerous, the level of waste products increases, eventually slowing down metabolism.

E) B) and C)
F) None of the above

Correct Answer

verified

Show Answer

Question 22

Multiple Choice

Review LaterAdd Note

Review Later

Which of the following is true concerning cancer cells?

A) They exhibit density-dependent inhibition when growing in culture.
B) They must be attached to a substrate to divide in culture.
C) They evade the normal controls that trigger programmed cell death.
D) They stop dividing in culture when growth factors are depleted.

E) B) and D)
F) B) and C)

Correct Answer

verified

Show Answer

Question 23

Multiple Choice

Review LaterAdd Note

Diatoms and some yeasts are unicellular eukaryotes that have mechanisms of nuclear division that may resemble intermediate steps in the evolution of mitosis. Which of the following is a characteristic feature of nuclear division in these organisms?

Where are the motor proteins that move chromosomes toward the poles of the mitotic spindle located?

The cell cycle is regulated at the molecular level by a set of proteins known as

The beginning of anaphase is indicated by which of the following?

Figure 9.3 -In Figure 9.3, which number represents the point in the cell cycle during which the chromosomes are replicated?

What is a cleavage furrow?

Besides the ability of some cancer cells to divide uncontrollably, what else could logically result in a tumor?

A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. How many picograms would be found at the end of S and the end of G2?

A cell in G2 of the cell division cycle contains 20 chromatids. How many centromeres are present in this cell?

Figure 9.3 -In Figure 9.3, which of the numbered regions would contain cells at metaphase?

Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells?

Cells from advanced malignant tumors frequently have very abnormal chromosomes as well as an abnormal number of chromosomes. What might explain the association between malignant tumors and chromosomal abnormalities?

Figure 9.3 -In Figure 9.3, G1 is represented by which numbered parts of the cycle?

Figure 9.3 -In Figure 9.3, DNA synthesis is represented by which numbered parts of the cycle?

Most animal cells exhibit anchorage dependence, which means that in order to divide

Please use the following information to answer the question(s) below. The unlettered circle at the top of Figure 9.1 shows a diploid nucleus with four chromosomes that have not yet replicated. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is black, and the other is gray. The circles labeled A-E show various combinations of these chromosomes. Figure 9.1 -Which image displays the chromosomal composition of one daughter nucleus at telophase of mitosis?

Please use the following information to answer the question(s) below. Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student-faculty research team introduced labeled T nucleotides into the culture of dividing human cells at specific times. -The research team used the setup to study the incorporation of labeled nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. They concluded that

Researchers began a study of a cultured cell line. Their preliminary observations showed them that the cell line did not exhibit either density-dependent inhibition or anchorage dependence. What could they conclude right away?