Chapter 17

As a result of mitosis, the cells of a multicellular organism share which of these properties? Select two correct answers. A. All cells have the same number of chromosomes. B. The number of chromosomes varies among the cells. C. All cells have identical genetic information. D. Genetic information varies among the cells.

A. All cells have the same number of chromosomes. C. All cells have identical genetic information.

Why are cells generally so small? Select all of the answers that apply. A. As they grow, their volume increases faster than their surface area. B. As they grow, their surface area increases faster than their volume. C. Moving nutrients across their cell membranes is more efficient. D. Moving waste materials across their cell membranes is more efficient.

A. As they grow, their volume increases faster than their surface area. C. Moving nutrients across their cell membranes is more efficient. D. Moving waste materials across their cell membranes is more efficient.

Analyze the graph of cyclin levels.Which statement BEST describes the relationship between MPF and the cell cycle? A. Cyclin binds with an enzyme to produce MPF Cyclin, and as its concentration rises, it promotes mitosis. B. Cyclin binds with a factor to produce MPF enzyme, and as the enzyme's concentration decreases, it promotes mitosis. C. The MPF Cyclin concentration remains constant, as the rise and fall of the MPF enzyme controls the cell cycle. D. The MPF Cyclin concentration increases and decreases in a cycle, but does not control the cell cycle.

A. Cyclin binds with an enzyme to produce MPF Cyclin, and as its concentration rises, it promotes mitosis.

Look at the picture. What does it represent? Choose two correct answers. A. Differentiation is the process by which cells become specialized. B. The outer cells of the blastocyst become the embryo. C. The inner mass of cells of the blastocyst will form the specialized cells in the body. D. Specialized blastocyst cells become stem cells in the adult.

A. Differentiation is the process by which cells become specialized. C. The inner mass of cells of the blastocyst will form the specialized cells in the body.

At present, stem cell-based therapies are the clinical standard of care for only a few conditions, including leukemia and macular degeneration. Before stem cell therapies can be ethically approved for other conditions, which safety assessments should be confirmed? Choose three correct statements. A. Stem cells should not have harmful mutations. B. Stem cells should not spread beyond the site of the transplant. C. Stem cell treatment should not cause tumors. D. Stem cell treatment should not overrun costs.

A. Stem cells should not have harmful mutations. B. Stem cells should not spread beyond the site of the transplant. C. Stem cell treatment should not cause tumors.

Compare the surface-area-to-volume ratios of the three spheres representing cells. Which of the three cells, if any, has the greatest surface-area-to-volume ratio?

A. The cell with radius 1

Which of the following happens when cancer occurs? A. The control of the cell cycle is impaired. B. Cells cannot pass the G1 checkpoint. C. Apoptosis or programmed cell death takes place. D. The cells can no longer enter the cell cycle.

A. The control of the cell cycle is impaired.

If a cubical cell with 2-cm sides doubles the dimensions of its sides, what change occurs to the ratio of its surface area to volume? A. The ratio is halved. B. The ratio is doubled. C. The ratio is quadrupled. D. The ratio is quartered.

A. The ratio is halved.

Why are cancer cells harmful? Select all statements that apply. A. They absorb nutrients needed by other cells. B. They block nerve connections. C. They prevent organs from functioning properly. D. They stop cell growth and division.

A. They absorb nutrients needed by other cells. B. They block nerve connections. C. They prevent organs from functioning properly.

Which of the following statements are typical for cancer cells? Select all that apply A. They tend to be unspecialized. B. They undergo apoptosis. C. They may form tumors that metastasize. D. They have defective genes.

A. They tend to be unspecialized. C. They may form tumors that metastasize. D. They have defective genes.

Which of the following limit cell size? Select all of the answers that apply. A. ratio of surface area to volume B. rate of moving materials across the cell's membrane C. efficiency of using the information in a cell's DNA D. efficiency of DNA replication and cell division

A. ratio of surface area to volume B. rate of moving materials across the cell's membrane C. efficiency of using the information in a cell's DNA

What are some treatments for cancer? Select all choices that apply. A. removal by surgery B. treatment with high-energy radiation C. treatment with chemical compounds D. removal by cyclins

A. removal by surgery B. treatment with high-energy radiation C. treatment with chemical compounds

During the development of a multicellular organisms, which cells are totipotent? Select all of the answers that apply A. the fertilized egg and the cells produced by the first few cell divisions B. all cells of the blastocyst, which is a hollow ball of cells and an early embryonic stage C. the germ layers of later embryonic stages D. certain cells in the growing regions of the adult organism

A. the fertilized egg and the cells produced by the first few cell divisions

What useful purpose is served by cell division in a multicellular organism? Select all the correct answers. A. to ensure that a cell does not become too large B. to produce new cells during an organism's growth C. to replace damaged cells and tissues D. to ensure all cells remain undifferentiated

A. to ensure that a cell does not become too large B. to produce new cells during an organism's growth C. to replace damaged cells and tissues

What is the relationship between mutation, the cell cycle, and cancer? Select all statements that apply. A. Mutated genes typically allow cells to respond to checkpoint proteins that halt the cell cycle, thus avoiding formation of tumors. B. As a result of unregulated cell cycles, cells may become cancerous, meaning that the cells grow and divide uncontrollably. C. Cancerous cells may form malignant tumors that invade and destroy surrounding healthy tissue. D. Mutated, defective genes may cause cells to become unable to respond to signals that regulate the cell cycle.

B. As a result of unregulated cell cycles, cells may become cancerous, meaning that the cells grow and divide uncontrollably. C. Cancerous cells may form malignant tumors that invade and destroy surrounding healthy tissue. D. Mutated, defective genes may cause cells to become unable to respond to signals that regulate the cell cycle.

High-energy radiation is often used to treat cancer. Which statement best explains why this treatment is effective? A. The radiation kills cancer cells but leaves healthy cells intact. B. The radiation is especially damaging to cancer cells because of their high rate of mitosis. C. The radiation is especially damaging to cancer cells because of their genetic composition. D. The radiation kills cancer cells and healthy cells equally, but is directed precisely at cancer cells.

B. The radiation is especially damaging to cancer cells because of their high rate of mitosis.

In the human body, stem cells in the bone marrow produce a variety of blood cells. What process produces these cells? A. Differentiated cells divide to produce undifferentiated cells. B. Undifferentiated cells divide to produce differentiated cells. C. Specialized cells of one type divide to produce specialized cells of another type. D. Specialized cells of one type are genetically transformed into specialized cells of another type.

B. Undifferentiated cells divide to produce differentiated cells.

The p53 protein is involved in DNA repair and in triggering cell death when repair is not possible. Why are some cancers associated with defective p53 genes? Select all that apply. A. because in cells with damaged DNA, p53 protein levels rise and cause apoptosis B. because cells with damaged DNA are not triggered to die C. because cell growth and division is no longer regulated by p53 protein D. because cells with damaged DNA grow and divide uncontrollably

B. because cells with damaged DNA are not triggered to die C. because cell growth and division is no longer regulated by p53 protein D. because cells with damaged DNA grow and divide uncontrollably

By regulating the cell cycle, multicellular organisms gain which of these benefits? Select all of the correct answers. A. eliminating unnecessary genes B. healing wounds effectively C. replacing lost cells, such as shed skin cells D. preventing communication among cells

B. healing wounds effectively C. replacing lost cells, such as shed skin cells

An embryo grows into a multicellular organism made of a wide variety of cell types. How does the variation in cell types occur? A. Each type of specialized cell produces another type in an ordered sequence. B. Muscle and connective tissue in the embryo produce the other types of specialized cells. C. Embryonic stem cells divide to produce all types of specialized cells. D. Embryonic stem cells divide to produce nerve cells, which produce all types of specialized cells.

C. Embryonic stem cells divide to produce all types of specialized cells.

Paramecium is a single-celled protozoan. The graph shows a typical growth curve for a colony of Paramecium in a nutrient culture. Two Paramecium cells sometimes engage in a sexual process in which genetic materials are exchanged, but no new cells are produced.Which additional observation would provides the strongest evidence that Paramecium reproduces asexually? A. The cells in the colony are genetically different from one another. B. The colony begins decreasing in number after Day 14. C. The cells in the colony are genetically identical. D. The cells in the colony become smaller over time.

C. The cells in the colony are genetically identical.

In eukaryotic cells, DNA is packaged with proteins into structures called chromosomes. What advantage do chromosomes provide the cell? A. They allow all genes to be expressed at the same time. B. They allow random distribution of genetic material when a cell divides. C. They ensure equal division of genetic material when a cell divides. D. They eliminate the need for a nuclear membrane.

C. They ensure equal division of genetic material when a cell divides.

Which is the most likely application of stem cell research? A. a cure for cancer, a disease in which cells divide rapidly and without proper control B. a treatment for viral infections, in which viruses invade cells C. a treatment for macular degeneration, in which cells of the eye are damaged or killed D. a cure for genetic disorders, which are inherited from either or both parents

C. a treatment for macular degeneration, in which cells of the eye are damaged or killed

Read each of the statements that describe cancer cells and normal cells. Then drag each statement into the correct box.

Cancer cell - The cells have an abnormal nucleus, They are non-differentiated cells, The cells undergo metastasis. Normal cell - The cells have a normal nucleus, Cells with DNA damage undergo apoptosis, The cells are differentiated and specialized.

A physician takes a biopsy, or tissue sample, from the skin of a patient. Which observation of the cells in the tissue would most strongly support the conclusion that the patient has skin cancer? A. Many cells in the tissue sample appear identical to one another. B. All of the cells are packed closely together. C. Some of the cells were dead when the biopsy was obtained. D. A group of cells appear larger and rounder than surrounding cells.

D. A group of cells appear larger and rounder than surrounding cells.

Analyze the cell cycle diagrams of two different types of cells. Compare and contrast the length of time each cell takes to complete the G1 phase of the cycle. The two cells are provided with nutrients for growth. After 35 hours, which is the most likely observation of the cells? A. Both cells have divided into two daughter cells. B. Both cells are in the S phase of the cell cycle. C. Both cells are in the M phase of the cell cycle. D. Cell 2 has divided twice, while Cell 1 has divided once.

D. Cell 2 has divided twice, while Cell 1 has divided once.

Which of these events happens immediately before cell division occurs? A. The cell's DNA is distributed evenly throughout the cell. B. The cell's surface-area-to-volume ratio increases. C. The cell's volume decreases more than its surface area. D. The cell's genetic material is copied.

D. The cell's genetic material is copied.

The drug colchicine inhibits the formation of spindle fibers during mitosis. If you treat dividing plant cells with colchicine, what would you expect the result to be? A. The chromosomes are halved during cell division and the result is a cell that has half the number of chromosomes than it would normally have. B. The chromosomes do not pull apart in an orderly fashion during cell division and the result is two cells with unequal numbers of chromosomes. C. The chromosomes are separated during prophase and each of the four daughter cells receives a haploid number of chromosomes. D. The chromosomes do not pull apart during cell division and the result is a cell that has double the number of chromosomes than it would normally have.

D. The chromosomes do not pull apart during cell division and the result is a cell that has double the number of chromosomes than it would normally have.

How does the size of a cell's surface area change compared to its volume when the cell grows? A. The surface area remains constant as the volume changes. B. The surface area increases at the same rate the volume does. C. The surface area increases faster than the volume does. D. The surface area does not increase as fast as the volume does.

D. The surface area does not increase as fast as the volume does.

What structure is found in prokaryotic cells but not eukaryotic cells? A. a shorter, condensed chromosome in the nucleus B. a chromosome that contains many histones C. a chromosome found within a membrane-bound nucleus D. a single, circular DNA chromosome found in the cytoplasm

D. a single, circular DNA chromosome found in the cytoplasm

If the side of a cubical cell doubled, what would the cell then require? Select all the correct answers. A. eight times more nutrients B. to excrete eight times more waste C. four times more nutrients D. to excrete four times more waste

D. to excrete four times more waste

Analyze the graph of cyclin levels.When does the Mitosis-promoting factor (MPF) Cyclin concentration decline during a typical cell cycle in clam eggs? A. when the cells grow larger B. when DNA is synthesized C. when haploid gametes are produced D. when the cell nucleus divides

D. when the cell nucleus divides

Japanese scientists were able to create pluripotent stem cells (iPS), a type of stem cell that is similar to embryonic stem cells. The researchers were then able to grow heart and brain cells from these stem cells. Choose the statements that explain the similarities and differences of iPS cells and embryonic stem cells. Place each statement into the correct box.

Embryonic stem cells - are made from the inner cell mass of the blastocyst iPS cells - are made from mouse fibroblasts, are made from adult cells Both types of stem cells - heart, brain and other differentiated cells can grow from them, can possibly be used for therapeutic treatments

Read each of the statements that describe the function of a cell cycle regulator. Then drag each sentence into the correct category.

Internal Regulators -regulates checkpoints, makes sure chromosomes have replicated External regulators - speeds up or slows down cell cycle, stops cell cycle

The cell nucleus and the cytoplasm divide among two new cells. DNA is synthesized, and single-stranded chromatids become double stranded. Cells grow at a rate that varies between the two cell types. Cells grow at a rate that is the same in the two cell types.

M, S, G1, G2

Compare and contrast some features of prokaryotic and eukaryotic cells. Match each statement with the correct cell type.

Prokaryotic Cell - Lack of membrane-bound nucleus, DNA in cytoplasm, Single, circular chromosome Eukaryotic Cell - Membrane-bound nucleus, DNA inside nucleus, Multiple chromosomes

If an organism is successful in a particular environment, reproduction is . However, if an environment changes, some offspring of reproduction may have a better chance of survival and reproductive success than others in a population because of

asexual, advantageous, sexual, genetic variability

When conditions in the environment change, a lack of genetic diversity may be disadvantageous for organisms that reproduce . Genetic diversity may be advantageous for organisms that reproduce when conditions in an environment change.

asexually, sexually

The is the point of attachment for sister chromatids. The is an area from which the spindle fibers extend. The consists of coiled and condensed chromatin.

centromere centrosome chromosome

Cell division occurs in two stages: division of the nucleus, called , and division of the cytoplasm, called

mitosis, cytokinesis

Place each statement in the correct box.

Apoptosis - This process decreases the number of body cells, This process causes death of abnormal cells, This process regulates the cell cycle. Cell division - This process increases number of body cells, This process produces specialized cells, This process repairs injuries.

Compare asexual and sexual reproduction. Place each statement into the correct box.

Asexual reproduction - Offspring are genetically identical to their single parent, Results in a lack of genetic diversity Sexual reproduction - Offspring inherit some of their genetic information from each parent, Produces genetic diversity