Chapter 11 Review (Biology)
The development of insects such as the fruit fly, Drosophila, consists of two phases. The larva emerges from the egg and after a period of growth, changes into an adult. The adult insect is very different from the larva. The precursor cells for the adult structures are present in small clusters (the imaginal discs) inside the larva. During the larval stage the disc cells do not play a role. However, during metamorphosis the disc cells start to divide and develop into specific adult structures. Compare and contrast the Drosophila development to the development of C. elegans. Choose two correct statements.
-In both C. elegans and Drosophila, a cell's final specialization can be mapped early in the animal's development. -In both C. elegans and Drosophila, cells differentiate into a number of distinct cell types.
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.
-Stem cell treatment should not cause tumors. -Stem cells should not spread beyond the site of the transplant. -Stem cells should not have harmful mutations
Look at the picture. What does it represent? Choose two correct answers.
-The inner mass of cells of the blastocyst will form the specialized cells in the body. -Differentiation is the process by which cells become specialized.
Which of the following statements are typical for cancer cells? Select all that apply.
-They may form tumors that metastasize. -They tend to be unspecialized -They have defective genes
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
Bacteria reproduce ____________ through cell fission. A tube of cytoplasm can temporarily connect two bacterial cells to transfer genetic information. Some DNA passes through this tube. Like ____________ reproduction it causes genetic variation. However, it does not produce offspring.
-asexually -sexual
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.
-because cells with damaged DNA grow and divide uncontrollably -because cell growth and division is no longer regulated by p53 protein -because cells with damaged DNA are not triggered to die
Why do cells divide? Select all that apply.
-to produce new cells during an organism's growth -to replace damaged cells and tissues -to ensure that a cell does not become too large
The two cells are provided with nutrients for growth. After 35 hours, which is the most likely observation of the cells?
Cell 2 has divided twice, while Cell 1 has divided once.
Which advantage of having the a cell's DNA bundled into separate chromosomes is illustrated in Figure 10-1 above?
During cell division, each daughter cell will get the same number of genes.
Chromatids are distributed to the two daughter nuclei.
G1 phase
At the end of this phase, each chromosome is made up of two chromatids.
M phase
Organelles and materials needed for DNA synthesis are made.
M phase
Proteins and other materials needed for cell division are synthesized.
S phase
What is the role of the spindle fibers during mitosis?
They help separate the chromosomes.
What structure is found in prokaryotic cells but not eukaryotic cells?
a single, circular DNA chromosome found in the cytoplasm
This process causes death of abnormal cells.
apoptosis
This process decreases the number of body cells.
apoptosis
This process regulates the cell cycle.
apoptosis
The cells have an abnormal nucleus.
cancer cell
The cells undergo metastasis.
cancer cell
They are non-differentiated cells.
cancer cell
This process increases number of body cells
cell division
This process produces specialized cells.
cell division
This process repairs injuries.
cell division
The ____________ is the point of attachment for sister chromatids.
centromere
The structure labeled A in Figure 10-5 is called the
centromere
The ____________ is an area from which the spindle fibers extend.
centrosome
The ____________ consists of coiled and condensed chromatin.
chromosome
Cancer is a disorder in which some cells have lost the ability to control their
growth rate
The two main stages of cell division are called
mitosis and cytokinesis
Cells with DNA damage undergo apoptosis.
normal cell
The cells are differentiated and specialized.
normal cell
The cells have a normal nucleus.
normal cell
During which phase(s) of mitosis are structures like the one shown in Figure 10-5 visible?
prophase, metaphase, and anaphase
The structures labeled B in Figure 10-5 are called
sister chromatids
The diagram shows the structure of a eukaryotic chromosome. Which of the following events is best represented by the diagram?
the binding of DNA by histones
Which additional observation would provides the strongest evidence that Paramecium reproduces asexually?
the cells in the colony are genetically identical
Which of the following happens when cancer occurs?
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?
the ratio is halved
If the side of a cubical cell doubled, what would the cell then require? Select all the correct answers.
to excrete eight times more waste
What useful purpose is served by cell division in a multicellular organism? Select all the correct answers.
to replace damaged cells and tissues
Cancer cells form masses of cells called
tumors
