Mastering Biology CH 16 Practice Test – Flashcards
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Specific cells that appear undifferentiated under the microscope but are already fated to become muscle cells are called _____.
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myoblasts
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MyoD promotes muscle cell development by _____.
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turning on the expression of multiple muscle-related genes
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Cytoplasmic determinants _____.
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are coded by maternal genes
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Cells can influence each other's development by a process known as _____.
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induction
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Instead of developing a head and a tail, an abnormal Drosophila embryo develops two tails. This is most likely due to _____.
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a mutation in a maternal effect gene
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Cell differentiation is first observable when _____.
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mRNAs for tissue-specific proteins appear in a cell
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The efficiency of cloning, and the ability to generate healthy cloned animals, has been largely hampered by the difficulty of _____. ()
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completely reversing epigenetic alterations in donor cell nuclei such as DNA methylation and chromatin packing
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Therapeutic cloning" refers to _____.
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the use of cloned embryos as a source of stem cells that could be used to treat disease
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Nuclear transplantation involves _____.
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removing the nucleus of an egg cell and replacing it with the nucleus of a somatic cell
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_____ can give rise to any type of cell whereas _____ can give rise to a subset of cell types.
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Embryonic stem cells ... adult stem cells
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During the process of differentiation, cells _____.
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express different genes in response to cell signaling
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Dolly, the sheep, was cloned from an adult cell. She had a number of health problems and died at a relatively young age. Three mules that were born in 2003 were cloned from fetal cells. If it turns out that the mules remain healthy and live normal lives, how would this outcome tie in with Gurdon's observations with tadpoles?
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Gurdon found that the ability of a transplanted nucleus to direct normal development was inversely related to the age of the donor.
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All of the following are true regarding induced pluripotent stem (iPS) cells except _____.
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iPS cells have been demonstrated to function identically to embryonic stems cells
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A cancer cell _____.
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does not respond to the chemical signals that control cell division
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In the human genome, oncogenes _____.
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stimulate cell division
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Most human cancers are _____.
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caused by the accumulation of somatic mutations
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What gene has been called the "guardian angel of the genome?"
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the p53 gene
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What two genes are often mutated in colon cancer?
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ras and p53
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Why is cancer more prevalent in older people?
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Cancer involves an accumulation of mutations, and older people have had more time to accumulate mutations in their DNA.
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In what way can cancer be hereditary?
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One or two of several mutations necessary for full cancer development can be inherited, giving a person a predisposition to developing cancer.
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The BRCA1 and BRCA2 genes are thought to be what type of genes?
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tumor-suppressor genes
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Which of the following accurately characterizes our current understanding of cancer development?
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In order for a cell to become fully cancerous, it typically must have at least one active oncogene and the mutation or loss of several tumor-suppressor genes.
