The loudest sounds a nurse hears while listening to a patient's heart through a stethoscope are caused by
A. closing of the AV valves.
B. opening of the semilunar valves.
C. depolarization of the ventricles.
D. contraction of the atria.
E. contraction of the ventricles.
A. closing of the AV valves.
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The insulin receptor is an example of a(n) ____
a. G-protein-coupled receptor b. hydrophobic receptor c. hormone receptor d. receptor tyrosine kinase e. ion channel receptor
You are studying genes in yeast and find that the genes can be placed into four groups that tend to be inherited together. From this you can conclude that yeast
A. have four chromosomes. B. have four loci. C. have four alleles. D. have four genes. E. produce four cells during meiosis.
Each water molecule is joined to _____ other water molecules by ______________ bonds.
a) two ... polar covalent b) four ... hydrogen c) three ... ionic d) four ... polar covalent e) two ... hydrogen
Which of the following statements about Hfr cells and bacterial conjugation is false?
A. An Hfr cell becomes an F- cell if its integrated F plasmid is excised. B. If excision of the F plasmid from an Hfr cell includes some bacterial genes, a partial diploid can result. C. The genes that are transferred from an Hfr cell into a recipient cell during conjugation replace the equivalent genes in the recipient cell. D. An F' plasmid contains some bacterial genes. E. Cells with integrated F' plasmid have two copies of some genes.