What type of normal human cell contains 44 autosomes and two X chromosomes?
A) egg cell
B) somatic cell of a female
C) somatic cell of a male
D) sperm cell
B
You might also like to view...
For sodium to accumulate rapidly in a neuron,
a. a stimulus above the threshold must open sodium gates in an accelerating manner. b. the wave of repolarization must occur to reestablish a resting potential. c. there must be a dramatic increase in the negative charge of the cytoplasm. d. a voltage surge must cause the sodium gates to close. e. the potassium gates must first open.
Water molecules can form hydrogen bonds with _____
A) compounds that have polar covalent bonds B) oils C) oxygen gas (O2 ) molecules D) chloride ions
Blue-footed boobies have webbed feet and are comically clumsy when they walk on land. Evolutionary scientists view these feet as
A) an example of a trait that is poorly adapted. B) the outcome of a trade-off: Webbed feet perform poorly on land but are very helpful in diving for food. C) an example of a trait that has not evolved. D) a curiosity that has little to teach us regarding evolution.
An allosteric transcription regulator called HisP regulates the enzymes for histidine biosynthesis in the bacterium E. coli. Histidine modulates HisP activity
On binding histidine, HisP alters its conformation, markedly changing its affinity for the regulatory sequences in the promoters of the genes for the histidine biosynthetic enzymes. A. If HisP functions as a gene repressor, would you expect that HisP would bind more tightly or less tightly to the regulatory sequences when histidine is abundant? Explain your answer. B. If HisP functions as a gene activator, would you expect that HisP would bind more tightly or less tightly to the regulatory sequences when histidine levels are low? Explain your answer.