Describe how the selective adhesion property of cells was proven
What will be an ideal response?
Easily recognizable cells from the primary cell layers were mixed with an alkaline solution that would
separate the mixture into individual cells. Then the ectoderm and mesoderm from different species
were added together. Initially they stayed as a homogeneous mixture, but then resulted in distinctive
cell colonies of separate ectoderm and mesoderm cells. This indicates that "like" cells have an affinity
for each other and adhere selectively to cells of their own type.
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Which strategy can be used for regulation of metabolism?
A. Feedback inhibition B. Regulation of enzyme synthesis C. Covalent modification of enzymes D. Allosteric regulation E. All of the choices are correct.
DNA contains the template needed to copy itself, but it has no catalytic activity in cells. What catalyzes the formation of phosphodiester bonds between adjacent nucleotides in the DNA polymer being formed?
A) ribozymes B) DNA polymerase C) ATP D) deoxyribonucleotide triphosphates
Which is true of heterotrophs?
A) They capture light energy. B) They cannot be unicellular. C) They store energy in the form of heat. D) They can function as autotrophs in an emergency. E) They can obtain energy by consuming phototrophs.
During a hot afternoon in August, Sara hosted a baby shower for her best friend. Other friends brought much of the food, including a cold cut platter and potato and macaroni salads. They set the food items out on the picnic table in the shade, and then chatted and enjoyed watching their friend open her gifts. It was close to two hours later before they had their meal. Later that evening, eight of the guests who had attended the shower began to feel nauseated and began to vomit severely. The vomiting lasted most of the night, but as morning came, it diminished and they began to recover. What is the most likely cause of the illness?
A. Infection with Salmonella enteritidis B. Botulism C. Infection with E. coli O15:H7 D. Infection with Shigella sp. E. Staphylococcal food intoxication