0.2 mls of a 10-4 dilution of a virus preparation yields 90 plaques. What is the number of PFU per ml in the undiluted virus preparation?
A. 4.5 × 107
B. 9.0 × 108
C. 4.5 × 106
D. 9.0 × 105
Answer: C
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In Arabidopsis the genes TRYPTYCHON and STICHEL are involved in determining
a. how closely trichomes will develop to each other. b. whether or not trichomes are formed. c. which side of a leaf will have trichomes. d. how many branches a trichome will have. e. cell division within trichomes.
Excessive eating
What will be an ideal response?
An island is on the migration route of sea birds. This island also has abundant tree nesting birds that live on the island permanently and are not found on any other island. The tree nesting birds are more likely than the sea birds to be in Hardy-Weinberg equilibrium because:
A. of high immigration in the sea bird population. B. natural selection is stronger in the tree nesting birds. C. mating is random in the tree nesting birds. D. the sea bird population is larger. E. there are fewer mutations in the sea birds.
Which of the following is the longest lasting type of immunity?
a. an adult receiving antiserum/antitoxin injections b. a body receives antibodies to chickenpox across the placenta c. a person survived an infectious disease d. a baby receives antibodies through breastfeeding