Dr. Edward Jenner realized that cows have a disease called cowpox, which is like a disease that infects humans called smallpox; Jenner noticed that milkmaids whose hands were infected with cowpox were not contracting smallpox. Jenner infected a child with the pus from a cowpox blister, and found that the child did not contract smallpox. Which statement represents a supporting hypothesis?
A. The cowpox virus prevented the small pox virus from entering the child's immune system.
B. the smallpox virus was so similar to the cowpox virus that the child's immune system ignored the smallpox virus
C. The cowpox infection will prevent the child from being infected by the small pox virus.
D. The cowpox infection will have no effect on the child's immunity to the small pox virus.
C
You might also like to view...
Upon Darwin's return from his voyage he spent time doing which of the following?
a. breeding dogs b. breeding pigeons c. breeding barnacles d. breeding goldfish e. breeding garden peas
The maximum number of individuals of a species that a given environment can sustain indefinitely defines ____
a. the carrying capacity of the environment b. exponential growth c. the doubling time of a population d. density-independent factors e. density independent factors
Genetic linkage leads to the production of a significantly greater than expected number of gametes containing chromosomes with __________
A) allele combinations that are different from parental combinations B) parental combinations of alleles C) mutant alleles D) dominant alleles E) recessive alleles
If harboring large populations of cycliophorans neither helps nor harms their lobster hosts, then cycliophorans can be properly considered to be _____. 1. parasites 2. mutualists 3. commensals 4. symbionts 5. endosymbionts
A) 1 and 4 B) 3 and 4 C) 2 and 5 D) 3 and 5