A key component that is always important in the proper functioning of the immune system is:
a. direct cell to cell contact.
b. hormonal action.
c. communication between cells.
d. antibody action.
e. perforins
C
You might also like to view...
Using the Sanger method of DNA sequencing, results in the figure below are obtained following gel electrophoresis of the DNA fragments.
 - Word.jpg)
A total of 21 nucleotides has been sequenced. What is the sequence of these nucleotides?
A) 5'-ACCGTTTGCAGAACGTTCCCA-3'
B) 5'-ACCCACGTTAAAGACCCGTTT-3'
C) 5'-AAAAACCCCCCCGGGGTTTTT-3'
D) 5'-ACCCTTGCAAGACGTTTGCCA-3'
E) none of the above
Genes are really just segments of DNA in patterns of As, Ts, Gs, and Cs. How does an RNA polymerase "know" where to start transcribing at the beginning of a particular gene?
A) The polymerase finds the end of the previous gene and copies past that point. B) The polymerase starts transcribing anywhere because the beginning point counts only during translation. C) It looks for a specific promoter region that marks the beginning of a gene. D) RNA polymerase does not know, so it has to rely on the ribosome to help it start at the correct place.
The accompanying image is the product which type of microscope?
a. phase-contrast light microscope
b. Nomarski differential interference microscope
c. transmission electron microscope
d. scanning electron microscope
e. confocal fluorescence microscope
Propose an argument for why the urinary system is much more than just a waste filtration site and is also a major player in the game of homeostasis
What will be an ideal response?