please help!! Biology questions 1.Red blood cells...?

[pokiejoke]

A. transport respiratory gases
B. combat bacterial infection
C. destrot viruses
D. transport cholesterol

2.Steroids are able to enter their target cells...
A. after combining with protein
B. because they are made of DNA
C. inorder to produce cyclic AMP
D. because they are fat-soluble

3. Which of the following would not be influenced by cyclic AMP?
A. activation of enzyme within a target cell
B. inhibition of the chemical activities within a target cell
C. increases in the gene activity of a target cell
D. amplification of the effect of a peptide hormone

4. If a blood vessed has valves, it probably...
A. is a vein
B. is an artery
C. is a venule
D. is part of the lymphatic syatem

5. The pulmonary circulation flows to and from the...
A. stomach
B. liver
C. intestines
D. lungs

[Peter V]

3 is D> poster one is right for the rest.