The circulatory pathways of vertebrates are pictured. Briefly differentiate between the pathways and identify the pathways found in: •amphibians and reptiles •fishes •some reptiles, birds and mammals. Pathway APathway BPathway C 
What will be an ideal response?
Pathway A is found in fishes. This is a single loop pathway involving a two-chambered heart.
Pathway B is found in amphibians and most reptiles. This double loop pathway sends blood to the lungs and to the body. There is some mixing of oxygen-rich and oxygen-poor blood in the single ventricle of the three-chambered heart.
Pathway C is found in some reptiles, birds and mammals. This double loop pathway involves a four-chambered heart. Only oxygen-poor blood is sent to the lungs and oxygen-rich blood is sent to the body.
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Four of the five answers listed below are characteristics of most veins. Select the exception
a. blood volume reservoir b. contain valves c. low resistance-transport tubes d. transport oxygen e. low blood pressure
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after in vitro fertilization on cells from the embryo. b. in the womb, before birth. c. after a woman is pregnant, but before the embryo implants. d. with the help of ultrasound. e. before fertilization on the sperm and the egg.
Bacteria protect themselves from bacteriophage infections by producing restriction enzymes that cut up foreign RNA
of the phage. ____________________ Indicate whether the statement is true or false.