Answer:
1. to carry oxygen from the lungs to the body tissues
2. seven (7) or (4)
3.Humans can't live without blood body's organs couldn't get the oxygen and nutrients they need to survive,
Explanation:
1930-1950 hope this helps
Answer: corpus luteum secretion
Explanation:
The crayfish have its nerve cord on the ventral side rather than on the dorsal side. The ventral side is under the Crayfishes' exoskeleton, as opposed to the dorsal side where the exoskeleton is . If it is attacked it will be from the dorsal side and the nerve cord would be snapped easier. The function of the nerve cord is that if it gets attacked by a predator they will go for the top and it will still be able to move.