The countercurrent heat exchanger that prevents arterial blood from overheating the testes is the pampiniform plexus of veins. The pampiniform plexus helps to regulate testicular temperature, allowing sperm maturation. It surrounds the testicular arteries and works as a countercurrent heat-exchanger system to cool the arterial blood before entering the testes. This is because the sperms can not develop if the testis is at body temperature.
Answer: C
Explanation: Smaller single-celled organisms have a high surface area to volume ratio, which allows them to rely on oxygen and material diffusing into the cell (and wastes diffusing out) in order to survive. The higher the surface area to volume ratio they have, the more effective this process can be.
Answer:
Lymphatic: bacteria invade the body but are removed with the help of cells
Endocrine: A chemical message is signaled to help the body relax and sleep
Nervous: The brain signals for the muscles to contract
Explanation:
Lymphatic system is the part in the body that uses the cells in your body to help it.
The endocrine system is about hormones and how the body needs to maintain stable and have homeostasis.
The brain is part of the nervous system and it sends signals to other parts of the body.
Scientist study index fossils so they will get an understanding of what life was like back then.
Answer:
small fish that rely on lily pads for protection will decrease in population.
