Answer:
Arteries have thick walls composed of three distinct layers (tunica) Veins have thin walls but typically have wider lumen (lumen size may vary depending on specific artery or vein) Capillaries are very small and will not be easily detected under the same magnification as arteries and veins.
Explanation:
Answer:
D
Explanation:
If a group of organs working together is called an organ system, and there are about 11 major body systems including the nervous system, the nervour system must be an organ system.
Answer:
The testes
Explanation:
the testes are two oval shaped male reproductive glands that produce sperm and hormone testoterone
Cells —-> Tissues
Tissues ——> Organs
Organs ——> organ systems
Organ systems ——> organism
Organisms ——> populations
Populations ——> community
Communities——-> ecosystem
Ecosystems ——-> biomes
Biomes ——-> biosphere (aka Earth!)
1. Fossil fuels are easy to find and we relied on them for many years
2. pollution and it kills many people
the third one i have not yet figured out sorry i hope this works.