Answer:
The correct answer is - To withstand the high pressure of the outflow of blood from the Heart.
Explanation:
The heart pumps blood to different body parts at high pressure so that it can easily reach all the parts of the body quickly. To able to hold the pressure of the blood pumped at high-pressure arteries need thick walls.
This pressure can be experienced as pulse and which required the walls of arteries and the middle layer or the tunica media to make it much thicker in arteries than in veins. In veins pressure caused by blood is very low pressure that allows them to be thin walls.
Answer:
All mammals, like dogs, cats, and humans; reptiles, amphibians, fish, birds, and even insects.
Explanation:
All mammals, like dogs, cats, and humans; reptiles, amphibians, fish, birds, and even insects are the animals that have a complete tube-like gut with two openings. A system having a tube with two openings i.e. mouth and an anus is called tubular system. In this tubular system, the animals eat with one opening and the other opening is used for excretion of waste and nitrogenous materials from the body so that's why most of the animals have two openings.
To calculate the population density, you will divide the population by the size of the area. Hope I helped!
Recycling cells division. meoisis theroy