Answer: pressure changes
Valves of the heart open and close due to pressure changes
Explanation:
The veins are the blood vessels possessing valves. And because they carry blood away from the heart, the valves helps to prevent back flow of blood due to the low pressure of blood found in the veins.
Thus, Valves of the heart open and close due to pressure changes
Since it has no nucleus it's most likely a<u><em> prokaryote</em></u>
An organism or type of living thing needs to obtain food, water, shelter and other things it needs to live, grow, and reproduce from its environment. An environment that provides the things an organism needs to live is called its habitat.
I hope this helps you!!
Answer:
The two factors are: moderate temperature and energy source.
Explanation:
A biosphere is that portion of the earth where life occurs which means it consists of water, underground, land, and air. On earth, life can be seen at the bottom of the ocean to 9 km above the earth.
The two major factors that confine living thing to the biosphere is the energy source and moderate temperature. Energy is required by all the organisms present on the earth. Every organism has its own way to gain energy like some gain energy from the sun and some from consuming others.
Moderate and constant temperature is important for the survival of the organisms and to maintain homeostasis in them.
Move closer to Earth shrink in size Move further from Earth
