The blood flows through the vessels of the heart to keep it going
Answer:
Electrons
Explanation:
According to the modern atomic theory, atoms are made-up of smaller subatomic particles in the nucleus. The nucleus contains two types of subatomic particles, protons and neutrons. The protons have a positively electrical charge and the neutrons have no charge. The electrons have a negative electrical charge and are able to move around the nucleus. An atom usually contains an equal number of positively charged protons and negatively charged electrons. This makes the atom itself electrically neutral. The electrons exist at different energy levels, called shells, around the nucleus where they revolve freely in a constant motion.
Answer:
cell wall
Explanation:
Cell wall is the outermost boundary in plant cell whereas plasma membrane or cell membrane is the outermost boundary in animal cells. In a plant cell, cell membrane is found in the inner side of the cell wall.
Hmm.this one is complicated .many factors affect the amount of solar energy an area receives but mainly the length of the solar rays.places close to the equator are hotter because the rays are short and the travel less distance.but away from the equator the rays are longer
