No predators exist to eat them and keep the population at a stable size.
Answer:
Explanation:
The circulatory system consists of typically two organs these are the heart which also belong to the cardiovascular system and the lungs which also belong to the respiratory system these are connected to the arteries, veins and other blood vessels. The lungs receives the oxygen which diffuse oxygen into the blood vessels which transports the oxygenated blood to the heart which is pumped and circulated by the heart to all the parts of the body.
To determine whether a cell is a eukaryotic or
prokaryotic cell, one can observe certain features.
If the cell in the question possesses a well-defined
or definite nucleus and have membrane-bound
organelles such as mitochondria, chloroplasts,
Golgi apparatus, endoplasmic reticulum, the cell is
eukaryotic. If the cell has nucleoid or indefinite
nucleus and without membrane-bound cell
organelles, the cell is prokaryotic. If ribosomes in
a cell are the 80S (S=Svedberg units) type, the cell
is eukaryotic and if ribosomes are 70S type then it
is prokaryotic.