About 160 years. After Charles Darwin came out with his theory people have been debating it.
Earth's tilted axis causes the seasons. Throughout the year, different parts of Earth receive the Sun's most direct rays. So, when the North Pole tilts toward the Sun, it's summer in the Northern Hemisphere. And when the South Pole tilts toward the Sun, it's winter in the Northern Hemisphere.
DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base.
Answer:Myocardium
Explanation: Myocardium is the middle layer of the heart wall. It is also the muscle tissue of the heart.
Myocardium is the thickest layer of the heart wall. It is madeup of cardiac muscle cells. These muscle cells possess contracting capability like other muscle cells.
