Multicellular organisms e.g. man meet their needs through use of specialized systems that they have in their bodies. Examples of such include:
1. cardiovascular system composed of heart, veins and arteries which facilitate transport of nutrients to all parts of the body .
2. Skeletal system composed of bones, joints, ligaments and cartilage whose function is support and protection of the body.
3. Digestive system composed of mouth, esophagus, stomach , small and large intestines whose function is breakdown of food and absorption of nutrients.
The Human Development Index is a statistic composite index of life expectancy, education, and per capita income indicators, which are used to rank countries into four tiers of human development.
Six:
1. Upper Mississippi
2. Arkanas River
3. Illinois River
4. Missouri River
5. Ohio River.
6. Red River
The Prime Meridian marks zero degrees longitude. Without it, the other degrees of longitude cannot be measured.
