Climate Zones Objectives: 1. Describe Earth's major climate zones. 2. Explain how climate zones are characterized. Notes: According to the three cell convection model of each hemisphere the Earth neatly separates itself into three distinct climate zones; the polar, temperate, and the tropical zones.limate Zones Objectives: 1. Describe Earth's major climate zones. 2. Explain how climate zones are characterized. Notes: According to the three cell convection model of each hemisphere the Earth neatly separates itself into three distinct climate zones; the polar, temperate, and the tropical zones.
The nucleus is a large roundish organelle. It is bounded by a double membrane which has numerous pores. Inside the nucleus are chromosomes and a dark region called a nucleolus which makes ribosomes. (Ribosomes are necessary for protein synthesis.)
Free ribosomes are located in the cytoplasm of the cell. They are not attached to any structure, but they may group together with other ribosomes to form polysomes. In the cytoplasm, ribosomes are free floating. They can move all around the cell. Bound ribosomes are located on the surface of the endoplasmic reticulum. The endoplasmic reticulum that contains ribosomes is described as the rough endoplasmic reticulum because of the bumpy surface.