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.)
Function of the Nucleolus. Ribosomes are made of two subunits, a large and a small. Each subunit is manufactured separately in the nucleolus. The proteins needed to make them enter the nucleus through pores in the nuclear membrane. The rRNA is made in the nucleolus itself.ibosomes are made of two subunits, a large and a small. Each subunit is manufactured separately in the nucleolus. The proteins needed to make them enter the nucleus through pores in the nuclear membrane.