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.)
The nucleus is where the DNA is kept and RNA is transcribed. RNA is moved out of the nucleus through the nuclear pores. Proteins needed inside the nucleus are transported in through the nuclear pores. The nucleolus is usually visible as a dark spot in the nucleus, and is the location of ribosome formation. Ribosomes are where RNA is translated into protein. This process is called protein synthesis. Protein synthesis is very important to cells, therefore large numbers of ribosomes are found in cells. Ribosomes float freely in the cytoplasm, and are also bound to the endoplasmic reticulum (ER).