No, the types of chromosomes vary in shape and number among living things. Humans have linear chromosomes that are arranged in pairs in the cell’s nucleus. However, the reproductive cells or gametes in humans are different in that they do not contain pairs of chromosomes. Instead, gametes carry only one copy of each chromosome. Some animals and plants also have linear chromosomes that are arranged in pairs in the nucleus of the cell. Most bacteria have 1 or 2 chromosomes that are circular in shape.