Prokaryotes and eukaryotes package their DNA molecules with protein in structures called chromosomes. A prokaryotic chromosome is circular and resides in a cell region called the nucleoid.
<span>Around 2.4 billion years ago, the first photosynthetic organisms appeared and used inorganic matter like carbon dioxide and water to produce glucose, with oxygen released in the atmosphere. Because of this, oxygen levels rose; this is called the <em>Great Oxygenation Event</em><span><em>.</em> Through time, photosynthetic organisms evolved to live in land (now as plants). As concentrations of oxygen in the atmosphere became higher, marine animals evolved to utilize oxygen readily available from the atmosphere (rather dissolved in water) hence the evolution of marine animals to land animals capable of respiration in land. </span></span>
Immunoglobulins are produced by D. plasma cells, a type of leukocyte. They are produced in response to the foreign bodies that enter the body. The immunoglobulins are also known as antibodies. The immune response of the antibodies is quite complex and highly specific to the type of antigen it binds to. There are five types of immunoglobulins in the mammals, they are IgA, IgD, IgE, IgG and IgM.
The answer is because aerobic and anaerobic respiration to give us energy.<span />
