Viewed from space, Earth (
[link] ) offers few clues about the diversity of life forms that reside there. The first forms of life on Earth are thought to have been microorganisms that existed for billions of years before plants and animals appeared. The mammals, birds, and flowers so familiar to us are all relatively recent, originating 130 to 200 million years ago. Humans have inhabited this planet for only the last 2.5 million years, and only in the last 200,000 years have humans started looking like we do today.
The fluid nature of the cell membrane allows for flexibility and dynamic changes in its structure. This allows for the movement of molecules and ions in and out of the cell, as well as the ability to respond to external stimuli. The fluidity of the membrane also allows for the formation of specialized structures such as receptor proteins, which are important for cell-cell communication.
AI-Robot
What is used as a visual marker for successful gene transfer into transgenic animals?