Because if they dont they cant make others and other cells need more they spellit a part and if u need less that is diverint story.
Answer:
Scientists can use embryology to determine that many organisms have common ancestors.
Explanation:
Darwin proposed an idea that all species change over time because those that are best adapted to their environments are able to survive and pass on their traits to their offspring. This became known as Darwin's theory of evolution. This historic insight was described based on his observations of the inhabitants of the Galapagos Islands.
Answer:
The correct option is D. (Two back-to-back phospholipid layers with the polar heads facing out on both sides)
Explanation:
The plasma membrane creates a barrier between the interior part of the cell and the cytoplasm. It is consisting of proteins and phospholipids and bi-layered in nature. Phospholipids are known as the main component of the plasma membrane.
Phospholipids are composed of alcohol and fatty acids and they are arranged in a specific manner. Each phospholipid molecule contains a water-hating tail that is hydrophobic in nature and a water-loving head which is hydrophilic in nature and the polar heads face the outside.