Answer:
A scientific law is simply an observation of the phenomenon that the theory attempts to explain. For example, suppose that you were lying under an apple tree and observed an apple fall from a branch to the ground. The observation of this phenomena can be called the law of gravity.
thylakoids
Chloroplasts contain saclike photosynthetic membranes called thylakoids, which are interconnected and arranged in stacks known as grana. Pigments are located in the thylakoid membranes. The fluid portion outside of the thylakoids is known as the stroma.
When Linnaeus developed his system of classification, there were only two kingdoms, Plants and Animals. But the use of the microscope led to the discovery of new organisms and the identification of differences in cells. A two-kingdom system was no longer useful. Today the system of classification includes six kingdoms.
The neuron, or nerve cell, is the basic functional unit of the nervous system
A clade is a group of organisms that includes an ancestor and all of its descendants. Clades are based on cladistics. This is a method of comparing traits in related species to determine ancestor-descendant relationships. Clades are represented by cladograms, like the one in Figure below.
