Which group would be found on the lowest branch of a phylogenetic tree of all life?
vertebrates
archaebacteria
angiosperms
gymnosperms

I think the correct answer would be the second option. The group of archaebacteria would be found on the lowest branch of a phylogenetic tree of all life. Phylogenic trees are illustrations of a hypothetical evolution of the organisms and its relationship with the other organisms. From the listed options, the archaebacteria is most likely to be the most basic and simplest life form. It should be placed before the other options so at the lowest branch. This illustration is being used by scientists to describe how evolution and the connection of the organisms came about. It sometimes called as the tree of life.

Nervous System: Tissue damage activates pain receptors in the skin. A signal is sent from the peripheral nerve, to the spinal cord where neurotransmitters or chemical messengers are released. This activates other nerves to pass a signal to the brain. The signals are relayed to the somatosensory cortex for pain, sensation, touch, etc.

Neuron: A neuron is a nerve cell that carries electrical impulses. Neurons are the basic units of our nervous system. Neurons have a cell body, dendrites, and an axon, which are nerve fibers. There are about 86 billion neurons in the human brain, which is about 10% of all brain cells.