Speciation<span> is the </span>evolutionary<span> process by which biological populations evolve to become distinct </span>species<span>. The biologist </span>Orator F. Cook<span> coined the term 'speciation' in 1906 for the splitting of lineages or "</span>cladogenesis," as opposed to "anagenesis<span>" or "phyletic evolution" within lineages.</span>
Answer:
The correct answer is "motor unit - motor neuron".
Explanation:
Motor unit and motor neuron are related terms, however they could not be used interchangeably because a motor unit is not comprised only of a motor neuron. A motor unit is made of a motor neuron, skeletal muscle fibers and neuron's axonal terminals. Therefore motor unit is a more broadly term, and is referred to the units that coordinate the contractions of single muscles.
The organisms which appeared on earth first was bacteria.
<u>Explanation:</u>
- The first-ever living organism on Earth was a bacteria known as cyanobacteria. It is believed by scientists that it first formed around 3 billion years ago.
- When the Earth was first formed, it was inhospitable for a long time until 3.8 billion years ago approximately, the core cooled down and the level of oxygen had risen. This, along with photosynthesis resulted in the formation of Cyanobacteria.
- These organisms were capable of carrying out the process of photosynthesis by which they prepared their food. These were known as common ancestors. All the living organisms thereafter are known to be their descendants.
