Primary reinforcers have distinctive reinforcing qualities; not learned. In addition, secondary reinforcers has no inherent value and only has reinforcing qualities when linked with a primary reinforcers. The positive reinforcement is a desirable stimulus is added to increase behavior while negative reinforcement is an undesirable stimulus is removed to increase behavior.
Answer: Option A
Explanation:
Scientist used the domain Eukarya which comprises the togetherness of all the eukaryotic species. They have been put together because all of the eukaryotic species have their recent common ancestor as eukaryotes.
The first eukaryotic cells, which had nucleus originated 2 billion years ago which had organelles. They explain the endosymbiotic theory.Most of the eukaryotic species that have been evolved from this.
Eukaryotic species have been evolved from another eukaryotic species and share some similar characteristics.
These 2 identical rods of DNA are called sister chromatids, and they are held together at the centromere.
