Kingdoms are classified into three Domains and into one of the six kingdoms of life.
No, this is false!
Renewable resources can be syntesized by humans, or not: some of them can, and some can't. This is not what makes them renewable, instead it's the fact that they will still be present in the nature after usage - they will be replaced (the sun will still shine tomorrow even if we harvest its power).
The correct term to fill in the blank would be cortisol. In the context of stress hormones and the brain, cortisol has a profound effect on the hippocampus, a brain structure that plays a pivotal role in memory. Cortisol is classified as a steroid hormone which is produced by the adrenal gland. It is deemed as the stress hormone as it is released as a response to stress as part of the fight or flight process. From studies, cortisol was found to have effect on the hippocampus when present in high levels. It damage and kill the cells in that area of the brain. The hippocampus is the area of the brain that is responsible for the long term memory storage. So, when this part is damage then the storage for our memories would surely be affected.
High-density means full and low density is more empty