Yes, an organ can be part of one or more organ systems. For instance, the ovary is part of the endocrine and reproductive systems. The skin is part of the integumentary and excretory systems.
8 or more of the 12 organ systems.
an organism because an organism can contain multiple organ systems
The level of organization more complex than a system is the organism. The organism is made up of multiple organ systems working together.
There are more than 5:cardiovascularrespiratorydigestivelymphaticnervousmuscularskeletalreproductiveintegumentary
The skin is actually an organ system called the integumentary system. Like all organ systems, it contains more than one organ.
HYPOTHALAMUS - both endocrine and nervous systems PINEAL GLAND - both endocrine and nervous systems SPLEEN - both cardiovascular and immune systems URETHRA - both urinary (excretory) and reproductive systems
You can learn about the Linux operating system from a number of sources. You can get books on Linux, you can read blogs, or you can ask away in forums.
work more efficiently
you could say its an organ but a more correct term would be a gland.
Organ systems that work together make a more efficient being and help keep a state of balance within the body.