Answer: The parasympathetic nervous system and sympathetic nervous system play opposite roles
Explanation:
To ensure a stable internal environment (homeostasis) is achieved, the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS) play OPPOSITE roles.
The PNS dominate during relaxed periods and stimulates the
- liver to break down glycogen
- constriction of bladder to pass out urine
- increases heartbeat
- dilate pupils etc
The SNS, in contrast dominate in times of emergency or stressful periods and do the EXACT opposite of the processes mentioned above.
Thus homeostasis is maintained
Answer: The most accepted guess is: By bamboo rafts.
Explanation:
There are two hypotheses.
The first is that they arrived on Flores as Homo erectus and then evolved to Homo floresiensis. The second is that they were already Homo floresiensis when they arrived. This second one is the more accepted hypothesis because it would take organization and language to accomplish this technological water transportation feat. Homo erectus is not known to have developed speech.
Now at the time this transport was estimated to have happened, 100000 years ago, the islands of Komodo and Flores were joined and visible from the mainland. Together they constituted a 19km wide straight visible that could be easily seen from the mainland. The Homo floresiensis tribes built bamboo rafts, or possibly some other floating apparatus made if wood, and sailed there. The islands then progressively drifted apart, isolating them.
PS: It is important to note that some things may have drove them there such as famine, violence, etc.
Answer: Homo erectus DNA is too similar to ours to prevent contamination.
Explanation:
Homo erectus fossils are known as the oldest form of early humans that had human like body structure with shorter arms and elongated legs and shorter arms. These features gave them the ability to walk and also run long distances.
The reason that we do not have a genome sequenced from Homo erectus is that their DNA is too similar to ours to prevent contamination. There are enough fund which could have been used to carry out the research but their similarities to human beings has been the source of concern.
Answer:
A few basic components comprise a jackscrew. The main piece is the screw itself. The screw may be connected to a plate of some kind housing a load or attached to another piece of machinery that is then moved.
