Answer:
during time periods where algae is not readily available as a food supply, survive for months.
Explanation:
Answer:
The cornea is the only part of a human body that has no blood supply but gets oxygen directly from air
Answer: In the stomach, oesophagus and intestines.
Explanation: Parastalsis is an involuntary wave-like movement of the bolus(food) and chyme by muscle contractions in the digestive tract. It occurs in the oesophagus, stomach and intestines. This happens by relaxation of circular smooth muscles allowing the bolus to pass and contract again to propel it forward. It goes on like that until it is secreted in the anus. Parastalsis is not limited to the digestive tract but also takes place in other hollow tubes in the body.