Answer:
Positive feedback is used to build more contractions.
Explanation:
Positive feedback mechanism in humans is also observed during childbirth which is induced by the pressing of the ovarian wall by the baby.
The pressing sensation is passed to the brain via different nerves, and in response, the brain stimulates the pituitary to produce oxytocin.
Oxytocin is responsible for the contractions of the uterine muscles which cause the movement of the fetus towards the cervix, further increasing the stimulus.
The positive feedback loop continues until the baby is born.
Polymorphic. Polymorphisms
refer to spasmodic genetic variation within the same species of an organism resulting in varying forms of the species. Polymorphic viruses, mutate at faster rates hence the virus
population is subject to high rates of turnovers. The high divergence of various
species, such as influenza, is as a result of 0.01 mutations per nucleotide site
per year.
Plant store there food in there roots.
The answer is microscopic life appeared on Earth before flowering plants. This is because according to the label on the second box, microscopic life appeared 4.0 to 3.5 billion years ago, and this is way before the date 250 to 120 millions years ago indicated on the label on the sixth box the flowering plants appeared on Earth.
Discontinuous variable ;)