Answer:
b) positive feedback loop
Explanation:
The frontostriatal loop is an example of a positive feedback loop.
Answer:
Cell membrane/plasma membrane;
Nucleus;
Cytoplasm
Explanation:
Makena's model is synonymous with that of an animal cell.
The soft flexible putter layer of the egg can be likened to the cell membrane of an animal cell. Cell membrane, also called plasma membrane, just like the soft and flexible exterior of the egg, is a semi-permeable that serves as a barrier between the external environment of the cell and it's inner environment. It controls what goes in and out of the cell, as well as help in the selectively exchange of ions and molecules, in and out of the cell.
The yolk in Makena's model represents the nucleus of an animal cell.
Also, the surrounding area between the yolk and the exterior of the egg, represents the cytoplasm found in animal cells. The cytoplasm is filled with fluids and surrounds the nucleus.
Birds live virtually everywhere on Earth because they have evolved endothermy, the ability to use their metabolism to maintain a constant body temperature.
Birds belong to the class aves; they have an extremely efficient, one way breathing system with additional air sacs. Flying birds have strong, hollow bones and powerful flight muscles. Most birds can fly, they have a strong heart and an efficient way of breathing; which are necessary for birds to fly.
Answer:
You can't see the blood vessels themselves because vision depends on a process that makes it impossible to see things that are stationary with respect to the retina. Light receptors in the retina respond only to changes in light reaching them, not to a steady image.
Have a great day! :D
