Which of the following describes a positive feedback loop? When blood sugar concentration is too low, the endocrine system secretes hormones that increase blood sugar
concentration to a normal level.
When the body senses that the heart rate is very high, it secretes hormones that decrease the heart rate.
When blood sugar concentration is too high, the endocrine system secretes hormones that decrease blood sugar
concentration to a normal level.
O When someone is exercising intensely, the body secretes hormones that increase oxygen supply for cellular
respiration

List two modern organisms that have pentameral symmetry

Use the drop down menus to match each example to the fossil topic discussed then to show how the fossil record gives evidence of evolution

What is the difference between the conducting zone and the respiratory zone of the respiratory system? the conducting zone is a series of cavities and tubes that move air to the respiratory zone where gases exchange with the bloodstream. the conducting zone exchanges gases between the lungs and the alveoli and the respiratory zone is a series of cavities and tubes that move air to the conducting zone. the conducting zone moves oxygen into the cells and the respiratory zone takes carbon dioxide away from the cells. the conducting zone moves oxygen into the bloodstream and the respiratory zone takes carbon dioxide away from the bloodstream.