A student claims, "In order to maintain homeostasis, the body utilizes a variety of feedback mechanisms." Which of the following is an example
of a positive feedback mechanism that could be used to support this
statement?
O An increase in body temperature causes humans to secrete a watery fluid in
the form of perspiration. As the fluid evaporates from the skin removing the
excess heat, the body stops perspiring.
O O2 levels in the blood increase and CO2 levels decrease. The brain tells the
muscles of the diaphragm to inhale and exhale more rapidly. As O2 and CO2
levels returns to normal, the organism's breathing returns to normal.
During childbirth, the release of the hormone oxytocin stimulates uterine
contractions, which in turn stimulates the release of more oxytocin.
O High levels of glucose cause the partcreas to secrete more insulin. As
glycogen forms from glucose, glucose levels decline and the pancreas stops
secreting insulin.

On a recent expedition to a remote region of northern canada, scientists uncovered skeletal remains from about 100,000 years ago. surprisingly, all the skeletal remains, which included many species from differing biological families and spanned about two thousand years, showed evidence of experiencing temperatures in excess of 1000 degrees fahrenheit (or 538 degrees celsius). which of the following, if true, best explains the apparent paradox between the cold environment and the evidence of the bones experiencing hot temperatures? (a) chemical changes that naturally occur during the process of decay in only one north canadian species produce the same evidence of the species' skeletons being exposed to hot temperatures as the expedition scientists found. (b) a little over 103,000 years ago, a large fire is known to have occurred in northern canada. (c) strong evidence exists that as early as 70,000 years ago, homo sapiens around the world relied heavily on fire to cook animals. (d) in the same expedition and in roughly the same layer of excavation, scientists found rudimentary wood cutting and hunting tools used by early humans.

Is a measure of the different types of organisms in a community. question options: tertiary secondary primary none of the above

Which statement is true for bacteria a. bacteria have complex internal structures b. all bacteria are spiral in shape c. all bacteria cause disease in animals d. bacteria break down some foods