Answer:
at high altitudes ! hopefully this helps ^-^
Blood vessels expand during hot weather and retract/ tighten in cold weather
Answer:
d
Explanation:
<em>The correct answer would be increasing heart rate to compensate for low cardiac output.</em>
The negative feedback loop is the mechanism that is utilized in the maintenance of homeostasis. They work by opposing the processes that bring about a deviation away from setpoints, that is, the normal range of operation of physiological processes in the body.
<u>For example, when the heart rate goes below the setpoint, the negative feedback loop swings into action through the sensor, the control center, and the effector to return the heart rate to the normal operating range.</u>
Correct option: d
Answer: why it is hard to use dichotomous key in the lab are;
If the organisms you want to use it for are similar.
If you can't see the little characteristics posses by the organisms you are using it for.
If all the pictures does not reveal all the important features of the organisms.
It is very difficult to use it to determine the anatomical structure.
Explanation:
Dichotomous key is an important method that is use in biology to identify organisms by separating or dividing the organisms into two groups. It is a tool created by scientists to help them identify organisms or objects. Once the organisms are group into two, more information is revealed more individually.

¿What are invertebrates?
Invertebrates are unicellular or multicellular organisms that present a great variety of habits and morpho-functional patterns.
Which are classified into :-
Anthropods, molluscs, worms, echinoderms, coelenterates, and porifera.
I hope I've helped : )