This question is incomplete because the options are missing; here is the missing section:
Which procedure should Juan use to test his hypothesis?
A. Survey northern and southern residents about the birds in their areas.
B. Observe the direction the birds fly when they depart in the winter.
C. Tag the hummingbirds with transmitters and track their movement.
D. Set up observation posts in the south to verify the time of year that birds arrive.
The answer to this question is C. Tag the hummingbirds with transmitters and track their movement.
Explanation:
To prove or disprove his hypothesis about birds Juan needs to test the direction hummingbirds fly to during the winter because only in this way he can know if the birds fly to the South as he thinks or they go to a different place. Moreover, this can better be tested through precise instruments such as trackers because these will register the movement of birds and clearly show if they are going to the South. Moreover, others such as the opinions of residents or the initial direction when birds migrate might be inaccurate.
Proteins
Explanation:
Proteins are the most diverse biomolecule on earth, performing many functions required for life. Protein enzymes are biological catalyst, maintaining life by regulation where and when cellular reactions occur.
-antibodies are proteins that are synthesized by an animal in response to the presence of a foreign substance in our body called an antigen. They play a great role in the immune system and are usually found in blood and other bodily fluids.
Almost all living creatures on our planet depend on plants for food and oxygen, either directly or indirectly. So, if all the plants disappeared, eventually so would almost all the other life. Also, Earth would be hotter.
The correct answer would be The Heart
the heart has valves in place to prevent the backflow of blood.
