Answer:
1.A tissue is a collection of similar cells that work together to perform a specific job.
An organ is a collection of different tissues that work together to perform a specific job. The function of a part of an organism is what it actually does (it's job)
2.The structure of the alveoli as a web of blood vessels surrounding an air sac allows blood cells take in oxygen and bring it into the lungs (organ)
The part of the nephron that In which part of the nephron are sodium and chloride ions are actively reabsorbed is the Henle's loop. It <span>is the portion of a </span>nephron<span> that leads from the </span>proximal convoluted tubule<span> to the </span>distal convoluted tubule<span>.</span> It's main function is to make a concentration gradient in the medulla of the kidney.
Following a cut or scrape ....
A Mitosis.
....repairs your skin
Dopamine is a chemical released by neurons to send signals to other nerve cells. the brain includes several distinct dopamine pathways, one of which plays a major role in reward motivated behavior.
smoking is a habit, in a habit there is the cue, routine, and reward. with smoking the cue can be different things, most commonly stress or anxiety. the routine how you react to those cues, the reward is the chemical 'triggers' that are pulled inside you're brain leaving you feeling calm, happy, or relieved, etc.