Write the letter of the matching definition next to each term.
1. Respiration
A. An odorless very poisonous gas that is a product of incomplete combustion of ___
2. Water
B. Obstruction of blood flow in a ___ artery by a blood clot
3. Fibre
C. The metabolic processes whereby certain organisms obtain energy from organic molecules
4. Circulation
D. Organ that pumps blood around the body
5. CarbonDioxide
E. Either of the two main branches of the trachea
6. Lungs
F. An essential structural component of living cells and source of energy for animals
7. Trachea
G. Either of two saclike respiratory organs in the chest of vertebrates (plural)
8. Bronchus
H. Any of several elongated, threadlike cells
9. Heart
I. Gas in the air that we need to breathe
10. Coronary
J. One of the tubules forming the respiratory system of most insects and many arachnids
11. Oxygen
K. Any of various dark heavy viscid substances obtained as a residue
12. Carbohydrate
L. Any skeletal muscle having two origins
13. Protein
M. An alkaloid poison that occurs in tobacco
14. Fats
N. Movement through a ___
15. Vitamins
O. Solid homogeneous inorganic substances occurring in nature having a definite chemical composition (plural)
16. Minerals
P. A binding agreement between two or more persons that is enforceable by law
17. Biceps
Q. Inhaling and exhaling fumes from burning tobacco or other substances.
18. Triceps
R. To become less tense, rest, or take one's ease
19. Contract
S. Clear liquid we drink that falls as rain
20. Relax
T. Nutrient in meat and beans that builds muscle
21. Nicotine
U. Greasy substance in food and body tissue (plural)
22. CarbonMonoxide
V. Any skeletal muscle having three origins
23. Tar
W. A heavy odorless colorless gas formed during respiration and by the decomposition of organic
24. Smoking
X. Any of a group of organic substances essential in small quantities to normal metabolism (plural)