Crunches are designed to strengthen your abdominal muscles If you hurt your arms to get up, then you are not following the principle of , because you are using your back and arm muscles instead of your abdominal muscles Progression

Regularity

Overlaod

Specificity

None of the above

Group of genes that encode molecules found in all body cells, creating a biochemical “fingerprint” that serves as the “id” for cells so that they are marked as “self” a) deoxyribonucleic acid (dna) b) entry inhibitors c) major histocompatibility complex (mhc) d) non-nucleoside reverse transcription inhibitors (nnrtis)