Additive genetic effects: A mechanism of quantitative inheritance such that the combined effects of genetic alleles at two or more gene loci are equal to the sum of their individual effects.
- Adducted thumbs with mental retardation
Adducted thumbs with mental retardation: A syndrome with the following characteristic features: neurologically: mental retardation and aphasia (lack of speech) limbs: adducted (clasped) thumbs, absent extensor pollicis longus and/or brevis muscles to the thumb, shuffling gait, and leg spasticity growth: small body size skeleton: lumbar lordosis (sway back) The syndrome is inherited as an X-linked […]
Adduction: Movement of a limb toward the midline of the body. The opposite of adduction is abduction.
- Adductor muscle
Adductor muscle: Any muscle that pulls a body part toward the midline. For example, the adductor muscles of the legs pull the legs toward the midline of the body so the legs are closer together. The word “adductor” comes from the Latin prefix “ad” meaning “toward” + “ducere” meaning “to draw or lead” = “to […]
- Adenine (A)
Adenine (A): One member of the A-T (adenine-thymine) base pair in DNA. The other base pair in DNA is G-C (guanine-cytosine).
Adenitis: Inflammation of a lymph gland. From the aden-, gland + -itis, inflammation.