The correct answer is option (A) Variation in the strawberry plants.
When the effect of fertilizer on the growth of two strawberry plants is tested, unavoidable source of experimental error is the variation in the strawberry plants. Variation refers to the deviation or differences from the normal plant which can be due to genetic variation. It is due to change in the DNA sequence. If any one of the two plants being tested show variation, the rate of metabolism differs and changes the growth pattern of the plant. The rate of absorption of water and nutrients is effected which brings change in the growth of the plant and causes an error in the experiment and the result.
There is no picture , what picture ?
<span>Primary endocrine disorders may be due to damage to the hormone producing organ. Karen’s thyroid gland suffered damage from repeated exposure to radiation because of a neck injury. The option which is least likely to be part of a primary endocrine disorder for Karen is decreased osteoblast sensitivity to calcitronin. </span>
A. Moisten and filters incoming air
