The answer A. DNA in the nucleus controls all cell activity.
The answer is D. Because the bird has to be noticed and the brighter the feathers the more likely the chance to be noticed.
The definition of cell theory is as follows: <span>a </span>theory<span> in biology that includes one or both of the statements that the </span>cell<span> is the fundamental structural and functional unit of living matter and that the organism is composed of autonomous </span>cells<span> with its properties being the sum of those of its </span>cells<span>.</span>
The reasons why 241am smoke detectors are perfectly safe is because;
(i) The amount of americium is very little.
(ii) The aluminium core is where the detector is hosted.
(iii) The detector has a plastic cover.
(iv) Radiation is limited in penetrating power.
(v) There is a low number which is leaving the case.
(iv) ions get trapped by electrodes.