4 is true with question you asked
Answer:
Nuclear decay rates are constant
Explanation:
Spontaneous decay of unstable nuclei is a process of a statistical nature, it is not possible to predict with certainty when an individual radioactive nucleus will decay, nor can the decay process be influenced in any way.
Therefore, the half-life of radionuclides (specific for each radionuclide) is defined as the time period in which half of the initial number of radioactive nuclei decays.
The unit of measurement for the radioactivity of the material is the becquerel (Bq) and denotes the number of decays in one second (1Bq = 1 decay / 1 second).
The central vacuole in a plant cell takes up most of the space. The vacuole stores wastes and nutrients, and also provides support and structure for the cell.
I think its A. If you had options like mine
A. In prophase I, tetrads of homologous chromosomes form and crossing over occurs
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