A radioactive element is an element which is subject to spontaneous degeneration of its nucleus followed by the emission of alpha, beta and gamma particles. All elements with atomic numbers greater than 83 are radioactive.
The given phrases that describe radioactive elements are-
They have a consistent number of particles
- the particles are alpha, beta and gamma particles.
They have a half-life that determines their rate of decay.
Explanation for other options:
Not all elements occur in nature. Radioactive decay rates may not be constant as the decay happens when a radioactive substance emits a particle. It is not possible to predict exactly when a given atom of a substance will emit a particular particle. When the radioactive element release energy and particles, it decays.
Answer:
It recognizes and binds to a pair of "mismatched" nucleotides, preventing their translation.
Explanation:
Mut L protein is involved in mismatch DNA repair. MutL protein is complexed with MutS protein and the MutL-MutS complex recognizes all the mismatched base pairs present in the newly formed DNA strand. The complex can not recognize the "C-C" pairs. MutH protein joins the complex.
The MutH protein also has a site-specific endonuclease activity and cleaves the unmethylated DNA strand towards the 5' end of the guanine base in the GATC sequence to mark the strand for DNA repair. In this way, MutL protein, along with MutS and MutH proteins mark the mismatched DNA bases for repair so that they are not translated into a faulty protein.
