Answer:
Telomeres
Explanation:
Telomeres are present at the ends of chromosomes and prevent the lose of genes. They shorten as a person ages. Thus lengthening them may slow down age related problem.
Isotopes are variants of a particular chemical element which differ in neutron number (neutral particle)and all isotopes of a given element have the same number of protons (positive particle) in each atom.So isotope B of the sodium will have 11 protons, 11 electrons but it may have a wide range in its number of neutrons.
The scientific method is a process of steps in order to get a conclusion. First, a scientist will observe something. It could be really anything. Then he/she will ask themselves a question. Like how does it do that? Or why does it do that?
Then they will form a hypothesis. This is where you will ask yourself what will be the outcome of the experiment.
Next you actually perform the experiment. If the experiment comes out as your hypothesis predicted, then you accept your hypothesis.
If not, you reject your hypothesis.
Of course, in science you just don't do one experiment. You do it multiple times and even with different circumstances.
D. It occurs before an organism can reproduce. Meiosis is the replication of sex cells required for sexual reproduction to occur.
When Linnaeus developed his system of classification, there were only two kingdoms, Plants and Animals. But the use of the microscope led to the discovery of new organisms and the identification of differences in cells. A two-kingdom system was no longer useful. Today the system of classification includes six kingdoms.